Control of Emissions From Highway Motorcycles

Federal RegisterJan 15, 2004

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 9, 86, 90, and 1051

[AMS-FRL-7604-8]

RIN 2060-AJ90

Control of Emissions From Highway Motorcycles

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Final rule.

SUMMARY:

In this action we are adopting revised exhaust emission standards for currently regulated highway motorcycles. We are also adopting new exhaust emissions standards for motorcycles of less than 50 cubic centimeters in displacement, which had not previously been subject to EPA regulations. Finally, we are adopting new permeation evaporative emission standards for all classes of highway motorcycles. Highway motorcycles contribute to ozone and particulate matter (PM) nonattainment, as well as other types of pollution impacting human health and welfare.

We expect that manufacturers will be able to maintain or even improve the performance of their products without compromising safety when producing highway motorcycles in compliance with these standards. In fact, we estimate that the fuel costs savings associated with these regulations will offset about one fourth of the program's cost by the time the standards are fully phased in (2030). There are also several provisions to address the unique limitations of small volume manufacturers.

EFFECTIVE DATE:

This final rule is effective March 15, 2004.

ADDRESSES:

Materials relevant to this rulemaking are contained in Public Docket Numbers A-2000-01 and A-2000-02 at the following address: EPA Docket Center (EPA/DC), Public Reading Room, Room B102, EPA West Building, 1301 Constitution Avenue, NW., Washington, DC. The EPA Docket Center Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, except on government holidays. You can reach the Reading Room by telephone at (202) 566-1742, and by facsimile at (202) 566-1741. The telephone number for the Air Docket is (202) 566-1742. You may be charged a reasonable fee for photocopying docket materials, as provided in 40 CFR part 2.

For further information on electronic availability of this action, see

SUPPLEMENTARY INFORMATION

below.

FOR FURTHER INFORMATION CONTACT:

U.S. EPA, Office of Transportation and Air Quality, Assessment and Standards Division hotline, (734) 214-4636,

asdinfo@epa.gov.

Carol Connell, (734) 214-4636;

connell.carol@epa.gov.

SUPPLEMENTARY INFORMATION:

Regulated Entities

This action will affect companies that manufacture or introduce into commerce highway motorcycles subject to the standards. This includes motorcycles with engines with a displacement of less than 50 cubic centimeters (cc) provided the vehicle otherwise meets the regulatory definition of a highway motorcycle. Regulated categories and entities include:

Category

NAICS Codes

SIC Codes

Examples of potentially regulated entities

Industry

336991

Motorcycle manufacturers.

Industry

421110

Independent Commercial Importers of Vehicles and Parts.

Notes:

North American Industry Classification System (NAICS).

Standard Industrial Classification (SIC) system code.

This list is not intended to be exhaustive, but rather provides a guide regarding entities likely to be regulated by this action. To determine whether this action regulates particular activities, you should carefully examine the regulations. You may direct questions regarding the applicability of this action to the person listed in

FOR FURTHER INFORMATION CONTACT.

How Can I Get Copies of This Document and Other Related Information?

Docket.

EPA has established an official public docket for this action under Docket ID Nos. OAR-2002-0024, A-2000-01, and A-2000-02. The official docket consists of the documents specifically referenced in this action, any public comments received, and other information related to this action. Although a part of the official docket, the public docket does not include Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. The official public docket is the collection of materials that is available for public viewing at Air Docket in the EPA Docket Center, (EPA/DC) EPA West, Room B102, 1301 Constitution Ave., NW., Washington, DC. The EPA Docket Center Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Reading Room is (202) 566-1742, and the telephone number for the Air Docket is (202) 566-1742.

Electronic Access.

You may access this

Federal Register

document electronically through the EPA Internet under the

Federal Register

listings at

http://www.epa.gov/fedrgstr/

An electronic version of the public docket is available through EPA's electronic public docket and comment system, EPA Dockets. You may use EPA Dockets at

http://www.epa.gov/edocket/

to view public comments, access the index listing of the contents of the official public docket, and to access those documents in the public docket that are available electronically. Although not all docket materials may be available electronically, you may still access any of the publicly available docket materials through the docket facility identified above under the heading “Docket.” Once in the system, select “search,” then key in the appropriate docket identification number.

Table of Contents

I. Introduction

A. Background

B. How Is This Document Organized?

C. What Requirements Are We Adopting?

D. Putting This Action Into Perspective

E. Statutory Authority

F. Modification, Customization and Personalization of Motorcycles

G. Future Actions

II. Why Is EPA Taking This Action?

A. What Are The Health and Welfare Effects of Highway Motorcycle Emissions?

B. What Is the Emission Inventory Contribution From Highway Motorcycles?

III. Which Vehicles and Engines Are Covered?

A. What is a Highway Motorcycle?

B. What are Class I, Class II, and Class III Highway Motorcycles?

IV. Exhaust Emission Standards and Test Procedures

A. What are the New Exhaust Emission Standards?

B. Can I Average, Bank, or Trade Emission Credits?

C. What are The Applicable Test Procedures?

D. What Test Fuel Is Required for Emission Testing?

E. Hardship Provisions

F. Special Compliance Provisions for Small Manufacturers

G. Exemption for Motorcycle Kits and Custom Motorcycles

V. Technological Feasibility of the Exhaust Emission Standards

A. Class I Motorcycles and Motorcycle Engines Under 50cc

B. Class I and Class II Motorcycles Between 50 and 180cc

C. Class III Motorcycles

D. Safety and Performance Impacts

E. Non-Conformance Penalties

VI. Permeation Emission Control

A. Overview

B. Permeation Emission Standards

C. Testing Requirements

D. Special Compliance Provisions

E. Technological Feasibility

VII. Environmental Impacts and Program Costs

A. Environmental Impacts

B. Motorcycle Engine and Equipment Costs

C. Aggregate Costs and Cost-Effectiveness

VIII. Public Participation

IX. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

B. Paperwork Reduction Act

C. Regulatory Flexibility Act (RFA), as Amended by the Small Business Regulatory Enforcement Fairness Act of 1996 (SBREFA), 5 U.S.C. 601

et seq.

D. Unfunded Mandates Reform Act

E. Executive Order 13132: Federalism

F. Executive Order 13175: Consultation and Coordination with Indian Tribal Governments

G. Executive Order 13045: Protection of Children from Environmental Health and Safety Risks

H. Executive Order 13211: Actions that Significantly Affect Energy Supply, Distribution, or Use

I. National Technology Transfer and Advancement Act

J. Congressional Review Act

K. Plain Language

I. Introduction

A. Background

Air pollution is a serious threat to the health and well-being of millions of Americans and imposes a large burden on the U.S. economy. Ground-level ozone, carbon monoxide, and particulate matter are linked to potentially serious respiratory health problems, especially respiratory effects and environmental degradation, including visibility impairment in our national parks.

This rule addresses these air pollution concerns by adopting national emission standards for highway motorcycles, including a category of motorcycle that is currently unregulated. These new standards are a continuation of the process of establishing emission standards for on-highway engines and vehicles under Clean Air Act section 202(a). We are adopting new exhaust emission standards and new standards for permeation emissions from highway motorcycles.

Over the past quarter century, state and federal governments have established emission-control programs that significantly reduce emissions from numerous types of sources. Many of these sources now pollute at only a small fraction of their pre-control rates. In contrast, today's rule revises EPA standards for on-highway motorcycles for the first time since 1977.

These final standards for motorcycles reflect the development of emission-control technology that has occurred since we last set standards for these engines which took effect in 1978. A review of current motorcycle certification results clearly indicates that the emissions performance of a majority of current motorcycles surpasses levels required by current federal regulations. The standards established in this rule will further lower emissions in the next 3-7 years.

See

42 FR 1122, Jan. 5, 1977.

Nationwide, highway motorcycles are significant contributors to mobile-source air pollution, currently accounting for 0.6 percent of mobile-source hydrocarbon (HC) emissions, 0.1 percent of mobile-source oxides of nitrogen (NO

) emissions, and less than 0.1 percent of mobile-source particulate matter (PM) emissions.

Without these further regulations, highway motorcycles would account for 2.2 percent of mobile source HC, 0.3 percent of mobile source NO

, and 0.1 percent of mobile-source particulate matter (PM) emissions by 2020. These standards will reduce exposure to these emissions and help avoid a range of adverse health effects associated with ambient ozone and PM levels, especially in terms of respiratory impairment and related illnesses. In addition, the standards will help reduce acute exposure to air toxics and PM for persons who operate or who work with or are otherwise active in close proximity to these sources. They will also help address other environmental problems associated with these sources, such as visibility impairment in our national parks and other wilderness areas.

While we characterize emissions of hydrocarbons, this can be used as a surrogate for volatile organic compounds (VOC), which comprises a very similar, but slightly different, set of compounds. Hydrocarbons are generally easier to test for, and therefore, are easier to regulate.

This final rule follows several EPA notices: An Advance Notice of Proposed Rulemaking (ANPRM) published on December 7, 2000 (65 FR 76797); a Notice of Proposed Rulemaking (NPRM) published on August 14, 2002 (67 FR 53050), and an additional notice dated October 30, 2002 (67 FR 66097). In the NPRM we proposed new exhaust emission standards for highway motorcycles, including motorcycles of less than 50 cubic centimeters (cc) in displacement, and requested comment on promulgating standards controlling emissions from fuel tank and hose permeation from highway motorcycles.

We received comments on the NPRM from a wide variety of stakeholders, including the motorcycle manufacturing industry, motorcycle user groups, various governmental bodies, environmental groups, and the general public. These comments are available for public viewing in Docket A-2000-02. Our responses to these comments are detailed in the Summary and Analysis of Comments, which is available in the docket and on our Web site.

The NPRM also proposed provisions for controlling evaporative emissions from marine vessels that use spark-ignition engines. These provisions are not a part of this action; a final rule addressing these provisions is being developed and will be published in a separate future action.

B. How Is This Document Organized?

This final rule covers highway motorcycles, which vary in size from small scooters with engines of less than 50cc displacement to large touring models with engines that approach the size of small automobile engines (over 1000cc). In general the text is often organized by EPA's definitions of motorcycle classes, which are based on the size of the engine and are used to distinguish motorcycles for the purposes of applying emission standards.

Section I describes the general provisions that we are finalizing and provides some background and context for the final rule.

Section II describes the air quality needs that cause us to publish this final rule, as well as describing how highway motorcycles contribute to air pollution.

Section III describes specifically which vehicles are covered by the final rule.

Section IV describes the new exhaust emission standards and related provisions that we are finalizing.

Section V describes our findings regarding the technological feasibility of the exhaust emission standards for highway motorcycles.

Section VI describes the permeation evaporative emission standards and related provisions that we are finalizing. It also describes the permeation testing requirements and our findings regarding the technological feasibility of the permeation requirements.

Section VII summarizes the projected environmental impacts and costs of this rule. We expect the costs of this emission control program to be about $27 million (including fuel savings) annually by the time the program is fully implemented. The emission benefits of this program are projected to be approximately 55,000 tons of HC+NO

annually by the time the program is fully implemented.

Finally, Sections VIII and IX contain information about public participation and various administrative requirements.

The remainder of this section summarizes the new requirements and provides some background and context for the final rule.

C. What Requirements Are We Adopting?

In general, we are harmonizing the federal motorcycle exhaust emission standards with those of the state of California, but on a delayed schedule relative to implementation in California and with some additional provisions that provide additional flexibility in meeting the standards. The process by which motorcycle manufacturers certify their motorcycles to the exhaust emission standards, including the test procedures, the driving cycle, and other elements of the federal program, are generally unchanged. We are also adopting exhaust emission standards for previously unregulated motorcycles with engines that are less than 50cc in displacement. In addition, we are adopting standards that will require the use of low permeability fuel tanks and fuel hoses on all motorcycles.

1. Class I and II Motorcycles

We are adopting a new exhaust emission standard for Class I and Class II motorcycles of 1.0 g/km HC, to replace the current federal HC standard of 5.0 g/km. This standard will become effective starting with the 2006 model year. Class I and II motorcycles have been meeting a standard of 1.0 g/km HC in California since 1982, and by 2006 the European versions of these motorcycles will be meeting HC and NO

standards that when combined are below 1.0 g/km.

We are also finalizing an optional HC+NO

standard of 1.4 g/km, which will be required for manufacturers who decide to take advantage of provisions that allow the transfer of emission credits and averaging of Class I and II engine families. Class I and II motorcycles represent about 5-10 percent of annual U.S. motorcycle sales. Class I and II motorcycles will also have to meet new requirements regarding low permeation fuel tanks and fuel hoses.

California standards are met using a test procedure identical to EPA's, whereas compliance with European standards is determined using a different test procedure.

We are also adopting a new definition of a Class I motorcycle which includes motorcycles with engine displacements of less than 50cc. These motorcycles—which are powered mostly by two-stroke engines currently—have not been subject to EPA emission regulations until now. We are finalizing a useful life for the under 50cc category of 5 years or 6,000 km, whichever first occurs. We are also revising the test procedure for this unique category of Class I motorcycles to ensure that these small motorcycles are tested appropriately.

2. Class III Motorcycles

We are adopting new exhaust emission standards for Class III motorcycles. Class III motorcycles represent more than 90 percent of annual U.S. sales. These standards, which can be met on a corporate-average basis, are identical to the standards of the California program. Specifically, we are adopting a “Tier-1” standard of 1.4 g/km HC+NO

starting in the 2006 model year, and a “Tier-2” standard of 0.8 g/km starting in the 2010 model year. Because both HC and NO

are ozone precursors, this new standard will better reduce ozone than an HC-only standard. Implementation on a nationwide basis will take place starting two model years after implementation of identical exhaust emission standards in California, ensuring that manufacturers have adequate lead time to plan for these new standards and to have full product lines available for sale. The federal CO standard of 12.0 g/km is unchanged by this final rule. The process by which manufacturers certify their motorcycles, the test procedures, the driving cycle, and other elements of the federal program remain unchanged. Class III motorcycles will also have to meet new requirements regarding low permeation fuel tanks and fuel hoses.

D. Putting This Action Into Perspective

Federal standards for highway motorcycles were first established in the 1978 model year (see 42 FR 1126, Jan. 5, 1977). Interim standards were effective for the 1978 and 1979 model years, and final standards took effect with the 1980 model year. The interim standards ranged from 5.0 to 14.0 g/km HC depending on engine displacement, while the interim CO standard of 17.0 g/km applied to all motorcycles. The standards and requirements effective for 1980 and later model year motorcycles, which do not include NO

emission standards, currently remain unchanged from when they were established 25 years ago. Crankcase emissions from motorcycles have also been prohibited since 1980. The level of technology required to meet these standards is widely considered to be comparable to the pre-catalyst technology in the automobile. These standards, which resulted in the phase-out of two-stroke engines for highway motorcycles above 50cc displacement, achieved significant reductions in emissions. There are no current federal standards for evaporative emissions from motorcycles. The current federal exhaust emission standards are shown in Table I.D-1.

Table I.D-1.—Current Federal Exhaust Emission Standards for Motorcycles

Class

Engine size

HC (g/km)

CO (g/km)

Useful life (km)

50-169

5.0

12.0

12,000

170-279

5.0

12.0

18,000

III

>279

5.0

12.0

30,000

Notes:

“Useful life” is the period over which the manufacturer must demonstrate compliance with emission standards. It is unrelated to how long a consumer can keep or ride a motorcycle.

However, it is clear that the impact of the current federal standards on motorcycle emission control was fully realized by the end of the 1980's, and that international and other efforts have been the driving factor in more recent technology development for motorcycle emissions control. In the past two decades, other actions in Europe, Asia, and California have caused motorcycle emission controls to continue to advance, despite the static U.S. emission standards in that same time period. In fact, most manufacturers elect to certify many of their motorcycles to the California standards (described below in section I.D.2) and market them nationwide. This practice has resulted in the average certification levels shown in Table I.D-2.

Table I.D-2.—Average Certification Levels for 2003 Model Year Motorcycles

Class

Engine size

HC (g/km)

CO (g/km)

50-169

1.3

7.2

170-279

0.9

7.2

III

>279

0.9

6.7

Note:

Manufacturers typically certify at levels that provide them with sufficient “headroom” between the actual certification level and the standard. This “headroom” is often 30-50% of the standard, as can be seen in the CO levels in this table which compare to a standard of 12 g/km.

1. New Federal Emission Standards for Recreational Vehicles

On November 8, 2002, we adopted new standards for all-terrain vehicles (ATVs), snowmobiles, and off-highway motorcycles.

These standards resulted from requirements in the Clean Air Act regarding all nonroad vehicles. In light of the requirements in the Act and our subsequent action to control emissions from off-road motorcycle and ATV emissions, we felt it both necessary and a matter of common sense to initiate an action to review and update the two-decade-old highway motorcycle emission standards. Table I.D-3 shows the emission standards that apply to recreational vehicles.

See 67 FR 68241 (November 8, 2002). The final rule also contained new standards for large spark-ignition engines such as those used in forklifts and airport ground-service equipment and recreational marine diesel engines.

Compliance with the off-highway motorcycle and ATV standards will be determined using the same test cycle that is currently used for highway motorcycles. Therefore the standards are directly comparable. The current federal highway motorcycle HC standard of 5.0 g/km appears even more misaligned with the current state of emission control technology when compared to the standards that their off-highway cousins will be meeting in the next few years. Today's action rectifies this imbalance in motorcycle and ATV emission standards.

Table I.D-3.—Recreational Vehicle Exhaust Emission Standards

Vehicle

Model year

Emission standards

HC g/kW-hr

CO g/kW-hr

Phase-in

Snowmobile

2006

100

275

50%

2007 through 2009

100

275

100%

2010 -option 1

200

2010 -option 2

275

HC+NO

g/km

Off-highway

2006

2.0

25.0

50%

Motorcycle

2007 and later

2.0

25.0

100%

ATV

2006

1.5

35.0

50%

2007 and later

1.5

35.0

100%

2. California Emission Standards for Highway Motorcycles

Motorcycle exhaust emission standards in California were originally identical to the federal standards that took effect in 1980. The definitions of motorcycle classes used by California ARB continue to be identical to the federal definitions. However, California ARB has revised its standards several times in bringing them to their current levels (see Table I.D-4). In the 1982

model year the standards were modified to tighten the HC standard from 5.0 g/km to 1.0 or 1.4 g/km, depending on engine displacement. California adopted an evaporative emission standard of 2.0 g/test for all three motorcycle classes for 1983 and later model year motorcycles. California later amended the regulations for 1988 and later model year motorcycles to further lower emissions and to make the compliance program more flexible for manufacturers. The 1988 and later standards could be met on a corporate-average basis, and the Class III motorcycles were split into two separate categories: 280 cc to 699 cc and 700 cc and greater. These are the standards that apply in California now. Like the federal standards, there are currently no limits on NO

emissions for highway motorcycles in California. Under the corporate-average scheme, no individual engine family is allowed to exceed a cap of 2.5 g/km HC. Like the federal program, California also prohibits crankcase emissions. Current California exhaust emission standards are shown in Table I.D-4.

Table I.D-4.—Current California Highway Motorcycle Exhaust Emission Standards

Class

Engine size (cc)

HC (g/km)

CO (g/km)

I & II

50-279

1.0

12.0

III

280-699

1.0

12.0

III

700 and above

1.4

12.0

In November 1999, the California ARB adopted new exhaust emission standards for Class III motorcycles that would take effect in two phases—Tier 1 standards starting with the 2004 model year, followed by Tier 2 standards starting with the 2008 model year (see Table I.D-5). Existing California standards for Class I and Class II motorcycles (see Table I.D-4), which have been in place since 1982, remain unchanged, as does their evaporative emissions standard. As with the current standards in California, manufacturers will be able to meet the requirements on a corporate-average basis. Perhaps most significantly, California ARB's Tier 1 and Tier 2 standards control NO

emissions for the first time by establishing a combined HC+NO

standard. California ARB made no changes to the CO emission standard, which remains at 12.0 g/km, equivalent to the existing federal standard. In addition, California ARB is providing an incentive program to encourage the introduction of Tier 2 motorcycles before the 2008 model year. This incentive program allows the accumulation of emission credits that manufacturers can use to meet the 2008 standards. Like the federal program, these standards will also apply to dual-sport motorcycles.

Table I.D-5.—Tier 1 and Tier 2 California Class III Highway Motorcycle Exhaust Emission Standards

Model year

Engine displacement

HC + NO

(g/km)

2004 through 2007 (Tier 1)

280 cc and greater

1.4

12.0

2008 and subsequent (Tier 2)

280 cc and greater

0.8

12.0

California ARB also adopted a new definition of small-volume manufacturer that will take effect with the 2008 model year. Currently and through the 2003 model year, all manufacturers must meet the standards, regardless of production volume. Small-volume manufacturers, defined in California ARB's recent action as a manufacturer with California sales of combined Class I, Class II, and Class III motorcycles not greater than 300 units annually, do not have to meet the new standards until the 2008 model year, at which point the Tier 1 standard applies.

3. European Union and Other International Actions

The European Union (EU) has established a new phase of motorcycle standards, which took effect in 2003, and has recently finalized a second phase that will start in 2006. The 2003 European standards are more stringent than the existing federal standards, and, with the exception of the CO standard, are roughly comparable to the California Tier 1 standards taking effect in 2004. The 2003 standards would require emissions to be below the values shown in Table I.D-6, as measured over the European ECE-40 test cycle.

The standards in Table I.D-6 apply to motorcycles of less than 50cc (

e.g.

, scooters and mopeds) only if the motorcycle can exceed 45 kilometers per hour (28 miles per hour). Starting in 2002 motorcycles of less than 50cc that cannot exceed 45 kilometers per hour (28 miles per hour) are subject to a new HC+NO

standard of 1.2 grams per kilometer and a CO standard of 1.0 gram per kilometer.

The ECE-40 cycle is used by several countries around the world for motorcycle emission testing. It has its origins in passenger car driving, being derived from the European ECE-15 passenger car cycle. The speed-time trace is simply a combination of straight lines, resulting in a “modal” cycle, rather than the transient nature of the U.S. Federal Test Procedure (FTP).

Table I.D-6.—European Union 2003 Motorcycle Exhaust Emission Standards for Motorcycles >150cc

(g/km)

1.0

5.5

0.3

New standards that would apply starting in 2006, along with a revised test cycle (as an interim cycle to bridge between the current EU cycle and a possible WMTC cycle in the future) have been recently finalized by the EU. Setting aside the difference in test cycles, the 2006 EU HC and NO

standards are roughly comparable to and perhaps somewhat more stringent than the California Tier 2 motorcycle standards effective in 2008. The 2006 EU standards are shown in Table I.D-7.

Table I.D-7.—European Union 2006 Motorcycle Exhaust Emission Standards for Motorcycles >150cc

(g/km)

0.3

2.0

0.15

Many other nations around the world, particularly in South Asia where two-stroke small displacement motorcycles can be a majority of the vehicle population, have also recently improved their emission standards or are planning to do so in the next several years. For example, Taiwan has adopted an HC+NO

standard of 1.0 gram per kilometer for all two-strokes starting in 2003 (as tested on the European ECE-40 test cycle). (Four-stroke motorcycle engines will have to meet at standard of 2.0 grams per kilometer.) India has proposed a standard for all motorcycles of 1.3 grams per kilometer HC+NO

in 2003 and 1.0 grams per kilometer HC+NO

in 2005 (as tested on the Indian Drive Cycle, or IDC).

China has adopted the 2003 European standards described above, implementing them in 2004, a year later than Europe.

The IDC, although not a transient cycle like the FTP, appears to be the only cycle currently in use that is based on actual measurements of motorcycles in use. Although the FTP is based on real-world driving of passenger cars and not motorcycles, it is reasonable to argue that the two types of vehicles are driven similarly.

E. Statutory Authority

Section 202(a)(1) and (2) of the Clean Air Act authorizes EPA to promulgate, and from time to time revise, standards applicable to emissions of any air pollutant from any class or classes of new motor vehicles that, in the Administrator's judgment cause or contribute to air pollution which in EPA's judgment may reasonably be anticipated to endanger public health or welfare. Such regulations shall apply for the useful life of the vehicle and “shall take effect after such period as the Administrator finds is necessary to permit the development and application of the requisite technology, giving appropriate consideration to the cost of compliance within such period.”

In particular, section 202(a)(3)(E) states that motorcycles shall be treated as heavy-duty vehicles unless “the Administrator promulgates regulations under subsection (a) of this section applying standards applicable to the emission of air pollutants from motorcycles as a separate class or category. In any case in which such standards are promulgated for such emissions as a separate class or category, the Administrator, in promulgating such standards, shall consider the need to achieve equivalency of emission reductions between motorcycles and other motor vehicles to the maximum extent practicable.”

EPA's initial standards regulating motorcycles were promulgated on December 23, 1976 (42 FR 1122). In that final rule EPA made the finding that highway motorcycles were a contributor to air pollution and that control of their emissions is necessary to meet the National Ambient Air Quality Standards. The air quality analyses conducted for this final rule (see the Final Regulatory Support Document) continue to support this conclusion. The standards promulgated in the 1976 rule and in this final rule treat motorcycles as a separate class of motor vehicle, and thus are governed by the language in section 202(a)(1) and (2) and 202(a)(3)(E). In promulgating these standards, EPA has considered the need to achieve equivalency in emission reduction between motorcycles and other motor vehicles (see Section 4.1 of the Final Regulatory Support Document).

F. Modification, Customization and Personalization of Motorcycles

Many motorcycle owners personalize their motorcycles in a variety of ways. This is one of the aspects of motorcycle ownership that is appealing to a large number of motorcycle owners, and they take their freedom to customize their bikes very seriously. However, there are some forms of customization that are not legal under the provisions of Clean Air Act section 203(a), which states that it is illegal:

for any person to remove or render inoperative any device or element of design installed on or in a motor vehicle or motor vehicle engine in compliance with regulations under this title prior to its sale and delivery to the ultimate purchaser or * * * after such sale and delivery to the ultimate purchaser.* * *

for any person to manufacture or sell * * * or install, any part or component intended for use with * * * any motor vehicle * * * where a principal effect of the part or component is to bypass, defeat, or render inoperative any device or element of design installed on or in a motor vehicle * * * in compliance with regulations under this title, and where the person knows or should know that such part or component is being offered for sale or installed for such use or put to such use. * * *

In other words, under current law, owners of motor vehicles

cannot legally make modifications that remove, bypass, or disable emission-control devices installed by the manufacturer.

It is also illegal for part manufacturers and dealers to manufacture, sell or install a part or component that the manufacturer or dealer knows or should know will be sold or used in a manner that defeats the emissions control system.

A motorcycle is a “motor vehicle” as defined under section 216 of the Clean Air Act, which states that “[t]he term “motor vehicle” means any self-propelled vehicle designed for transporting persons or property on a street or highway.”

See

Mobile Source Enforcement Memorandum No. 1A, Interim Tampering Enforcement Policy, Office of Enforcement and General Council, June 25, 1974 (Docket A-2000-01; document IV-A-27). (

http://www.epa.gov/oeca/ore/aed/comp/hcomp.html

)

We use the term “tampering” to refer specifically to actions that are illegal under Clean Air Act section 203; the term, and the prohibition, do not apply generally to the wide range of actions that a motorcycle enthusiast can take to personalize his or her motorcycle, but only to actions that remove or disable emission control devices or cause the emissions to exceed the standards. We know, from anecdotal reports and from some data collected from in-use motorcycles, that a portion of the motorcycle riding population has removed, replaced, or modified the original equipment on their motorcycles. This customization can include changes that can be detrimental (or, in some cases, possibly beneficial) to the motorcycle's emission levels. The NPRM sought comments and data that could better help us understand the nature of the issue, such that our final rule decisions could be made with the best understanding possible of current consumer practices. We did not propose to revise the existing tampering restrictions or to prohibit many of the things that motorcycle owners are now doing legally.

The new emission standards that we are adopting do not change this “tampering” prohibition, which has been in the Clean Air Act for more than 20 years. Part manufacturers are still free to make parts, dealers are free to sell and install parts, and owners are free to customize their motorcycles in any way, as long as they do not disable emission controls or cause the motorcycle to exceed the emission standards. Owners are also free to perform routine maintenance on their motorcycles to restore or maintain the motorcycle engine and related components in their original condition and configuration.

G. Future Actions

1. 2006 Technology Progress Review

The California ARB has indicated plans for a technology progress review, to take place in 2006, to evaluate manufacturers' progress in meeting the Tier 2 standards. Specifically, California ARB documents state that the purpose of the 2006 review would be to “* * * evaluate the success, cost, and consumer acceptance of engine modifications employed to meet Tier-1 * * *” and to “ * * * review and discuss manufacturers’ efforts to meet Tier-2 * * * ”

As part of that review, the California ARB has suggested they may reevaluate whether the Tier 2 standard should be applied to small-volume manufacturers in the future.

We plan to participate in that review and work with the California ARB and others. We would intend to make any appropriate adjustments to the Tier 2 standards or implementation schedule if our review leads to the conclusion that changes are warranted.

State of California Air Resources Board, October 23, 1998 “Proposed Amendments to the California On-Road Motorcycle Regulation” Staff Report: Initial Statement of Reasons (Docket A-2000-01; document II-D-12).

State of California Air Resources Board, “Final Statement of Reasons for Rulemaking: Proposed Amendments to the California On-Road Motorcycle Regulation.”

In the context of the 2006 progress review we will evaluate and possibly propose regulatory revisions with regard to a number of issues that are discussed in this final rule. In particular, we intend to pursue development of a program that would apply emission standards to motorcycle engine manufacturers. Small-volume manufacturers may be the primary consumers of motorcycle engines built by others, since they generally do not have the physical or technical resources to develop, test, and manufacture their own engines. Although these small manufacturers are provided with a substantial level of flexibility in the current program, some additional flexibility may be warranted in the future, especially with regard to very small manufacturers producing fewer than 100 motorcycles per year. In evaluating any potential future actions, we intend to carefully consider the potential impacts on the small segment of the motorcycle industry represented by the smallest manufacturers.

It is our view that a program could be structured such that small volume motorcycle manufacturers could purchase certified engines directly from an engine manufacturer. We believe that such a program could be structured such that it is both fair to the engine manufacturers and beneficial to small volume motorcycle manufacturers. Under one possible approach, small volume motorcycle manufacturers could choose to use certified engines and to accept the calibration or configuration of a certified engine that they purchase for use in their motorcycles. Small volume manufacturers would not be required to use certified engines, but if they chose either to use uncertified engines or to change the calibration or configuration of the certified engines they use, then they would have to independently certify their motorcycles to the applicable emission standards.

In the context of the 2006 review we may also evaluate additional evaporative emission requirements, more stringent CO standards, an HC+NO

standard for Class I and II motorcycles, and revisions to the useful life definitions. Further action on these or any other items would depend on an evaluation of appropriate criteria, including but not necessarily limited to costs and feasibility. These items, including the engine program, could be proposed with the world harmonized motorcycle test cycle discussed below if the timing is appropriate, or in an independent action if the timing is not appropriate.

2. Globally Harmonized Motorcycle Test Cycle

In the NPRM we noted the effort underway under the auspices of the United Nations/Economic Commission for Europe (UN/ECE) to develop a global harmonized world motorcycle test cycle (WMTC), and requested comment on adopting such a test cycle in the future. The United States is also a participating member of UN/ECE. The objective of the WMTC project is to develop a scientifically supported test cycle that accurately represents the in-use driving characteristics of highway motorcycles, and that could ultimately be integrated into the requirements of nations around the world. The advantages of such a test cycle are numerous. First, the industry could have a single test cycle to meet emission standards in many countries (the process recognizes that nations will have differing emission standards due the varying air-pollution concerns). Second, the test cycle could potentially be better than the existing FTP in that it is expected to better represent how a wide range of riders drive their motorcycles, which could ultimately result in further emission reductions.

At this time we are not adopting any modifications to the highway motorcycle test cycle. We continue to be involved in the WMTC process and are hopeful that a test cycle meeting the stated objectives can be agreed on by the international participants, including the United States. Although a draft test cycle has been developed, some issues remain unresolved and it will likely be some time before a new cycle can be issued as a global technical regulation under the process established by a 1998 international agreement. Under that process, if a test cycle is brought to a vote and the United States votes in the affirmative, we will then be committed to initiating a rulemaking that may lead to an action to adopt the new test cycle. If the timing is appropriate this action could include proposals relating to the 2006 technology review discussed above.

II. Why Is EPA Taking This Action?

This final rule establishes revised standards for highway motorcycles. The current emission standards for these vehicles were set in 1978 and are based on 1970-era emission control technology. We are adopting new HC and NO

standards that reflect the application of more advanced emission control technology. These standards are harmonized with California's highway motorcycle emission standards, but on a delayed schedule relative to implementation in California and with some additional provisions that provide additional flexibility in meeting the standards. We are also finalizing new federal emission standards for highway motorcycles under 50cc that are currently uncontrolled. Finally, we are adopting standards to control permeation evaporative emissions from the fuel tanks and fuel hoses on highway motorcycles.

As described below and in the Final Regulatory Support Document, these standards will help address the contribution of these engines to air pollution that causes public health and welfare problems. HC and NO

emissions from highway motorcycles contribute to ambient concentrations of ozone. They also add to fine particle levels and contribute to visibility impairment. The standards we are adopting, which are expected to result in about a 60 percent reduction in HC and NO

emissions in 2020, will help reduce these harmful emissions. They will also reduce personal exposure for people who operate, who work with, or are otherwise in close proximity to these vehicles. This is important because, in addition to the health effects associated with exposure to ozone and fine PM, many types of hydrocarbons are also air toxics.

Based on the most recent data available for this rule (1999-2001),

ozone and PM air quality problems are widespread in the United States. There are about 111 million people living in counties with monitored concentrations exceeding the 8-hour ozone NAAQS, and over 65 million people living in counties with monitored PM

2.5

levels exceeding the PM

2.5

NAAQS. This emission control program is another component of the effort by federal, state and local governments to reduce the health related impacts of air pollution and to reach attainment of the National Ambient Air Quality Standard (NAAQS) for ozone and particulate matter as well as to improve other environmental conditions such as atmospheric visibility.

A. What Are The Health and Welfare Effects of Highway Motorcycle Emissions?

Highway motorcycles generate emissions that contribute to ozone formation and ambient levels of PM and air toxics. This section summarizes the general health effects of these pollutants. National inventory estimates are set out in Section II.B, and estimates of the expected impact of these programs are described in Section VII. Interested readers are encouraged to refer to the Regulatory Support Document for this rule for more in-depth discussions.

1. Health and Welfare Effects Associated With Ground Level Ozone and Its Precursors

a. Health and Welfare Effects

Highway motorcycles contribute to ambient ozone levels through their HC and NO

emissions. Volatile organic compounds (VOC) and NO

are precursors in the photochemical reaction which forms tropospheric ozone. Ground-level ozone, the main ingredient in smog, is formed by complex chemical reactions of VOCs and NO

in the presence of heat and sunlight. Hydrocarbons are a set of compounds that are very similar to, but slightly different from, VOCs, and to reduce mobile-source VOC levels we set maximum limits for HC emissions.

For more information about VOC and HC,

see

U.S. EPA (1997), Conversion Factors for Hydrocarbon Emission Components, Report No. NR-002. A copy of this document is available in Docket A-2000-02, Document IV-A-26.

Ozone can irritate the respiratory system, causing coughing, throat irritation, and/or uncomfortable sensation in the chest.

13 14

Ozone can reduce lung function and make it more difficult to breathe deeply, and breathing may become more rapid and shallow than normal, thereby limiting a person's normal activity. Ozone also can aggravate asthma, leading to more asthma attacks that require a doctor's attention and/or the use of additional medication. In addition, ozone can inflame and damage the lining of the lungs, which may lead to permanent changes in lung tissue, irreversible reductions in lung function, and a lower quality of life if the inflammation occurs repeatedly over a long time period (months, years, a lifetime). People who are of particular concern with respect to ozone exposures include children and adults who are active outdoors. Others particularly susceptible to ozone effects are people with respiratory disease, such as asthma, and people with unusual sensitivity to ozone, and children. Beyond its human health effects, ozone has been shown to injure plants, which has the effect of reducing crop yields and reducing productivity in forest ecosystems.

15 16

U.S. EPA (1996). Air Quality Criteria for Ozone and Related Photochemical Oxidants, EPA/600/P-93/004aF. Docket No. A-99-06. Document Nos. II-A-15 to 17. More information on health effects of ozone is also available at

http:/www.epa.gov/ttn/naaqs/standards/ozone/s.03.index.html.

U.S. EPA. (1996). Review of National Ambient Air Quality Standards for Ozone, Assessment of Scientific and Technical Information, OAQPS Staff Paper, EPA-452/R-96-007. Docket No. A-99-06. Document No. II-A-22.

http:/www.epa.gov/ttn/naaqs/standards/ozone/s.03.index.html.

The 8-hour ozone standard, established by EPA in 1997, is based on well-documented science demonstrating that more people are experiencing adverse health effects at lower levels of exertion, over longer periods, and at lower ozone concentrations than addressed by the one-hour ozone standard.

The 8-hour standard addresses ozone exposures of concern for the general population and populations most at risk, including children active outdoors, outdoor workers, and individuals with pre-existing respiratory disease, such as asthma.

See,

e.g.

, 62 FR 38861-62, July 18, 1997.

There has been new research that suggests additional serious health effects beyond those that were known when the 8-hour ozone health standard was set. Since 1997, over 1,700 new health and welfare studies relating to ozone have been published in peer-reviewed journals.

Many of these studies investigate the impact of ozone exposure on such health effects as changes in lung structure and biochemistry, inflammation of the lungs, exacerbation and causation of asthma, respiratory illness-related school absence, hospital and emergency room visits for asthma and other respiratory causes, and premature mortality. EPA is currently in the process of evaluating these and other studies as part of the ongoing review of the air quality criteria and NAAQS for ozone. A revised Air Quality Criteria Document for Ozone and Other Photochemical Oxidants will be prepared in consultation with EPA's Clean Air Science Advisory Committee (CASAC). Key new health information falls into four general areas: development of new-onset asthma, hospital admissions for young children, school absence rate, and premature mortality. In all, the new studies that have become available since the 8-hour ozone standard was adopted in 1997 continue to demonstrate the harmful effects of ozone on public health and the need for areas with high ozone levels to attain and maintain the NAAQS.

New Ozone Health and Environmental Effects References, Published Since Completion of the Previous Ozone AQCD, National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (7/2002) Docket No. A-2001-28, Document II-A-79.

In addition to these health effects, HC emissions contain several air toxics that can also have adverse impacts on human health. The health effects of air toxics are briefly described below and discussed in more detail in the final Regulatory Support Document for this rule.

Ozone and its precursors also have welfare effects. Ozone has been shown to injure plants, which has the effect of reducing crop yields, reducing productivity in forests and other ecosystems. Ozone also attacks certain materials such as rubbers and plastics. Other environmental effects, such as acid deposition and eutrophication, are related to ozone precursors, such as NO

. Acid deposition, or acid rain as it is commonly known, occurs when SO2 and NO

react in the atmosphere with water, oxygen, and oxidants to form various acidic compounds that later fall to earth in the form of precipitation or dry deposition of acidic particles.

Acid rain contributes to damage of trees at high elevations and in extreme cases

may cause lakes and streams to become so acidic that they cannot support aquatic life. In addition, acid deposition accelerates the decay of building materials and paints, including irreplaceable buildings, statues, and sculptures that are part of our nation's cultural heritage. To reduce damage to automotive paint caused by acid rain and acidic dry deposition, some manufacturers use acid-resistant paints, at an average cost of $5 per vehicle—a total of $80-85 million per year when applied to all new cars and trucks sold in the U.S.

Much of the information in this subsection was excerpted from the EPA document, Human Health Benefits from Sulfate Reduction, written under Title IV of the 1990 Clean Air Act Amendments, U.S. EPA, Office of Air and Radiation, Acid Rain Division, Washington, DC 20460, November 1995. Available in Docket A-2000-01, Document No. II-A-32.

Eutrophication is the accelerated production of organic matter, particularly algae, in a water body. This increased growth can cause numerous adverse ecological effects and economic impacts, including nuisance algal blooms, dieback of underwater plants due to reduced light penetration, and toxic plankton blooms. Algal and plankton blooms can also reduce the level of dissolved oxygen, which can also adversely affect fish and shellfish populations. Deposition of nitrogen from on-highway motorcycle engines contributes to elevated nitrogen levels in waterbodies.

b. Current and Projected Ozone Levels

Ground level ozone today remains a pervasive pollution problem in the United States. In 2003, 114 million people (2000 census) lived in 53 areas designated nonattainment under the 1-hour ozone NAAQS.

This sharp decline from the 101 nonattainment areas originally identified under the Clean Air Act Amendments of 1990 demonstrates the effectiveness of the last decade's worth of emission-control programs. However, elevated ozone concentrations remain a serious public health concern throughout the nation. Unhealthy ozone concentrations exceeding the level of the 8-hour standard (

i.e.

, not requisite to protect the public health with an adequate margin of safety) occur over wide geographic areas, including most of the nation's major population centers. These monitored areas include much of the eastern half of the U.S. and large areas of California.

“One-hour Ozone and PM 10 Nonattainment Status and Air Quality Data Update,” Memorandum from Patricia Koman to Docket A-2000-2, August 11, 2003, Docket A-2000-02, Document IV-B-07. See also National Air Quality and Emissions Trends Report, 1999, EPA, 2001, at Table A-19. This document is available at

http://www.epa.gov/oar/aqtrnd99/.

The data from the Trends report are the most recent EPA air quality data that have been quality assured. A copy of this table can also be found in Docket No. A-2000-01, Document No. II-A-64.

According to data from 1999 to 2001, there are 291 counties where 111 million people live that measured values that violate the 8-hour ozone NAAQS.

An additional 37 million people live in 155 counties that have air quality measurements within 10 percent of the level of the standard. These areas, though currently not violating the standard, will also benefit from the additional emission reductions from this rule.

Additional counties may have levels above the NAAQS but do not currently have monitors. See U.S. EPA OAQPS Air Quality Data Analysis 1999-2001 Technical Support Document for Regulatory Actions (Docket A-2001-28; No. II-A-196).

Based on our air quality modeling performed for our recent Notice of Proposed Rulemaking proposing more stringent emission standards for nonroad diesel engines and the diesel fuel used in those engines (68 FR 28328, May 23, 2003), we anticipate that without emission reductions beyond those already required under promulgated regulations and approved SIPs, ozone nonattainment will likely persist into the future. With reductions from programs already in place, the number of counties violating the ozone 8-hour standard is expected to decrease in 2020 to 30 counties where 43 million people are projected to live. Thereafter, exposure to unhealthy levels of ozone is expected to begin to increase again. In 2030 the number of counties violating the ozone 8-hour NAAQS is projected to increase to 32 counties where 47 million people are projected to live. In addition, in 2030, 82 counties where 44 million people are projected to live will be within 10 percent of violating the ozone 8-hour NAAQS.

EPA is still developing the implementation process for bringing the nation's air into attainment with the ozone 8-hour NAAQS (

see

proposal, 68 FR 32702, June 2, 2003). The Act contains two sets of requirements for State plans implementing the national ozone air quality standards in nonattainment areas. Under subpart 1 of Title I, Part D, a State must demonstrate that nonattainment areas will attain the ozone 8-hour standard as expeditiously as practicable but no later than five years from the date that the area was designated nonattainment. However, based on the severity of the air quality problem and the availability and feasibility of control measures, the Administrator may extend the attainment date “for a period of no greater than 10 years from the date of designation as nonattainment.” Based on these provisions, we expect that most or all areas covered under subpart 1 will attain the ozone standard in the 2007 to 2014 time period. For areas covered under subpart 2, the maximum attainment dates provided under the Act range from 3 to 20 years after designation, depending on an area's classification. We anticipate that areas covered by subpart 2 will attain in the 2007 to 2024 time period.

EPA has proposed that States submit SIPs that address how areas will attain the 8-hour ozone standard within 3 years after nonattainment designation for moderate and above areas classified under subpart 2 and for some areas classified under subpart 1. EPA is also proposing that marginal areas and some areas designated under subpart 1 (

i.e.

, those with early attainment dates) will not be required to submit attainment demonstrations for the 8-hour ozone standard. We therefore anticipate that States will submit their attainment demonstration SIPs by April 2007.

Since the HC and NO

emission reductions expected from this final rule will go into effect during the period when areas will need to attain the 8-hour ozone NAAQS, the projected reductions in highway motorcycle emissions are expected to assist States in their effort to meet and maintain that standard.

2. Health and Welfare Effects Associated With Particulate Matter

a. Health and Welfare Effects

Highway motorcycles contribute to ambient particulate matter in two ways. First, they contribute through direct emissions of particulate matter in the exhaust. Second, they contribute through the indirect formation of PM (namely ammonium nitrate and organic carbonaceous PM

2.5

) in the atmosphere through their NO

and organic carbon emissions, especially HC. Carbonaceous PM

2.5

is a major portion of ambient PM

2.5

, especially in populous urban areas. The relative contribution of various chemical components to PM

2.5

varies by region of the country.

Particulate matter represents a broad class of chemically and physically diverse substances. It can be principally characterized as discrete particles that exist in the condensed (liquid or solid) phase spanning several orders of magnitude in size. All particles equal to and less than 10 microns are called PM

Fine particles can be generally defined as those particles with an aerodynamic diameter of 2.5 microns or less (also known as PM

2.5

), and coarse fraction particles are those particles with an aerodynamic diameter greater than 2.5 microns, but equal to or less than a nominal 10 microns. Fine particles can remain in the atmosphere for days to weeks and travel through the atmosphere hundreds to thousands of kilometers, while coarse particles deposit to the earth within minutes to

hours and within tens of kilometers from the emission source.

Scientific studies show ambient PM (which is attributable to a number of sources, including highway motorcycles) is associated with a series of adverse health effects. These health effects are discussed in detail in the EPA Criteria Document for PM as well as the draft updates of this document released in the past year.

U.S. EPA (1996). Air Quality Criteria for Particulate Matter—Volumes I, II, and III, EPA, Office of Research and Development. Report No. EPA/600/P-95/001a-cF. This material is available in Docket A-99-06, Documents IV-A-30 to 32. It is also available electronically at

http://www.epa.gov/ttn/oarpg/ticd.html.

U.S. EPA (2002). Air Quality Criteria for Particulate Matter—Volumes I and II (Third External Review Draft) This material is available in Docket A-2001-28, Documents II-A-98 and II-A-71. It is also available electronically at

http://cfpub.epa.gov/ncea/cfm/partmatt.cfm.

As described in these documents, health effects associated ambient PM have been indicated by epidemiologic studies showing associations between short-term exposure and increased hospital admissions for ischemic heart disease, heart failure, respiratory disease, including chronic obstructive pulmonary disease (COPD) and pneumonia. Short-term elevations in ambient PM have also been associated with increased cough, lower respiratory symptoms, and decrements in lung function. Short-term variations in ambient PM have also been associated with increases in total and cardiorespiratory daily mortality. Studies examining populations exposed to different levels of air pollution over a number of years, including the Harvard Six Cities Study and the American Cancer Society Study suggest an association between exposure to ambient PM

2.5

and premature mortality.

25 26

Two studies further analyzing the Harvard Six Cities Study's air quality data have also established a specific influence of mobile source-related PM

2.5

on daily mortality

and a concentration-response function for mobile source-associated PM

2.5

and daily mortality.

Another recent study in 14 U.S. cities examining the effect of PM

on daily hospital admissions for cardiovascular disease found that the effect of PM

was significantly greater in areas with a larger proportion of PM

coming from motor vehicles, indicating that PM

from these sources may have a greater effect on the toxicity of ambient PM

when compared with other sources.

Additional studies have associated changes in heart rate and/or heart rhythm in addition to changes in blood characteristics with exposure to ambient PM.

30 31

For additional information on health effects, see the Regulatory Support Document for this rule.

Dockery, DW; Pope, CA, III; Xu, X;

et al.

(1993). An association between air pollution and mortality in six U.S. cities. N Engl J Med 329:1753-1759.

Pope, CA, III; Thun, MJ; Namboordiri, MM;

et al.

(1995). Particulate air pollution as a predictor of mortality in a prospective study of U.S. adults. Am J Respir Crit Care Med 151:669-674.

Laden F; Neas LM; Dockery DW;

et al.

(2000). Association of fine particulate matter from different sources with daily mortality in six U.S. cities. Environ Health Perspect 108(10):941-947.

Schwartz J; Laden F; Zanobetti A. (2002). The concentration-response relation between PM(2.5) and daily deaths. Environ Health Perspect 110(10): 1025-1029.

Janssen NA; Schwartz J; Zanobetti A.;

et al.

(2002). Air conditioning and source-specific particles as modifiers of the effect of PM

on hospital admissions for heart and lung disease. Environ Health Perspect 110(1):43-49.

Pope CA III, Verrier RL, Lovett EG;

et al.

(1999). Heart rate variability associated with particulate air pollution. Am Heart J 138(5 Pt 1):890-899.

Magari SR, Hauser R, Schwartz J;

et al.

(2001). Association of heart rate variability with occupational and environmental exposure to particulate air pollution. Circulation 104(9):986-991.

The health effects of PM

are similar to those of PM

2.5

, since PM

includes all of PM

2.5

plus the coarse fraction from 2.5 to 10 micrometers in size. EPA also evaluates the health effects of PM between 2.5 and 10 micrometers in the draft revised Criteria Document. As discussed in the Diesel HAD and other studies, most diesel PM is smaller than 2.5 micrometers.

Both fine and coarse fraction particles can enter and deposit in the respiratory system.

U.S. EPA (1985). Size specific total particulate emission factor for mobile sources. EPA 460/3-85-005. Office of Mobile Sources, Ann Arbor, MI. A copy of this document is available in Docket A-2001-28, Document II-A-35.

PM also causes adverse impacts to the environment. Fine PM is the major cause of reduced visibility in parts of the United States, including many of our national parks. Other environmental impacts occur when particles deposit onto soils, plants, water or materials. For example, particles containing nitrogen and sulphur that deposit on to land or water bodies may change the nutrient balance and acidity of those environments. Finally, PM causes soiling and erosion damage to materials, including culturally important objects such as carved monuments and statues. It promotes and accelerates the corrosion of metals, degrades paints, and deteriorates building materials such as concrete and limestone.

b. Current and Projected Levels

There are NAAQS for both PM

and PM

2.5

. Violations of the annual PM

2.5

standard are much more widespread than are violations of the PM

standards. Each of these are discussed below.

i. PM

Levels. The current NAAQS for PM

were established in 1987. The primary (health-based) and secondary (public welfare based) standards for PM

include both short- and long-term NAAQS. The short-term (24 hour) standard of 150 ug/m

is not to be exceeded more than once per year on average over three years. The long-term standard specifies an expected annual arithmetic mean not to exceed 50 ug/m

averaged over three years.

Currently, 29 million people live in PM

nonattainment areas. There are currently 56 moderate PM

nonattainment areas with a total population of 6.6 million.

The attainment date for the initial moderate PM

nonattainment areas, designated by law on November 15, 1990, was December 31, 1994. Several additional PM

nonattainment areas were designated on January 21, 1994, and the attainment date for these areas was December 31, 2000. There are an additional 8 serious PM

nonattainment areas with a total affected population of 22.7 million. According to the Act, serious PM

nonattainment areas must attain the standards no later than 10 years after designation. The initial serious PM

nonattainment areas were designated January 18, 1994 and had an attainment date set by the Act of December 31, 2001. The Act provides that EPA may grant extensions of the serious area attainment dates of up to 5 years, provided that the area requesting the extension meets the requirements of Section 188(e) of the Act. Four serious PM

nonattainment areas (Phoenix, Arizona; Coachella Valley, South Coast (Los Angeles), and Owens Valley, California) have received extensions of the December 31, 2001 attainment date and thus have new attainment dates of December 31, 2006.

While all of these areas are expected to be in attainment before any significant emission reductions from this rule are expected to occur, these reductions will help these areas in maintaining the standards.

ii. PM

2.5

Levels. The NAAQS for PM

2.5

were established by EPA in 1997 (62 Fed. Reg., 38651, July 18, 1997). The short term (24-hour) standard is set at a level of 65 μg/m

based on the 98th percentile concentration averaged over three years. (This air quality statistic

compared to the standard is referred to as the “design value.”) The long-term standard specifies an expected annual arithmetic mean not to exceed 15 ug/m

averaged over three years.

“One-hour Ozone and PM

Nonattainment Status and Air Quality Data Update,” Memorandum from Patricia Koman to Docket A-2000-2, August 11, 2003, Docket A-2000-02, Document IV-B-07.

EPA has also proposed to grant Las Vegas, Nevada, an extension until December 31, 2006.

High ambient levels of PM

2.5

are widespread throughout the country. Current PM

2.5

monitored values for 1999-2001, which cover counties having about 75 percent of the country's population, indicate that at least 65 million people in 129 counties live in areas where annual design values of ambient fine PM violate the PM

2.5

NAAQS. There are an additional 9 million people in 20 counties where levels above the NAAQS are being measured, although there are insufficient data at this time to calculate a design value in accordance with the standard and thus determine whether these areas are violating the PM

2.5

NAAQS. In total, this represents 37 percent of the counties and 64 percent of the population in the areas with monitors with levels above the NAAQS. Furthermore, an additional 11 million people live in 41 counties that have air quality measurements within 10 percent of the level of the standard, with complete data. These areas, although not currently violating the standard, will also benefit from the additional HC and NO

reductions from these motorcycle emission standards.

The air quality modeling performed for our recent Notice of Proposed Rulemaking proposing more stringent emission standards for nonroad diesel engines and the diesel fuel used in those engines (68 FR 28328, May 23, 2003) suggests that similar conditions are likely to continue to exist in the future in the absence of additional measures to reduce these emissions. For example, in 2020 based on emission controls currently adopted, we project that 66 million people will live in 79 counties with average PM

2.5

levels above 15 ug/m

. In 2030, the number of people projected to live in areas exceeding the PM

2.5

standard is expected to increase to 85 million in 107 counties. An additional 24 million people are projected to live in counties within 10 percent of the standard in 2020, which will decrease to 17 million people in 2030.

By reducing HC and NO

emissions from highway motorcycles, the standards we are finalizing will assist States as they implement local controls to reduce PM

2.5

levels and help ensure long term maintenance with the NAAQS.

3. Health Effects Associated With Air Toxics

In addition to the human health and welfare impacts described above, emissions from the engines covered by this rule also contain several Mobile Source Air Toxics, including benzene, 1,3-butadiene, formaldehyde, acetaldehyde, and acrolein.

The health effects of these air toxics are described in more detail in the Regulatory Support Document for this rule. Additional information can also be found in the Technical Support Document for our final Mobile Source Air Toxics rule.

EPA recently finalized a list of 21 Mobile Source Air Toxics, including VOCs, metals, and diesel particulate matter and diesel exhaust organic gases (collectively DPM+DEOG). 66 FR 17230, March 29, 2001. This material is available in Docket No. A-2000-01, Documents Nos. II-A-42 and II-A-30.

See our Mobile Source Air Toxics final rulemaking, 66 FR 17230, March 29, 2001, and the Technical Support Document for that rulemaking. Copies of these documents are available in Docket No. A-2000-01, Documents Nos. II-A-42 and II-A-30.

The hydrocarbon controls contained in this rule are expected to reduce exposure to air toxics and therefore may help reduce the impact of these engines on cancer and noncancer health effects.

B. What Is the Emission Inventory Contribution From Highway Motorcycles?

The highway motorcycles subject to the standards finalized today contribute to the national inventories of pollutants that are associated with the health and public welfare effects described in Section II.A. Emission estimates for highway motorcycles were developed using information on the certification levels of current motorcycles and information on motorcycle use provided by the motorcycle industry. A more detailed description of the highway motorcycle modeling and our estimation methodology can be found in the Chapter 6 of the Draft Regulatory Support Document.

In order to determine the relative contribution of highway motorcycles to overall emissions, we estimated the emissions from all sources. Overall emission inventory estimates for the years 1996 and 2020 are summarized in Tables II.B-1 through II.B-3 for VOC, NO

, and PM emissions, respectively.

The estimates shown for highway motorcycles are baseline estimates and do not account for the impact of the standards adopted today. These tables show the relative contributions of the different mobile-source categories to the overall national mobile-source inventory. Of the total emissions from mobile sources, highway motorcycles contribute about 0.6 percent, 0.1 percent, and less than 0.1 percent of VOC, NO

, and PM emissions, respectively, in the year 1996. The projections for 2020 for the highway motorcycles subject to the standards adopted today show that emissions from these categories are expected to increase over time if left uncontrolled. Projections indicate that motorcycles are expected to contribute 2.3 percent, 0.3 percent, and 0.1 percent of mobile source VOC, NO

, and PM emissions in the year 2020 if left uncontrolled. Population growth and the effects of other regulatory control programs are factored into these projections.

The inventories cited in Tables II.B-1 through II.B-3 were developed for the Nonroad Diesel Rulemaking. See 68 FR 28328, May 23, 2003. The inventories for recreational marine engines greater than 50 horsepower, nonroad spark-ignition engines greater than 25 horsepower, and recreation spark-ignition engines have been updated using the latest version of EPA's NONROAD model to account for the new standards adopted by EPA in late 2002. See 67 FR 68242, November 8, 2002.

Table II.B-1.—Annual VOC Baseline Emission Levels for Mobile and Other Source Categories

a,b,c

Category

1996

VOC short tons

% of mobile source

% of total

2020

VOC short tons

% of mobile source

% of total

Highway Motorcycles

47,368

0.6

0.3

86,520

2.2

0.6

Highway Light-duty

4,635,410

55.8

25.0

1,755,119

45.4

13.0

Highway Heavy-duty

608,607

7.3

3.3

226,641

5.9

1.7

Land-based Nonroad Diesel

221,403

2.7

1.2

96,855

2.5

0.7

Recreational Marine Diesel ≤50 hp

128

0.0

108

0.0

Recreational Marine Diesel >50 hp

1,199

0.0

1,531

0.0

Recreational Marine SI

804,488

9.7

4.3

380,891

9.9

2.8

Nonroad SI ≤25 hp

1,330,229

16.0

7.2

650,158

16.8

4.8

Nonroad SI >25hp

85,701

1.0

0.5

12,265

0.3

0.1

Recreational SI

308,285

3.7

1.7

339,098

8.8

2.5

Commercial Marine Diesel

31,545

0.4

0.2

37,290

1.0

0.3

Commercial Marine SI

960

0.0

998

0.0

Locomotive

48,381

0.6

0.3

36,546

0.9

0.3

Aircraft

176,394

2.1

1.0

239,654

6.2

1.8

Total Nonroad

3,008,713

1,795,394

Total Highway

5,291,385

2,068,280

Total Mobile Sources

8,300,098

100

3,863,674

100

Stationary Point and Area Sources

10,249,136

9,648,376

Total Man-Made Sources

18,549,234

13,512,050

Mobile Source Percent of Total

Notes:

These are 48-state inventories. They do not include Alaska and Hawaii.

The mobile source estimates include both exhaust and evaporative emissions.

Hydrocarbons (HC) are a set of compounds that are very similar to, but slightly different from, VOCs, and to reduce mobile source VOC levels we set maximum limits for HC emissions.

Table II.B-2.—Annual NO

Baseline Emission Levels for Mobile and Other Source Categories

Category

1996

short tons

% of mobile source

% of total

2020

short tons

% of mobile source

% of total

Highway Motorcycles

7,284

0.1

0.0

14,059

0.3

0.1

Highway Light-duty

4,427,634

33.8

18.0

1,264,342

25.0

8.4

Highway Heavy-duty

4,626,004

35.3

18.8

696,911

13.8

4.6

Land-based Nonroad Diesel

1,583,664

12.1

6.4

1,140,727

22.6

7.6

Recreational Marine Diesel ≤50 hp

523

0.0

682

0.0

Recreational Marine Diesel >50 hp

33,468

0.3

0.1

47,675

0.9

0.3

Recreational Marine SI

33,304

0.3

0.1

61,749

1.2

0.4

Nonroad SI ≤25 hp

63,584

0.5

0.3

100,119

2.0

0.7

Nonroad SI >25hp

273,099

2.1

1.1

43,322

0.9

0.3

Recreational SI

4,297

0.0

17,129

0.3

0.1

Commercial Marine Diesel

959,704

7.3

3.9

819,201

16.2

5.4

Commercial Marine SI

6,428

0.0

4,551

0.1

0.0

Locomotive

921,556

7.0

3.8

612,722

12.1

4.1

Aircraft

165,018

1.3

0.7

228,851

4.5

1.5

Total Nonroad

4,044,645

3,076,728

Total Highway

9,060,922

1,975,312

Total Mobile Sources

13,105,567

100

5,052,040

100

Stationary Point and Area Sources

11,449,752

10,050,213

Total Man-Made Sources

24,555,319

15,102,253

Mobile Source Percent of Total

Notes:

These are 48-state inventories. They do not include Alaska and Hawaii.

Table II.B-3.—Annual Direct PM-2.5 Baseline Emission Levels for Mobile and Other Source Categories

a,b

Category

1996

PM-2.5 short tons

% of mobile source

% of total

2020

PM-2.5 short tons

% of mobile source

% of total

Highway Motorcycles

184

0.0

434

0.1

0.0

Highway Light-duty

57,534

10.2

2.6

47,136

13.2

2.3

Highway Heavy-duty

172,965

30.7

7.8

24,806

7.0

1.2

Land-based Nonroad Diesel

176,510

31.3

8.0

124,334

34.9

6.0

Recreational Marine Diesel ≤50 hp

0.0

Recreational Marine Diesel >50 hp

815

0.1

0.0

1,162

0.3

0.1

Recreational Marine SI

35,147

6.2

1.6

26,110

7.3

1.3

Nonroad SI ≤25 hp

24,130

4.3

1.1

29,998

8.4

1.5

Nonroad SI >25hp

1,374

0.2

0.1

2,302

0.6

0.1

Recreational SI

7,968

1.4

0.4

9,963

2.8

0.5

Commercial Marine Diesel

36,367

6.5

1.6

41,365

11.6

2.0

Commercial Marine SI

1,370

0.2

0.1

1,326

0.4

0.1

Locomotive

20,937

3.7

0.9

16,727

4.7

0.8

Aircraft

27,891

5.0

1.3

30,024

8.4

1.5

Total Nonroad

332,571

283,381

Total Highway

230,683

72,376

Total Mobile Sources

563,254

100

355,757

100

Stationary Point and Area Sources

1,653,392

1,712,004

Total Man-Made Sources

2,216,646

2,067,761

Mobile Source Percent of Total

Notes:

These are 48-state inventories. They do not include Alaska and Hawaii.

Excludes natural and miscellaneous sources.

III. Which Vehicles and Engines Are Covered?

We are adopting new standards for new highway motorcycles, including those with engines with displacements of less than 50cc. These requirements apply to manufacturers of motorcycles. Companies that produce and sell motorcycle engines are not directly covered, unless such a company also manufactures motorcycles. Every company that manufactures motorcycles for introduction into commerce in the U.S., whether or not they also manufacture motorcycle engines, is covered by EPA regulations. Engine manufacturers will be indirectly required to design and build complying engines, because their customers (

e.g.

, motorcycle manufacturers that purchase their engines) will require engines that comply with emission standards.

In order to be defined as a highway motorcycle—and therefore covered by the new standards—a motorcycle must first be defined as a motor vehicle under the Clean Air Act and EPA regulations. EPA regulations then specify the characteristics that cause a motor vehicle to be defined as a highway motorcycle. EPA regulations also divide highway motorcycles into three “classes,” which are used to determine the specific compliance requirements applicable to a given motorcycle. This section explains the definitions and the motorcycle classes defined by EPA.

A. What Is a Highway Motorcycle?

To reach the conclusion that a two- or three-wheeled vehicle is a highway motorcycle (a motorcycle legal for use on public roads), the vehicle must first be defined as a “motor vehicle” under the Clean Air Act.

The Clean Air Act specifies that the term “motor vehicle,” as used in the Act, applies only to vehicles “designed for transporting persons or property on a street or highway” (CAA section 216). In addition, EPA has promulgated regulations, in 40 CFR 85.1703, that elaborate on the Act's definition of motor vehicles and set forth three criteria, which, if any one is met, would cause a vehicle to not be considered a motor vehicle under the regulations, and therefore not subject to requirements applicable to motor vehicles. These criteria are:

(1) The vehicle cannot exceed a maximum speed of 25 miles per hour over a level paved surface; or

(2) The vehicle lacks features customarily associated with safe and practical street or highway use, including such things as a reverse gear (except motorcycles), a differential, or safety features required by state and/or federal law; or

(3) The vehicle exhibits features which render its use on a street or highway unsafe, impractical, or highly unlikely, including tracked road contact means, an inordinate size, or features ordinarily associated with military combat or tactical vehicles such as armor and/or weaponry.

A vehicle that cannot be considered a motor vehicle under the statutory and regulatory definitions described above is generally considered under the Clean Air Act to be a “nonroad” vehicle. Mopeds and scooters that do not meet the definition of “motor vehicle” (

e.g.

, very small mopeds and scooters) because they can not exceed 25 miles per hour or because they meet some of the other criteria described above are considered nonroad recreational vehicles and are subject to the applicable emission standards for off-highway motorcycles.

Once it is determined that a vehicle is a “motor vehicle”, EPA regulations then determine which motor vehicles are highway motorcycles for the purposes of applying emission standards. Although motorcycles come in a variety of two- and three-wheeled configurations and styles, for the most part they are two-wheeled, self-powered vehicles. EPA regulations currently define a motorcycle as “any motor vehicle with a headlight, taillight, and stoplight and having: two wheels, or three wheels and a curb mass less than or equal to 793 kilograms (1749 pounds)” (See 40 CFR 86.402-98).

In the past, vehicles that would otherwise meet the definition of a motorcycle but with an engine displacement of less than 50cc (

e.g.

, small scooters and mopeds), have not been subject to any EPA emission standards. In this final rule we are, for the first time, applying emission standards to any highway motorcycle, regardless of displacement.

B. What Are Class I, Class II, and Class III Highway Motorcycles?

Both EPA and California regulations sub-divide highway motorcycles into classes based on engine displacement. These divisions have been consistent

between EPA and the California ARB for many years. However, we are adopting a revised definition for Class I motorcycles in order to apply the Class I emission standards to motorcycles with displacements of less than 50cc. The revised definition will take effect with the 2006 model year. Table V.A-1 shows how these classes are defined before and after implementation of new standards for motorcycles with engines of less than 50cc displacement.

Table III.B-1.—Motorcycle and Motorcycle Engine Classes

Motorcycle class

Engine displacement (cubic centimeters)

Through 2005 model year

2006 and later model years

Class I

50-169

0-169.

Class II

170-279

170-279.

Class III

280 and greater

280 and greater.

Highway motorcycles with engine displacements less than 50cc are mostly mopeds and motor scooters (“scooters,” or sometimes, “motorbikes”). These vehicles are generally powered by 49cc two-stroke engines, although four-stroke engines are becoming more popular. Honda, a major player in this market sector, will no longer be marketing any two-stroke street-use motorcycles as of the 2003 model year; everything, including their 49cc scooter, will be powered by a four-stroke engine.

All motorcycles currently certified to EPA emission standards are powered by four-stroke engines. Class I and II motorcycles, which make up less than ten percent of unit sales and only 24 out of 175 certified 2002 engine families, consist mostly of dual-sport motorcycles, scooters, and entry-level sport bikes and cruisers. Class III motorcycles represent 151 of the 175 certified 2002 engine families, and more than 90 percent of annual sales. Most Class III motorcycles are powered by relatively large engines, as demonstrated by an average displacement in the class of about 1100cc. Although there are some motorcycles that use eight-cylinder automotive engines and some on the horizon that may have displacements near 2300cc, the typical top-end displacement is around 1800cc.

IV. Exhaust Emission Standards and Test Procedures

We are adopting new exhaust emission standards for highway motorcycles. This section includes a description of the new standards and other important provisions. A discussion of the technological feasibility of the standards is in Section V of this document.

A. What Are the New Exhaust Emission Standards?

In general, we are harmonizing the federal exhaust emission standards for all classes of motorcycles with those of the California program, but on a delayed schedule relative to implementation in California. For Class I and Class II motorcycles this means meeting exhaust emission standards for HC and CO that have applied in California since 1982. Motorcycles with engine displacements of less than 50cc (previously unregulated) will be considered Class I motorcycles, and thus subject to the Class I standards. However, we have set a useful life of 6,000 km for under 50cc motorcycles. We are also adopting an optional HC+NO

standard for Class I and II motorcycles, which will be required of manufacturers wishing to average their emissions or transfer emission credits across classes. For Class III motorcycles, the standards will require compliance with two tiers of exhaust emission standards that California ARB has put in place for future model years. The existing federal CO standard of 12.0 g/km remains unchanged. The process by which manufacturers certify their motorcycles, the test procedures, the driving cycle, and other elements of the federal program also remain unchanged.

1. Class I and II Motorcycles

We are adopting the current California ARB Class I and II exhaust emission standards on a nationwide basis starting with the 2006 model year. These standards, which have been in place in California since 1982, are shown in Table IV.A-1. In recent years, motorcycles certified to the California standards have been sold nationwide, and there have been few, if any, motorcycles in those classes that are limited to 49-state sales due to their not being able to meet the California standards.

Table IV.A-1.—Final Class I and II Exhaust Emission Standards

Class and displacement (cc)

(g/km)

Useful life

I-A (0-49)

1.0

12.0

5 years/6,000 km

I-B (50-169)

1.0

12.0

5 years/12,000 km

II (170-279)

1.0

12.0

5 years/18,000 km.

Notes:

In order to distinguish the two segments within Class I that have differing useful life definitions, the regulatory text defines Class I-A (0-49cc) and Class I-B (50-169cc).

We are also redefining Class I motorcycles to include those motorcycles with engine displacements under 50cc; thus, these previously unregulated motorcycles will be subject to the Class I standards shown in Table IV.A-1. As described further in Section IV.C, certain Class I motorcycles with an engine displacement under 50cc will be tested on a driving cycle that is slightly modified in order to accommodate the lower speed and acceleration capabilities of these motorcycles relative to other Class I motorcycles.

For all Class I and II motorcycles we are also adopting an optional HC+NO

standard of 1.4 g/km. As of 2006 when new Class I and II standards become effective, the category of motorcycles under 50cc will be meeting an HC+NO

standard of 1.2 g/km in the EU, albeit on a different duty cycle. Also in 2006, motorcycles at or above 50cc but less than 150cc in the EU will be meeting an

HC standard of 0.8 g/km and a NO

standard of 0.15 g/km (combined HC+NO

of 0.95), and motorcycles over 150cc will be meeting standards that are even lower. In addition, an HC+NO

standard of 1.4 g/km is equivalent to the Class III standard that goes into effect in 2006. We believe that an HC+NO

standard is the only appropriate way to enable the transfer of credits across motorcycle classes in the finalized averaging program, and this optional standard should also be required of any manufacturer who wants to average Class I and II engine families (discussed in detail in Section IV.B).

We are providing a few years of lead time before these standards take effect for several reasons. First, the previously unregulated Class I category under 50cc will require some lead time to meet new standards. Second, we are allowing some averaging provisions that enable manufacturers to transfer Class III emission credits to Classes I and II, and these provisions will not be applicable until new Class III standards take effect in 2006. Third, although all Class I and II engine families in the 2002 model met these standards, that is not the case with the 2003 model year. This indicates to us that there may possibly be some models already under development in the context of the existing federal standard, and an abrupt transition to the new standard would create some difficulty in such cases. Given that the vast majority of Class I and II motorcycles do already meet the standards we are finalizing, it seems unreasonable to potentially disrupt the introduction and sale of a small number of motorcycles to advance the standards to an earlier date.

As we noted in the NPRM, the U.S. is a minor market for small motorcycles, scooters, and mopeds, especially those with engine displacements of under 50cc. Some manufacturers, such as Piaggio (maker of the Vespa scooters), may sell only a few thousand units in the U.S., but have worldwide sales of scooters that approach the magnitude of total U.S. motorcycle sales. We believe that an attempt to drive technology and emission limits for these vehicles beyond those that are applicable in the major small motorcycle and scooter markets could result in the outright withdrawal of some manufacturers' products from the U.S. market. These companies could choose to forego the small amount of U.S. sales rather than develop specific technologies to address U.S. requirements.

2. Class III Motorcycles

We are harmonizing the federal Class III motorcycle standards with the exhaust emission standards of the California program, as shown in Table IV.A-1. Specifically, we are adopting a Tier 1 standard of 1.4 g/km HC+NO

starting in the 2006 model year, and a Tier 2 standard of 0.8 g/km HC+NO

starting in the 2010 model year. Because both HC and NO

are ozone precursors, this new standard would better reduce ozone than an HC-only standard. Implementation on a nationwide basis will take place starting two model years after implementation of identical exhaust emission standards in California, ensuring that manufacturers have adequate lead time to plan for these new standards. As described in Section IV.B in further detail, these standards can be met on a corporate-average basis.

Table IV.A-1.—Final Class III Exhaust Emission Standards (g/km)

Model year

HC+NO

2006-2009

1.4

12.0

2010 and later

0.8

12.0

As noted earlier, California ARB plans a technology progress review in 2006 to evaluate manufacturers' progress in meeting the Class III Tier 2 standards. We plan to participate in that review and work with California ARB and others, intending to make any appropriate adjustments to the standards or implementation schedule if warranted.

B. Can I Average, Bank, or Trade Emission Credits?

To provide flexibility in meeting the standards, we are adopting an emission-credit program comparable to the existing California ARB regulations, but with additional flexibility relative to California ARB's program. The program consists of two parts. The first component, the averaging program, allows manufacturers to meet the standards on a fleet-average basis. The second component, the early credits programs, provides incentives for the early introduction of Class III motorcycles meeting the Tier 2 standards. We are not adopting any banking provisions beyond the early credits program, and are not adopting any form of emissions trading program. The emission-credit program is described in detail in the following paragraphs.

Under the averaging program, manufacturers are able to balance the certified emissions of their motorcycles so that the sales-weighted emissions level meets the applicable standard. This means that some engine families may have emissions below the standards, while others have emissions higher than the standards. For enforcement purposes, manufacturers are required to specify a certification limit, or “Family Emission Limit” (FEL) for each engine family. The FEL is the emission level that a particular engine family is certified as meeting and, in effect, become the standard for the individual family. The FEL may be above or below the applicable standard as long as the manufacturer's sales-weighted emissions level meets the applicable standard.

We proposed an averaging program for Class III motorcycles only, and requested comment on whether we should include Class I and II motorcycles in the averaging program. Based on comments, we are including Class I and II motorcycles in the averaging program with certain restrictions intended to address concerns about the relative stringency of the Class I and II standards relative to the Class III standards. We are creating two separate averaging sets, one for Class I and II motorcycles and one for Class III motorcycles. Averaging would be allowed without constraint within each of these two averaging sets. However, we are limiting the manner in which credits could be exchanged between the two averaging sets. Credits from Class III motorcycles could be used to offset debits from Class I and II motorcycles. These credits are calculated by multiplying the g/km emission level by the useful life (in km) to give total grams of credits. Therefore, there is no need to accommodate the engine size differences between the different motorcycle classes. However, given that the Class I and II standards are less stringent than the Class III standards, we are not allowing Class I and II credits to be used to offset debits from Class III motorcycles. This also addresses concerns expressed by some commenters that all manufacturers do not offer products in all classes, and allowing Class I and II credits to be used for Class III compliance would inherently disadvantage Class III-only manufacturers. Because the Class III standards are HC+NO

standards while the primary Class I and II standards are HC only, we will allow such cross class averaging only if the manufacturer uses the optional HC+NO

standards for Classes I and II. In addition, Class I and II motorcycles could be averaged together, but must be certified to the optional HC+NO

standards in order to participate in the averaging program. We believe that this is an appropriate approach for several reasons. California

does not currently offer an averaging program for Class I and II motorcycles. Therefore, the optional standard provides additional flexibility relative to the California program, and this flexibility allows the certification of motorcycles that are higher-emitting than those allowed in California. An averaging program with an HC-only standard would result in additional flexibility, but also in additional uncertainty regarding the overall impact on total emissions of ozone precursors. We have also established that in some recent model years all Class I and II motorcycles have been in compliance with the primary HC standard that we are adopting, which is not typically the sort of situation where additional flexibility is warranted or offered. However, we believe that additional flexibility can be offered in exchange for controlling NO

to reasonably achievable levels.

We believe that it is appropriate to retain our general historical approach to FEL caps by setting the Class III FEL cap at 5.0 g/km HC+NO

as proposed, primarily to allow flexibility in the transition to the new standards. While it is true that this approach will allow some motorcycle models which do not meet the California FEL cap of 2.5 g/km HC+NO

to be manufactured and sold outside of California, the number of models is quite small (less than ten of the 192 model year 2003 engine families certified as of March, 2003). However, we also believe that such an approach, while helping to ease the transition to the new standards, is not defensible for the long term. Thus, we are adopting an FEL cap of 2.5 g/km HC+NO

(the level of the California FEL cap) for Class III motorcycles to be effective with the implementation of the Tier 2 standards in the 2010 model year. Consistent with our approach to FEL caps for Class III motorcycles, we are adopting 5.0 g/km HC+NO

as an FEL cap for Class I and II motorcycles, to apply in the 2006 model year when the new standards and averaging program take effect for these motorcycles.

To encourage early compliance with the Tier 2 standards for Class III motorcycles, we are adopting an early credits program similar to the one in place in California, with timing adjusted due to the differing federal implementation schedule. We believe the incentives in this program will encourage manufacturers to introduce Tier 2 motorcycles nationwide earlier than required by the rule. In addition, we believe some manufacturers can reduce emissions even further than required by the Tier 2 standard, and we would like to encourage the early introduction of these very low-emission vehicles.

Under the early credits program, credits will be calculated based on the amount that a Class III motorcycle is below the Tier 2 standards. These credits are banked and can be used beginning with the 2010 model year. In order to provide incentives for the early introduction of even cleaner Tier 2 motorcycles, we are also adopting provisions to increase these early credits by a specific multiplier factor depending on how far below the Tier 2 standards a motorcycle is and how long before 2010 it is produced. These multipliers are shown in Table IV.B-1. Because we expect the Tier 2 technologies to become more widespread as 2010 approaches, the multipliers decrease linearly in value from 2006 until 2010, when the early compliance incentive will no longer have any value (

i.e.

, the multiplier has a value of 1.0) and the program will terminate.

Table IV.B-1.—Multipliers To Encourage Early Compliance With the Tier 2 Standard and Beyond

Model year sold

Multiplier (Y) for use in MY 2010 and later corporate averaging

Early tier 2

Certified at 0.4 g/km

HC+NO

2003 through 2006

1.5

3.0

2007

1.375

2.5

2008

1.250

2.0

2009

1.125

1.5

Notes:

Early Tier 2 motorcycles and motorcycles certified to 0.4 g/km are counted cumulatively toward the MY 2010 and later corporate average.

In 2010 and later model years the program becomes a basic averaging program, where each manufacturer has to meet the applicable HC+NO

standard on a fleet-average basis. See the regulations at § 86.449.

We are not adopting a required production line testing (PLT) program for highway motorcycles as part of this action. However, we are concerned about the integrity of post-certification changes to FELs in the absence of a PLT program which could be the source of data needed to justify a downward change in an FEL. Thus, we will not allow post-certification downward changes to FELs in the absence of supporting emission data. Further, a manufacturer must provide such data and seek advance approval from us for a downward FEL change. In addition, any such downward FEL change could not be inconsistent with the levels shown in existing certification data. These requirements only apply to downward FEL adjustments. We will not require such data or advance notice to justify upward adjustments to FELs. However, any upward adjustment to FELs must not cause a manufacturer's fleet to violate the relevant standard.

C. What Are the Applicable Test Procedures?

With the exception of the newly regulated category of motorcycles with engines of less than 50cc displacement, we are not making any changes to the motorcycle exhaust emission test procedures. We have noted the potential for a world harmonized test cycle—which would likely affect all highway motorcycle classes, and in fact would possibly redefine the classes—but international discussions regarding such a test cycle and associated standards are still likely two to three years away from being completed.

Class I motorcycles are currently provided with a less severe test cycle than Class II and III motorcycles. This test cycle is essentially the traditional FTP, but with lower top speeds and reduced acceleration rates relative to the FTP that is used for Class II and III motorcycles and other light-duty vehicles. The Class I FTP has a top speed of 58.7 km/hr (36.5 mph), whereas the Class II/III FTP has a top speed of 91.2 km/hr (56.7 mph). In the NPRM we requested comment on whether the existing Class I driving cycle was appropriate for the under 50cc category, and manufacturers of these motorcycles commented that it was not. The manufacturers (MIC and ACEM) noted that many of the machines in the under 50cc category have top speeds that are less than 36.5 mph, the highest speed of the current Class I test cycle. Based on these comments, we are adopting a modified version of the Class I driving cycle—supported by the manufacturers—that ensures that motorcycles under 50cc that have top speeds below 58.7 km/hr (36.5 mph) are tested within their operational limits.

Starting with the 2006 model year, the existing Class I driving cycle will be modified for motorcycles under 50cc with vehicle top speeds of less than 36.5 mph by adjusting each speed point of the driving cycle by the ratio of the top speed of the motorcycle to 36.5 mpg (the top speed of the existing Class I drive cycle). We are defining “vehicle top speed” in the regulations as the highest sustainable speed on a flat paved surface with a rider weighing 80 kg (176

lbs).

A motorcycle under 50cc with a top speed at or greater than 36.5 mph is required to be tested using the existing and unmodified Class I driving cycle.

Loaded vehicle mass, as defined in 40 CFR 86.402-78.

D. What Test Fuel Is Required for Emission Testing?

The specifications for gasoline to be used by the EPA and by manufacturers for emission testing can be found in 40 CFR 86.513-94. These regulations also specify that the fuel used for vehicle service accumulation shall be “representative of commercial fuels and engine lubricants which will be generally available through retail outlets.” During the last twenty years of regulation of motorcycle emissions, the fuel specifications for motorcycle testing have been essentially identical to those for automotive testing. However, on February 10, 2000, EPA published a final rule entitled “Tier 2 Motor Vehicle Emissions Standards and Gasoline Sulfur Control Requirements” (65 FR 6697, Feb. 10, 2000). In addition to finalizing a single set of emission standards that will apply to all passenger cars, light trucks, and larger passenger vehicles (

e.g.

, large SUVs), the rule requires the introduction of low-sulfur gasoline nationwide. To provide consistency with the fuels that will be in the marketplace, the rule amended the test fuel specifications, effective starting in 2004 when the new standards will take effect. The principal change that was made was a reduction in the allowable levels of sulfur in the test fuel, from a maximum of 0.10 percent by weight to a range of 0.0015 to 0.008 percent by weight.

Given that low-sulfur fuel will be the existing fuel in the marketplace when our program will take effect (and therefore required for service accumulation), we are amending the motorcycle test fuel to reflect the true nature of the fuels that will be available in the marketplace. Doing so will remove the possibility that a test could be conducted with an unrealistically high level of sulfur in the fuel. It will also ensure that motorcycles are tested using the same fuels found in the marketplace.

E. Hardship Provisions

We proposed two types of hardship provisions, one of which was intended specifically for small businesses and the other intended for all manufacturers. The first type of hardship provision allows a small volume motorcycle manufacturer to petition for up to three years additional lead time if the manufacturer can demonstrate that it has taken all possible steps to comply with the standards but the burden of compliance would have a significant impact on the company's solvency. The second type of hardship provision allows a company to apply for hardship relief if circumstances outside of the company's control cause a failure to comply, and the failure to sell the noncompliant product would have a major impact on the company's solvency.

In general, we do not expect that manufacturers will need to use these hardship provisions. However, having such provisions available gives us the flexibility to administratively deal with unexpected situations that may arise as companies work toward compliance with the regulations. Thus, we are adopting these hardship provisions as proposed.

F. Special Compliance Provisions for Small Manufacturers

While the highway motorcycle market is dominated by large companies, there are a large number of small businesses manufacturing motorcycles and motorcycle engines. They are active in both the federal and California markets. California has been much more active than EPA in setting new requirements for highway motorcycles, and indeed, the California requirements have driven the technology demands and timing for highway motorcycle emission controls. We have developed our special compliance provisions partly in response to the technology, timing, and scope of the requirements that apply to the small businesses in California's program. The provisions discussed below will reduce the economic burden on small businesses, allowing harmonization with California requirements in a phased, but timely manner.

The flexibilities described below will be available for small entities with U.S. highway motorcycle annual sales of fewer than 3,000 units per model year (combined Class I, II, and III motorcycles)

and

fewer than 500 employees worldwide. These provisions are appropriate because significant research and development resources may be necessary to meet the emission standards and related requirements. These provisions will reduce the burden while ensuring the vast majority of the program is implemented to ensure timely emission reductions. Many small highway motorcycle manufacturers market unique “classic” and “custom” motorcycles, often with a “retro” appearance, that tends to make the addition of new technologies a uniquely resource-intensive prospect.

1. Delay of Standards for Small Volume Manufacturers

We are delaying compliance with the Tier 1 standard of 1.4 g/km HC+NO

until the 2008 model year for small manufacturers, and at this time, we are not requiring these manufacturers to meet the Tier 2 standard. The existing California regulations do not require small manufacturers to comply with the Tier 2 standard of 0.8 g/km HC+NO

. The California Air Resources Board found that the Tier 2 standard represents a significant technological challenge and is a potentially infeasible limit for these small manufacturers. As noted above, many of these manufacturers market specialty products with a “retro” simplicity and style that may not easily lend itself to the addition of advanced technologies like catalysts and electronic fuel injection. However, the California ARB has acknowledged that, in the course of their progress review planned for 2006, they will revisit their small-manufacturer provisions. We plan to participate with the ARB and others in the 2006 progress review. Following our review of these provisions, as appropriate, we may decide to propose to make changes to the emission standards and related requirements through notice and comment rulemaking, including the applicability of Tier 2 to small businesses.

2. Broader Engine Families

Small businesses have met EPA certification requirements since 1978. Nonetheless, certifying motorcycles to revised emission standards has cost and lead time implications. Relaxing the criteria for what constitutes an engine or vehicle family could potentially allow small businesses to put all of their models into one vehicle or engine family (or more) for certification purposes. Manufacturers would then certify their engines using the “worst case” configuration within the family. This is currently allowed under the existing regulations for small-volume highway motorcycle manufacturers. These provisions remain in place without revision.

3. Averaging, Banking, and Trading

An emission-credit program allows a manufacturer to produce and sell engines and vehicles that exceed the applicable emission standards, as long as the excess emissions are offset by the production of engines and vehicles emitting at levels below the standards. The sales-weighted average of a

manufacturer's total production for a given model year must meet the standards. An emission-credit program typically also allows a manufacturer to bank credits for use in future model years. The emission-credit program we are implementing for all highway motorcycle manufacturers is described above. Some credit programs allow manufacturers to buy and sell credits (trade) between and among themselves. We are not implementing such a provision at this time, but such flexibility could be made available to manufacturers as part of the upcoming technology review.

4. Reduced Certification Data Submittal and Testing Requirements

Current regulations allow significant flexibility for certification by manufacturers projecting sales below 10,000 units of combined Class I, II, and III motorcycles. For example, a qualifying manufacturer must submit an application for certification with a statement that their vehicles have been tested and, on the basis of the tests, conform to the applicable emission standards. The manufacturer retains adequate emission test data, for example, but need not submit it. Qualifying manufacturers also need not complete the detailed durability testing required in the regulations. We are incorporating no changes to these existing provisions.

G. Exemption for Motorcycle Kits and Custom Motorcycles

During the rulemaking we sought comment on the need for emission control requirements for motorcycle engines distinct and separate from the current and future requirements for complete motorcycles. We sought comment in this area because we had identified a small sector in the motorcycle market where the engine manufacturer and chassis manufacturer are not the same entity. This includes two very small parts of the market: one in which motorcycles are assembled by individuals from parts and subassemblies procured from motorcycle kit marketers or other separate sources; and another in which elaborate custom motorcycles are created for display by collectors. At this time, we are not including any certification requirements for engine manufacturers.

See

discussion in Chapter 1.5 of the Summary and Analysis of Comments. The small volume motorcycle manufacturers who purchase the vast majority of engines from other entities for incorporation into the motorcycles will continue to be subject to the regulations, and will continue to meet the requirements of the regulations, as they have in the past.

However, for those individuals who put together a single motorcycle for individual use and businesses that produce a handful of custom motorcycles for display, we believe it is appropriate not to require these entities to have to certify their assembled vehicles. Therefore, we are promulgating provisions for two special exemptions. The first is a one-time exemption for any person building a motorcycle from a kit for individual use. We believe that the small benefit of having single individuals certify to the standards is outweighed by the substantial burden to these individuals in certifying. Moreover, because the engines in such kits generally are built by the same companies as those engines going to the small volume motorcycle manufacturers, who still must certify and who will represent the majority of the engine-makers' production, we believe that most of the engines will be the same or very similar to the engines used in the certified motorcycles. Individuals may not use this provision as a regulatory loophole to modify or customize a certified motorcycle in a manner which adversely affects emissions. This provision is limited to one motorcycle per individual over the life of the provision.

In the case where the owner of the kit motorcycle is not the assembler of the motorcycle, the limitation of one motorcycle per person applies to the purchaser of the kit components of the motorcycle, who we expect is the end user of the motorcycle, rather than to the person or persons who actually assemble the motorcycle. A kit purchaser may have the kit assembled by another party and retain the one-time exemption for the motorcycle. In order to qualify for the exemption under these circumstances, the kit must be purchased by the ultimate owner before assembly begins. Parties or businesses who purchase kit motorcycles for assembly and retail sale are not covered by this exemption.

The second exemption is a sales-limited exemption for elaborate custom motorcycles that are created for display by collectors. The chassis of these “display” motorcycles are usually unique designs, while the engines are either purchased from independent engine manufacturers or custom built from engine components. Current regulations in 40 CFR 85.1707 contain provisions which provide an exemption applicable for all motor vehicles and engines produced solely for display purposes. While these regulations are generally appropriate for display engines, certain aspects of the current custom-built motorcycle market make it appropriate to add a new provision applicable only to such motorcycles. In particular, because these motorcycles are often sold to collectors, the current exemption, which does not apply to engines that are sold, would not be applicable. Therefore, we are adding a limited exemption for custom manufacturers to sell a small number of these engines every year, with the conditions discussed below. It is our understanding that these motorcycles are rarely operated on public streets. Therefore, as a condition of this exemption, these motorcycles would be allowed to operate on public streets or highways only as necessary to the display purpose, such as traveling to and from motorcycle shows. No request for the exemption is necessary for motorcycles that will not be sold or leased. However, manufacturers planning to sell motorcycles for display under this exemption will be required to notify EPA of their intent before they sell any exempted motorcycles. They must also maintain sales records of exempted motorcycles for at least three years and make them available to EPA upon request. Sales under this exemption would be limited to less than 25 per year per manufacturer. Every motorcycle exempted under this provision must include a label that identifies the manufacturer and includes the following statement: THIS MOTORCYCLE IS EXEMPT FROM EPA EMISSION REQUIREMENTS. ITS USE ON PUBLIC ROADS IS LIMITED PURSUANT TO 40 CFR 86.407-78(c). We will generally allow manufacturers to locate the label where it will not detract from the appearance of the motorcycle. For example, We could allow the label to be located under the seat.

As noted elsewhere, EPA may be revisiting several issues related to motorcycle standards in the context of the 2006 technology review and review of a possible World Motorcycle Test Cycle. One of the issues we may be reviewing at that time is whether it is appropriate to regulate motorcycle engine manufacturers or motorcycle kit manufacturers under the motorcycle regulations. If we agree to regulate loose engine sales at that time, these exemption provisions may no longer be necessary, since both kit builders and custom manufacturers would be able to purchase certified engines. Therefore, we may propose to remove or modify these provisions in the future.

V. Technological Feasibility of the Exhaust Emission Standards

A. Class I Motorcycles and Motorcycle Engines Under 50cc

As we have described earlier we are applying the current California standard for Class I motorcycles to motorcycles with displacements of less than 50cc (

e.g.

, many motor scooters). These motorcycles are currently not subject to regulation by the U.S. EPA or the State of California. They are, however, subject to emission standards in Europe and much of the rest of the world. Historically these motorcycles have been powered by 2-stroke engines, but a trend appears to be developing that would result in many of these being replaced by 4-stroke engines or possibly by advanced technology 2-stroke engines, in some cases with catalysts. This trend is largely due to emission requirements in the nations where these types of two-wheelers are popular forms of transportation.

It has already been demonstrated that the 4-stroke engine is capable of meeting the standards. Class I motorcycles above 50cc are already meeting these standards, most of them employing a 4-stroke engine with minimal additional emission controls. For example, all 2002 model year Class I motorcycles (10 engine families) were certified at levels ranging from 0.4 to 0.9 grams per kilometer HC. The 2003 Class I motorcycle models (11 engine families) were certified at similar levels with the exception of two newly introduced models, each of which is certified at a level above 3.0 g/km HC. All of these achieve the standards with 4-stroke engine designs, and only three incorporate additional technology (secondary air injection or a catalyst). These current engines range from 80 to 151cc in displacement, which provides an indication that small 4-stroke scooter engines are capable of meeting the standards. In a test program conducted by the Japan Automobile Research Institute, a 49cc 4-stroke achieved average HC emissions of 0.71 g/km, a level that falls well under the 1.0 g/km standard we are adopting.

The technological feasibility of meeting a 1.0 g/km HC standard was also supported by MIC if EPA made appropriate revisions to the test cycle and the useful life. We evaluated these recommendations and have adopted both of them in this final rule. The Association of European Motorcycle Manufacturers (ACEM) confirmed that European manufactures will seek to export to the U.S. the same motorcycles under 50cc that they develop for the European market, and that standards in the E.U. are forcing the transition to 2-stroke direct injection and 4-stroke EFI technologies in 2002 and 2003.

ACEM also confirmed the feasibility of meeting the new U.S. standard and aligned with MIC comments regarding the test cycle and useful life.

“WMTC 2nd step validation test results in Japan,” Japan Automobile Research Institute, Nov. 29, 2001. Available for review in Docket A-2000-02.

ACEM members are: Aprilia, Benelli, BMW, Derbi, Ducati, Honda, Kawasaki, KTM, Malaguti, MV Augusta, Peugeot, Piaggio, Suzuki, Triumph, Yamaha.

In order to meet more stringent standards being implemented worldwide, manufacturers are developing and implementing a variety of technology approaches. Honda, perhaps the largest seller of scooters in the U.S., has entirely eliminated 2-stroke engines from its scooter product lines as of the 2002 model year. They continue to offer a 50cc model, but with a 4-stroke engine. Both of Aprilia's 49cc scooters available in the U.S. have incorporated electronic direct injection technology, which, in the case of one model, enables it to meet the “Euro-2” standards of 1.2 grams per kilometer HC and 0.3 grams per kilometer NO

, without use of a catalytic converter.

Piaggio, while currently selling a 49cc basic 2-stroke scooter in the U.S., expects to begin production of a direct injection version in 2002, and a 4-stroke 50cc scooter is also in development. Numerous 49cc models marketed by Piaggio in Europe are available either as a 4-stroke or a 2-stroke with a catalyst. Piaggio, also an engine manufacturer and seller, is already offering 50cc 4-stroke and 50cc direct injection 2-stroke engines that meet the Euro-2 limits to its customers for incorporation into scooters.

Aprila Web site,

http://www.apriliausa.com/ridezone/ing/models/scarabeo50dt/moto.htm

and

http://www.aprilia.com/portale/eng/cafera articolo.phtm1?id=14

. Available for review in public docket A-2000-02.

The U.S. represents a very small portion of the market for small motorcycles and scooters. There are few, if any, manufacturers that develop a small-displacement motorcycle exclusively for the U.S. market; the domestic sales volumes do not appear large enough at this time to support an investment of this kind. The Italian company Piaggio (maker of the Vespa scooters), for example, sold about as many scooters worldwide in 2000 (about 480,000) as the entire volume of highway motorcycles of all sizes sold in the U.S. in that year. U.S. sales of Vespas in 2000 amounted to about 4800. The largest scooter markets today are in South Asia and Europe, where millions are sold annually. In Taiwan alone almost 800,000 motorcycles were sold domestically. More than one third of these were powered by 2-stroke engines. Two- and three-wheelers constitute a large portion of the transportation sector in Asia, and in some urban areas these vehicles—many of them powered by 2-stroke engines—can approach 75 percent of the vehicle population. According to a World Bank report, two-stroke gasoline engine vehicles are estimated to account for about 60 percent of the total vehicle fleet in South Asia.

Improving Urban Air Quality in South Asia by Reducing Emissions from Two-Stroke Engine Vehicles. Masami Kojima, Carter Brandon, and Jitendra Shah. December 2000. Prepared for the World Bank. Available in the public docket for a review (Docket A-2000-01; document II-D-191), or on the Internet at:

http://www.worldbank.org/html/fpd.esmap/publication/airquality.html.

Many nations are now realizing that the popularity of these vehicles and the high density of these vehicles in urban areas are contributing to severe air quality problems. As a consequence, some of the larger markets for small motorcycles in Asia and India are now placing these vehicles under fairly strict regulation. It is clear that actions in these nations will move the emission control technology on small motorcycles, including those under 50cc, in a positive direction. For example, according to the World Bank report, as of 2000 catalytic converters are installed in all new two-stroke engine motorcycles in India, and 2003 standards in Taiwan will effectively ban new two-strokes with emission standards so stringent that only a four-stroke engine is capable of meeting them.

Given the emerging international picture regarding emission standards for scooters, we believe that scooter manufacturers will be producing scooters of less than 50cc displacement that meet our standards well in advance of the 2006 model year, the first year we will subject this category of motorcycle to U.S. emission standards. We expect that small entities that import scooters into the U.S. from the larger scooter markets will be able to import complying vehicles. We requested comment on this assessment in the NPRM and received none indicating otherwise.

There are numerous other factors in the international arena that may affect the product offerings in the less than 50cc market segment. For example, the European Union recently changed the requirements regarding insurance and

helmet use for under 50cc scooters and mopeds. Previously, the insurance discounts and lack of helmet requirements in Europe provided two relatively strong incentives to purchasers to consider a 49cc scooter. Recently, however, the provisions were changed such that helmets are now required and the insurance costs are comparable to larger motorcycles. The result was a drop of about 30 percent in European sales of 49cc scooters in 2001 due to customers perceiving little benefit from a 49cc scooter relative to a larger displacement engine.

B. Class I and Class II Motorcycles Between 50 and 180cc

As discussed above, we are adopting a new exhaust emission standards of 1.0 g/km HC for Class I and Class II motorcycles. The existing CO standard is unchanged. These standards have been in place in California since 1982. The question of whether or not these standards are technically feasible has been answered in the affirmative, since 21 of the 22 EPA-certified 2001 model year motorcycle engine families in these classes are already certified to these standards, all 24 of the 2002 model year engine families meet these standards, and 22 of 29 2003 model year engine families meet these standards. These 29 model year 2003 engine families are all powered by four-stroke engines, with a variety of emission controls applied, including basic engine modifications on almost all engine families, secondary air injection on three engine families, and catalysts on four engine families.

C. Class III Motorcycles

1. Tier 1 Standards

In the short term, the Tier 1 standard of 1.4 g/km HC+NO

reflects the goal of achieving emission reductions that can be met with reasonably available control technologies, primarily involving engine modifications rather than catalytic converters. As noted earlier, this standard will be effective starting with the 2006 model year. Based on current certification data, a number of existing engine families already could comply with this standard or will need relatively simple modifications to comply. In other cases, the manufacturers will need to use control technologies that are available but are not yet used on their particular cycles (

e.g.

, electronic fuel injection to replace carburetors, changes to cam lobes/timing, etc.). For the most part, manufacturers will not need to use advanced technologies such as close-coupled, closed-loop three-way catalysts.

While manufacturers will use various means to meet the Tier 1 standard, there are four basic types of existing, non-catalyst-based, emission-control systems available to manufacturers. The most important of these is the use of secondary pulse-air injection. Other engine modifications and systems include more precise fuel control, better fuel atomization and delivery, and reduced engine-out emission levels from engine changes. The combinations of low-emission technologies ultimately chosen by motorcycle manufacturers are dependent on the engine-out emission levels of the vehicle, the effectiveness of the prior emission-control system, and individual manufacturer preferences.

Secondary pulse-air injection, as demonstrated on current motorcycles, is applied using a passive system (

i.e.

, no air pump involved) that takes advantage of the flow of gases (“pulse”) in the exhaust pipes to draw in fresh air that further combusts unburned hydrocarbons in the exhaust. The extra air causes further combustion to occur, thereby controlling more of the hydrocarbons that escape the combustion chamber. This type of system is relatively inexpensive and uncomplicated because it does not require an air pump; air is drawn into the exhaust through a one-way reed valve due to the pulses of negative pressure inside the exhaust pipe. Secondary pulse-air injection is one of the most effective non-catalytic emission-control technologies; compared to engines without the system, reductions of 10 to 40 percent for HC are possible with pulse-air injection. Eighty—or about half—of the 162 2003 model year Class III engine families certified for sale in the U.S. employ secondary pulse-air injection to help meet the current California standards. We anticipate that most of the remaining engine families will use this technique to help meet the Tier 1 and Tier 2 standards. There are 47 2003 engine families that are certified using only engine management techniques (

e.g.

, no use of catalysts, fuel injection, secondary air injection, or oxygen sensors). The average certification HC level of these families is 1.17 g/km. By comparing this to the certification results of engine families that employ secondary air injection as the only means of emission control beyond engine modifications, we can gain some measure of the effectiveness of secondary air injection. We find that the currently certified 2003 models which employ secondary air injection have an average certification level of 0.91 g/km, a reduction of 0.26 g/km (or 22%) relative to those using only engine modification techniques.

Improving fuel delivery and atomization primarily involves the replacement of carburetors, currently used on most motorcycles, with more precise fuel injection systems. There are several types of fuel injection systems and components manufacturers can choose, including throttle-body injection systems, multi-point injection systems, and sequential multi-point fuel injection systems. Unlike conventional multi-point fuel injection systems that deliver fuel continuously or to paired injectors at the same time, sequential fuel injection can deliver fuel precisely when needed by each cylinder. The most likely type of fuel injection manufacturers will choose to help meet the Tier 1 standard is sequential multi-point fuel injection (SFI).

Motorcycle manufacturers are already using sequential fuel injection (SFI). Of the 162 2003 model year Class III motorcycle engine families certified to emission standards, at least 29 employ SFI systems.

We anticipate increased application of this or similar fuel injection systems to achieve the more precise fuel delivery needed to help meet the Tier 1 and Tier 2 standards. We analyzed the EPA certification data in the same way as done above with secondary air injection to estimate the effect of using SFI vehicle on emissions. Again, we identified the baseline of 47 engine families using the limited technologies and with an average certification level of 1.17 g/km HC, and compared the emissions of these engines with the emissions of engines using SFI. What we find is that use of all types of fuel injection can significantly reduce emissions. If we analyze those engine families that use some form of fuel injection other than SFI we see an average HC certification level of 1.09 g/km, a modest reduction of about 7 percent. However, the engines using SFI had significantly lower HC emissions on average of 0.72

g/km, a reduction of almost 40 percent. While this provides some indication of what can be achieved with fuel injection techniques (including SFI), it does not necessarily demonstrate the full potential of this technology. At this point in time it appears that SFI can get motorcycle certification levels down to about 0.4-0.6 g/km HC (certification at levels in this range can be seen in several current motorcycles that employ no other emission controls), but in the context of more stringent standards the manufacturers are likely to be able to accomplish even more with SFI, and further reductions by teaming SFI with additional emission reduction techniques.

When manufacturers certify to EPA emission standards, they report the fuel delivery system used by each certified model as carbureted or fuel injected. They also report the emission control technologies used on each model to meet the emission standards. When reporting the fuel delivery system, they only indicate whether the system is carbureted or fuel injected, but not the specific type of fuel injection that is installed. When reporting the control technologies 29 models indicated the use of sequential fuel injection. However, there may be some inconsistencies in how these technologies are reported, and we believe that there may be models that employ sequential fuel injection that are shown in our database as being fuel injected, but the manufacturer may not have also specifically listed sequential fuel injection as a control technology on the motorcycle model. This is why we say “at least” 29 models are currently using sequential fuel injection.

In addition to the techniques mentioned above, various engine modifications can be made to improve emission levels. Engine modifications include a variety of techniques designed to improve fuel delivery or atomization; promote “swirl” (horizontal currents) and “tumble” (vertical currents); maintain tight control on air-to-fuel (A/F) ratios; stabilize combustion (especially in lean A/F mixtures); optimize valve timing; and retard ignition timing. Emission performance can be improved, for example, by reducing crevice volumes in the combustion chamber. Unburned fuel can be trapped momentarily in crevice volumes before being subsequently released. Since trapped and re-released fuel can increase engine-out emissions, the elimination of crevice volumes would be beneficial to emission performance. To reduce crevice volumes, manufacturers can evaluate the feasibility of designing engines with pistons that have reduced, top “land heights” (the distance between the top of the piston and the first ring).

Lubrication oil which leaks into the combustion chamber also has a detrimental effect on emission performance since the heavier hydrocarbons in oil do not oxidize as readily as those in gasoline and some components in lubricating oil may tend to foul a catalyst and reduce its effectiveness. Also, oil in the combustion chamber may trap HC and later release the HC unburned. To reduce oil consumption, manufacturers can tighten the tolerances and improve the surface finish on cylinders and pistons, piston ring design and materials, and exhaust valve stem seals to prevent excessive leakage of lubricating oil into the combustion chamber.

Increasing valve overlap is another engine modification that can help reduce emissions. This technique helps reduce NO

generation in the combustion chamber by essentially providing passive exhaust gas recirculation (EGR). When the engine is undergoing its pumping cycle, small amounts of combusted gases flow past the intake valve at the start of the intake cycle. This creates what is essentially a passive EGR flow, which is then either drawn back into the cylinder or into another cylinder through the intake manifold during the intake stroke. These combusted gases, when combined with the fresh air/fuel mixture in the cylinder, help reduce peak combustion temperatures and NO

levels. This technique can be implemented by making changes to cam timing and intake manifold design to optimize NO

reduction while minimizing impacts to HC emissions.

Secondary pulse-air injection and engine modifications already play an important part in reducing emission levels, and we expect increased uses of these techniques to help meet the Tier 1 standard. Direct evidence of the extent to which these technologies can help manufacturers meet the Tier 1 standard can be found in EPA's highway motorcycle certification database. This database is comprised of publicly-available certification emission levels as well as some confidential data reported by the manufacturers pursuant to existing motorcycle emission certification requirements.

We do not expect any of these possible changes to adversely affect performance. Indeed, the transition to some of these technologies (

e.g.

, advanced fuel injection) is expected to improve performance, fuel economy, and reliability.

2. Tier 2 Standards

In the long term, the Tier 2 HC+NO

standard of 0.8 g/km will ensure that manufacturers will continue to develop and improve emission control technologies. The Tier 2 standard will become effective in the 2010 model year. We believe this standard is technologically feasible, though it will present some technical challenges for manufacturers. Several manufacturers are, however, already using some of the technologies that will be needed to meet this standard. In addition, our implementation time frame gives manufacturers two years of experience in meeting this standard in California before having to meet it on a nationwide basis. Several manufacturers already use closed-loop, three-way catalysts on a number of their product lines. At least one manufacturer has already certified several models to the Tier 2 standards levels, and at least one of these models is being sold nationwide. A number of additional models currently in the market may also meet the Tier 2 standards, depending on NO

levels, using combinations of catalysts, fuel injection, secondary air injection, and other engine modifications. The current average HC certification level for Class III motorcycles is 0.93 g/km, with about forty engine families from a variety of manufacturers at levels of 0.5 g/km or lower. We expect that the provided six to seven years of lead time prior to meeting these standards on a nationwide basis will allow manufacturers to optimize these and other technologies to meet the Tier 2 standard.

To meet the Tier 2 standard for HC+NO

, manufacturers will likely use more advanced engine modifications and secondary air injection. Specifically, we believe manufacturers will use computer-controlled secondary pulse-air injection (

i.e.

, the injection valve would be connected to a computer-controlled solenoid). In addition to these systems, manufacturers will probably need to use catalytic converters on some motorcycles to meet the Tier 2 standards. There are two types of catalytic converters currently in use: two-way catalysts (which control only HC and CO) and three-way catalysts (which control HC, CO, and NO

). Under the Tier 2 standard, manufacturers will need to minimize levels of both HC and NO

. Therefore, to the extent catalysts are used, manufacturers will likely use a three-way catalyst in addition to engine modifications and computer-controlled secondary pulse-air injection.

As discussed previously, improving fuel control and delivery provides emission benefits by helping to reduce engine-out emissions and minimizing the exhaust variability which the catalytic converter experiences. One method for improving fuel control is to provide enhanced feedback to the computer-controlled fuel injection system through the use of heated oxygen sensors. Heated oxygen sensors (HO2S) are located in the exhaust manifold to monitor the amount of oxygen in the exhaust stream and provide feedback to the electronic control module (ECM). These sensors allow the fuel control system to maintain a tighter band around the stoichiometric A/F ratio than conventional oxygen sensors (O2S). In this way, HO2S assist vehicles in achieving precise control of the A/F ratio and thereby enhance the overall emissions performance of the engine. At least one manufacturer is currently using this technology on several 2003 as

well as previous model year engine families.

In order to further improve fuel control, some motorcycles with electronic controls may utilize software algorithms to perform individual cylinder fuel control. While dual oxygen sensor systems are capable of maintaining A/F ratios within a narrow range, some manufacturers may desire even more precise control to meet their performance needs. On typical applications, fuel control is modified whenever the O2S determines that the combined A/F of all cylinders in the engine or engine bank is “too far” from stoichiometric. The needed fuel modifications (

i.e.

, inject more or less fuel) are then applied to all cylinders simultaneously. Although this fuel control method will maintain the “bulk” A/F for the entire engine or engine bank around stoichiometric, it would not be capable of correcting for individual cylinder A/F deviations that can result from differences in manufacturing tolerances, wear of injectors, or other factors.

With individual cylinder fuel control, A/F variation among cylinders will be diminished, thereby further improving the effectiveness of the emission controls. By modeling the behavior of the exhaust gases in the exhaust manifold and using software algorithms to predict individual cylinder A/F, a feedback fuel control system for individual cylinders can be developed. Except for the replacement of the conventional front O2S with an HO2S sensor and a more powerful engine control computer, no additional hardware is needed in order to achieve individual cylinder fuel control. Software changes and the use of mathematical models of exhaust gas mixing behavior are required to perform this operation.

In order to maintain good driveability, responsive performance, and optimum emission control, fluctuations of the A/F must remain small under all driving conditions including transient operation. Virtually all current fuel systems in automobiles incorporate an adaptive fuel control system that automatically adjusts the system for component wear, varying environmental conditions, varying fuel composition, etc., to more closely maintain proper fuel control under various operating conditions. For some current fuel control systems, this adaptation process affects only steady-state operating conditions (

i.e.

, constant or slowly changing throttle conditions). However, most vehicles are now being introduced with adaptation during “transient” conditions (

e.g.

, rapidly changing throttle positions).

Accurate fuel control during transient driving conditions has traditionally been difficult because of the inaccuracies in predicting the air and fuel flow under rapidly changing throttle conditions. Because of air and fuel dynamics (fuel evaporation in the intake manifold and air flow behavior) and the time delay between the air flow measurement and the injection of the calculated fuel mass, temporarily lean A/F ratios can occur during transient driving conditions that can cause engine hesitation, poor driveability and primarily an increase in NO

emissions. However, by utilizing fuel and air mass modeling, vehicles with adaptive transient fuel control are more capable of maintaining accurate, precise fuel control under all operating conditions. Virtually all cycles will incorporate adaptive transient fuel control software; motorcycles with computer controlled fuel injection can also benefit from this technique at a relatively low cost.

Three-way catalytic converters traditionally utilize rhodium and platinum as the catalytic material to control the emissions of all three major pollutants (hydrocarbons (HC), CO, NO

). Although this type of catalyst is very effective at converting exhaust pollutants, rhodium, which is primarily used to convert NO

, tends to thermally deteriorate at temperatures significantly lower than platinum. Recent advances in palladium and tri-metal (

i.e.

, palladium-platinum-rhodium) catalyst technology, however, have improved both the light-off performance (light-off is defined as the catalyst bed temperature where pollutant conversion reaches 50-percent efficiency) and high temperature durability over previous catalysts. In addition, other refinements to catalyst technology, such as higher cell density substrates and adding a second layer of catalyst washcoat to the substrate (dual-layered washcoats), have further improved catalyst performance from just a few years ago.

Typical cell densities for conventional catalysts used in motorcycles are less than 300 cells per square inch (cpsi). To meet the Tier 2 standard, we expect manufacturers to use catalysts with cell densities of 300 to 400 cpsi. If catalyst volume is maintained at the same level (we assume volumes of up to 60 percent of engine displacement), using a higher density catalyst effectively increases the amount of surface area available for reacting with pollutants. Catalyst manufacturers have been able to increase cell density by using thinner walls between each cell without increasing thermal mass (and detrimentally affecting catalyst light-off) or sacrificing durability and performance.

In addition to increasing catalyst volume and cell density, we believe that increased catalyst loading and improved catalyst washcoats will help manufacturers meet the Tier 2 standards. In general, increased precious metal loading (to a point) will reduce exhaust emissions because it increases the opportunities for pollutants to be converted to harmless constituents. The extent to which precious metal loading is increased will be dependent on the precious metals used and other catalyst design parameters. We believe recent developments in palladium/rhodium catalysts are very promising since rhodium is very efficient at converting NO

, and catalyst suppliers have been investigating methods to increase the amount of rhodium in catalysts for improved NO

conversion.

Double layer technologies allow optimization of each individual precious metal used in the washcoat. This technology can provide reduction of undesired metal-metal or metal-base oxide interactions while allowing desirable interactions. Industry studies have shown that durability and pollutant conversion efficiencies are enhanced with double layer washcoats. These recent improvements in catalysts can help manufacturers meet the Tier 2 standard at reduced cost relative to older three-way catalysts.

New washcoat formulations are now thermally stable up to 1050 °C. This is a significant improvement from conventional washcoats, which are stable only up to about 900 oC. With the improvements in light-off capability, catalysts may not need to be placed as close to the engine as previously thought. However, if placement closer to the engine is required for better emission performance, improved catalysts based on the enhancements described above would be more capable of surviving the higher temperature environment without deteriorating. The improved resistance to thermal degradation will allow closer placement to the engines where feasible, thereby providing more heat to the catalyst and allowing them to become effective quickly.

It is well established that a warmed-up catalyst is very effective at converting exhaust pollutants. Recent tests on advanced catalyst systems in automobiles have shown that over 90 percent of emissions during the Federal Test Procedure (FTP) are now emitted during the first two minutes of testing after engine start up. Similarly, the

highest emissions from a motorcycle occur shortly after start up. Although improvements in catalyst technology have helped reduce catalyst light-off times, there are several methods to provide additional heat to the catalyst. Retarding the ignition spark timing and computer-controlled, secondary air injection have been shown to increase the heat provided to the catalyst, thereby improving its cold-start effectiveness.

In addition to using computer-controlled secondary air injection and retarded spark timing to increase the heat provided to the catalyst, some vehicles may employ warm-up, pre-catalysts to reduce the size of their main catalytic converters. Palladium-only warm-up catalysts (also known as “pipe catalysts” or “Hot Tubes”) using ceramic or metallic substrates may be added to further decrease warm-up times and improve emission performance. Although metallic substrates are usually more expensive than ceramic substrates, some manufacturers and suppliers believe metallic substrates may require less precious metal loading than ceramic substrates due to the reduced light-off times they provide.

Improving insulation of the exhaust system is another method of furnishing heat to the catalyst. Similar to close-coupled catalysts, the principle behind insulating the exhaust system is to conserve the heat generated in the engine for aiding catalyst warm-up. Through the use of laminated thin-wall exhaust pipes, less heat will be lost in the exhaust system, enabling quicker catalyst light-off. As an added benefit, the use of insulated exhaust pipes will also reduce exhaust noise. Increasing numbers of manufacturers are expected to utilize air-gap exhaust manifolds (

i.e.

, manifolds with metal inner and outer walls and an insulating layer of air sandwiched between them) for further heat conservation.

Besides the hardware modifications described above, motorcycle manufacturers may borrow from other current automobile techniques. These include using engine calibration changes such as a brief period of substantial ignition retard, increased cold idling speed, and leaner air-fuel mixtures to quickly provide heat to a catalyst after cold-starts. Only software modifications are required for an engine which already uses a computer to control the fuel delivery and other engine systems. For these engines, calibration modifications provide manufacturers with an inexpensive method to quickly achieve light-off of catalytic converters. When combined with pre-catalysts, computer-controlled secondary air injection, and the other heat conservation techniques described above, engine calibration techniques may be very effective at providing the required heat to the catalyst for achieving the Tier 2 standard.

D. Safety and Performance Impacts

We noted in the NPRM that the nature of motorcycling makes riders particularly aware of any safety issues that confront them. Many motorcycle riders and their organizations submitted comments on the NPRM regarding their concerns that the proposed standards would adversely affect both performance and safety. These issues are discussed in detail in the Summary and Analysis of Comments; the remainder of this section summarizes our key findings regarding these issues.

Motorcycle riders are inherently closer to the engine and exhaust pipes than the driver of an enclosed vehicle, and the engine components tend to be more exposed and accessible as well. Because of this fact, we received many comments regarding the potential safety risk of catalytic converters, and many questioned whether this emission control device could be implemented on motorcycles without increasing the risk of injury to the rider and/or passenger. An economic impact study submitted by the Motorcycle Riders Foundation claimed that “EPA ignores the issue of rider safety,” apparently basing this claim on a word search of the rulemaking documents for the terms “rider safety” and “consumer safety.” In fact, the NPRM contained several paragraphs regarding the issue of safety as it relates to the use of catalytic converters on motorcycles.

Because of the serious nature of the concerns expressed by riders we expanded our assessment of the potential risks of using catalytic converters as an emission control device on motorcycles. Our complete analysis, described in the Summary and Analysis of Comments, involved the following:

• An improved assessment of the current use of catalytic converters on motorcycles, both in the U.S. and worldwide;

• Feedback from the motorcycle manufacturers regarding this issue;

• An analysis of exhaust- and catalyst-based complaints filed by consumers with the National Highway Traffic Safety Administration's Office of Defects Investigation, including feedback from manufacturers on the nature of these complaints; and

• An assessment of the technological approaches to isolating the rider and/or passenger from the heat of a catalytic converter.

We found that in the last five years at least 16 manufacturers have certified dozens of models equipped with catalytic converters. In the last two years sales of catalyst-equipped models in each year have approached twenty percent of all motorcycles sold in the U.S., and we conservatively estimate that there are at least 150,000 catalyst-equipped motorcycles of all sizes and styles on the roads in the U.S. today. Given that the total annual mileage accumulated on these motorcycles in the U.S. likely exceeds 300 million miles, the rider experience with the emission control devices is not trivial. Given this experience, we believe that there has been ample opportunity to assess the issue of catalyst safety, not just on a hypothetical basis but on the basis of actual manufacturing and on-road riding experience. Any serious concerns would be likely to be brought to the attention of manufacturers and/or the National Highway Traffic Safety Administration (NHTSA). Our analysis of the NHTSA database on consumer complaints revealed a small number related to the exhaust pipe, and only seven related to heat from the exhaust pipe. (In 1998 there were an estimated 5.4 million on-highway motorcycles in use in the United States.) These seven complaints are detailed in Table V.D-1.

Table V.D-1.—National Highway Traffic Safety Administration, Office of Defects Investigation; Database of Consumer Complaints: Complaints Regarding Excess Heat from Exhaust Pipes

No.

Complaint

Passenger on motorcycle received burns on leg from hot mufflers.

Muffler not designed with heat shield, causing burn injury to driver when motorcycle turned over.

Exhaust manifold reaches temperatures so high that it has an orange glow. Manufacturer knows of problem, and there isn't a solution. Consumer will add additional information.

Consumer states that when at a stop the exhaust pipe will glow red and this can cause injuries to the consumer. Dealer notified.

Exhaust system cross over pipe is located too close to seat, causing driver to be burned while driving, even if properly dressed.

Consumer states exhaust pipes are positioned below foot pegs so that when you come to a stop and put feet down, it's very likely that pant leg will at least brush up against pipe. Consumer has ruined clothes because of this. Manufacturer does not feel this is a problem, they suggested to consumer that he buy after market exhaust guards, which are expensive.

Exhaust pipes are positioned below foot pegs so that when you come to a stop and put your foot down you will brush up against hot pipe.

Source:

National Highway Traffic Safety Administration, Office of Defects Investigation. Consumer Complaints Database. See

http://www-odi.nhtsa.dot.gov/cars/problems/complain/.

Two of the seven (Nos. 1 and 2 in the table above) were clearly regarding motorcycles without catalysts, and of the remaining five only two were regarding models that clearly did have catalysts (Nos. 6 and 7). We are unable to determine whether complaints numbered 3-5 involve motorcycles with catalysts; although the manufacturer has been using catalysts for a number of years, sales of these motorcycles have been limited to California to date. The complaints shown in the table originated from Ohio, New York, and Arizona. The manufacturers of the motorcycles reflected in these five complaints unanimously stated their belief that these are isolated cases, that they have no record of consumer complaints indicating that widespread problems exist, and that they make every effort to protect the rider from injury or harm.

We are confident that manufacturers can design and produce motorcycles that respond to these safety concerns, and information submitted by the manufacturers supports our assessment that catalytic converters can be safely integrated into motorcycle designs. There are a number of approaches that manufacturers are using today to protect the rider from excessive heat. Some motorcycle designs permit the catalyst to be placed on the underside of the motorcycle where it is unable to contact the rider. Other manufacturers will use a double-pipe exhaust system to reduce heat loss, allowing the exhaust gases to remain hot before reaching the catalyst while maintaining lower exterior temperatures. Some manufacturers are placing the catalyst inside the muffler or close to the manifold in areas where it is unlikely to be contacted by the rider or passenger. Footrests can be shielded and pipes can be insulated to reduce the exterior transmission of heat. The fact that these approaches are already being successfully employed, combined with the significant lead time provided for the Tier 2 standard, leads us to conclude that catalysts can be safely integrated into both current and future motorcycle designs.

Every motorcycle manufacturer who either testified at the public hearing or provided written comments on the proposed rule has unequivocally stated that they can build motorcycles that will meet the standards with no negative impact on safety or performance relative to motorcycles manufactured today. Finally, MECA addressed this issue at the public hearing by noting that catalyst technology has been applied to over 15 million two- and three-wheelers worldwide. There is no indication from any nation worldwide—some of which are far more dependent on motorcycles as daily transportation than we are in the U.S.—that the use of catalysts on motorcycles presents a significant risk to the rider.

We do not expect any of these possible technology changes to adversely affect performance. Indeed, the transition to some of these technologies (

e.g.

, advanced fuel injection) would be expected to improve performance, fuel economy, and reliability. In the last ten years, and especially within the

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