Standards for Emissions From Natural Gas-Fueled, and Liquefied Petroleum Gas-Fueled Motor Vehicles and Motor Vehicle Engines, and Certification Procedures for Aftermarket Conversions; Final Rule ENVIRONMENTAL PROTECTION AGENCY
Federal RegisterSep 21, 1994
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SUMMARY: Today's rule provides emission standards and test procedures
for the certification of new natural gas-fueled, and liquefied
petroleum gas-fueled light-duty vehicles, light-duty trucks, heavy-duty
engines and vehicles, and motorcycles. The regulations are effective
with the 1997 model year, although optional certification prior to the
1997 model year will be available. Today's rule also provides fuel
economy test procedures and calculation equations for natural gas-
fueled light-duty vehicles and trucks, effective upon publication, to
allow these vehicles to be included in a manufacturer's corporate
average fuel economy (CAFE). Finally, today's rule provides procedures
for the certification of aftermarket conversion equipment to allow a
vehicle or engine to operate completely or in part on a fuel other than
the fuel for which it was originally designed and manufactured.
This action is being taken in order to remove the possibility that
the absence of such standards could hinder the development of natural
gas and liquefied petroleum gas as transportation fuels. These
standards are intended to provide a comparable degree of environmental
protection to that afforded by the standards applicable to gasoline,
diesel and methanol vehicles, and to ensure that aftermarket
conversions do not degrade the emissions performance of the vehicles or
engines being converted.
DATES: Except as specified elsewhere in this DATES section, this final
rule is effective September 21, 1994.
The effective date of Secs. 80.32, 80.33, 86.001-9(d)(1)(iv),
86.001-28(h), 86.004-9(d)(1)(iv), 86.004-28(h), 86.098-8(d)(1)(iv),
86.098-28(h), 86.099-8(d)(1)(iv), 86.150-98(d) and 86.157-98 is
November 21, 1994, unless notice is received by October 21, 1994 that
interested parties wish to submit adverse or critical comments on these
sections. If the effective date is changed, timely notice will be
published in the Federal Register.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of September 21, 1994, except as specified elsewhere in this DATES
section.
40 CFR 85.503, 85.505, 86.542-90, 86.094-23, 86.095-24, 86.095-35,
86.1242-90, 86.098-28, 86.113-94, 86.1344-94, 86.142-90, 86.150-98,
86.513-94 and 600.113-93 are not effective until the Office of
Management and Budget (OMB) has approved the information collection
requirements contained in them. A document will be published in the
Federal Register when OMB has approved the information collection
requirements.
ADDRESSES: Written comments on those sections effective November 21,
1994 should be submitted both to the contact person for this rule (see
For Further Information Contact) and to the docket for this rulemaking
at the following address. Materials relevant to this rule have been
placed in Docket No. A-92-14 by EPA. The docket is located at: Air
Docket Section, U.S. Environmental Protection Agency, 401 M Street,
SW., Washington, DC 20460 in room M-1500, Waterside Mall (ground
floor), and may be inspected between 8 a.m. and 4 p.m. on weekdays. EPA
may charge a reasonable fee for copying docket materials. In addition,
copies of the Summary and Analysis of Comments document, which develops
certain issues relevant to this final rulemaking, may be obtained by
request from the contact person below. This document contains the
Agency's response to the public comments received in regard to the
Notice of Proposed Rulemaking (NPRM).
FOR FURTHER INFORMATION CONTACT: Mr. John Mueller, Regulation
Development and Support Division, U.S. Environmental Protection Agency,
2565 Plymouth Road, Ann Arbor, Michigan 48105: phone (313) 668-4275. To
obtain copies of this final rule or the Summary and Analysis of
Comments document please contact Ms. Donna Hoover at (313) 668-4278 or
at the above address.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Introduction
II. Description of Action
A. Timing
B. New Vehicle Standards
C. Certification Test Fuel Specification
D. Test Procedures
E. Fuel Economy
F. Aftermarket Conversions
G. Fees
III. Public Participation
A. Timing of Requirements
B. Standards for HC
1. NMHC vs. THC Standards
2. Heavy-Duty NMHC Standards
3. Evaporative Emission Standards
C. Refueling Emission Standards
1. Natural Gas
2. LPG Vehicle/Pump Interface
3. LPG Tank Venting
D. Standards for CO and Crankcase Emissions
1. Idle CO
2. Crankcase Emissions
E. On-Board Diagnostics
F. HC Measurement
G. Fuel Composition
H. Fuel Economy
I. Aftermarket Conversions
1. Applicability
2. Test Procedures
3. On-board Diagnostics
4. Liability
IV. Environmental Effects
V. Economic Impacts
VI. Statutory Authority
VII. Executive Order 12866
VIII. Reporting and Recordkeeping Requirements
IX. Impact on Small Entities
X. Judicial Review
I. Introduction
Recently there has been increasing interest in the use of non-
petroleum transportation fuels for a variety of reasons, including the
potential environmental benefits offered by these fuels. Natural gas
and liquefied petroleum gas (LPG) are among the more prominent of these
fuels, along with methanol and ethanol. EPA promulgated emission
standards for methanol-fueled vehicles on April 11, 1989 (54 FR 14426)
due to the imminent commercialization of those vehicles. However, there
are currently no emission standards in place for vehicles which
operate, all or in part, on natural gas and LPG. This lack of standards
is seen as a potential barrier to the widespread commercial
introduction of these vehicles into the marketplace due to the
uncertainties the manufacturers face regarding potential future
standards where EPA has not yet addressed any of the issues involved.
In addition, the recent rise in interest in these fuels has resulted in
increased interest in aftermarket conversions (i.e., the conversion of
a vehicle or engine to operate on a fuel other than that for which it
was originally designed and certified to operate). Again, the lack of
defined certification procedures for conversions, as well as the
absence of a method to demonstrate good emissions performance of such
conversions, are seen as potential barriers to their more widespread
use for two reasons. First, the lack of defined certification
procedures leads to uncertainty among converters as to whether the
conversions they perform constitute tampering and result in the
potential associated liability. Second, the potential for environmental
benefits associated with gaseous fuels has led to increased interest in
marketing conversions as an environmental strategy. The lack of a
recognized procedure for confirming emissions performance has been seen
as hindering efforts to market conversions in this manner. Thus, in
order to remove these potential barriers EPA published a Notice of
Proposed Rulemaking (NPRM) proposing emission standards for natural gas
and LPG vehicles, and certification procedures for aftermarket
conversions on November 5, 1992 (57 FR 52912).
A public hearing was held on December 3, 1992, in Ann Arbor,
Michigan at which verbal comments on the NPRM were received. Written
comments responding to the proposal were also received from 34 public
and private parties. The Agency fully considered all comments received
in developing today's final rule.
The remaining sections of this preamble describe EPA's resolution
of the issues associated with the rulemaking. Section II describes
today's action and summarizes the new requirements. Section III reviews
the major comments received on the NPRM and the Agency's analysis of
those comments. Subsequent sections summarize the technical
feasibility, leadtime requirements, environmental effects, and economic
effects associated with today's action.
II. Description of Action
This section describes each provision of today's rule. In general,
today's rule extends the coverage of the existing federal motor vehicle
emissions program to include natural gas and LPG vehicles (hereinafter
referred to as gaseous-fueled vehicles). As such, EPA's current
regulations governing certification, production line, and in-use
requirements are for the most part adopted for gaseous-fueled vehicles.
Rather than present an exhaustive review of the entire federal
emissions program, this section contains a basic description of the
gaseous-fueled vehicle regulations and highlights where these
regulations differ from those currently in place for other vehicles.
For additional information on the new or existing program requirements
the reader is referred to the accompanying regulations appearing at the
end of today's notice, and Title 40, parts 80, 85, 86, 88 and 600 of
the Code of Federal Regulations, which this rulemaking amends.
A. Timing
EPA proposed that these standards be effective with the 1994 model
year, and explained that the Agency did not expect that significant
lead-time for developing emission control technology would be required
for compliance. Nonetheless, because this rule is not being promulgated
until after the start of the 1994 model year, EPA no longer believes
that there is sufficient time to certify vehicles and engines pursuant
to these regulations for the 1994 model year. Further, EPA received
several comments stating that leadtime was required for technology
development, especially for durability demonstration, in addition to
that required for the certification process alone. Therefore, EPA is
promulgating the standards to be effective with the 1997 model year.
Finally, the refueling requirements for gaseous-fueled vehicles will be
implemented consistent with the recently finalized refueling emission
standards for other vehicles (three year phase-in beginning with the
1998 model year for light-duty vehicles and the 2001 model year for
light-duty trucks).\1\ The requirements for refueling stations will
take effect on January 1, 1998 for large volume stations, with a two
year delay until January 1, 2000 for those stations which dispense less
than 10,000 gallons per month on a gasoline equivalent basis. This
phase in for smaller stations is consistent with the approach taken
with the dispensing rate limits placed on gasoline refueling stations
contained in the evaporative emissions final rule.\2\
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\1\59 FR 16262, April 6, 1994.
\2\58 FR 16002, March 24, 1993.
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EPA proposed that manufacturers be allowed to certify engines and
vehicles produced prior to the effective model year in order to include
engines in the emissions trading and banking program, and to include
vehicles in manufacturers' corporate average fuel economy. EPA received
no adverse comments on this aspect of the proposal. For this reason,
manufacturers may choose to comply prior to the 1997 model year,
including the 1994 model year.
Including 1994 model year engines in the emissions trading and
banking program and raises an issue whether engines manufactured in
model year 1994 prior to the promulgation of this rule may be included
in the program. A similar situation was confronted in the original
banking and trading rule. There, EPA allowed banking for the full 1990
model year, even though the rule was promulgated on July 26, 1990. See
55 FR 30584, 30587. In that case, EPA placed certain restrictions on
the inclusion of 1990 model year engines, to ensure credits were only
given for significant reductions below the 1990 standards. This was to
ensure that ``windfall'' credits from exceeding the arguably ``lax''
pre-1991 standards would not be used in the transition to the more
stringent 1991 standards. As a result, if no restrictions on trading
and banking were imposed, then the engines that had always exceeded the
1990 standards would for the first time be able to use the extra
reductions as ``windfall'' credits to offset engines that did not yet
meet the new and more stringent 1991 standards. See 55 FR at 30597.
EPA does not believe such restrictions are necessary in this case.
Since 1991, engines using other fuels, such as methanol, have been able
to generate credits to offset higher emitting engines. EPA believes
that gaseous-fueled engines should have an equal opportunity to use
such credits as gasoline-, diesel-, and methanol-fueled engines, now
that emissions standards and test procedures are in place in time for
the 1994 model year. As EPA explained in the response to comments in
the trading and banking final rule, CNG engines were not included at
that time due to the absence of standards, test procedures, and
certification protocols. See id at 30609. Now that these rules are in
place, there is no longer any reason to disadvantage CNG engines vis a
vis other fuels.
In addition, EPA does not believe that the credits manufacturers
might obtain from gaseous-fueled engines are ``windfall,'' since they
arguably would not have manufactured such engines in model year 1994
but for EPA's actions to provide an incentive to do so. Rather, EPA
believes manufacturers had an incentive to manufacture gaseous-fueled
engines based on EPA actions prior to this final rule. EPA proposed
these standards in November 1992, and began developing these standards
substantially before that. EPA believes this overall incentive further
supports allowing manufacturers to include all 1994 model year engines
in the trading and banking program.
The aftermarket conversion certification procedures contained in
today's rule are available to converters as a way of obtaining an
exemption from the tampering prohibition. Since this procedure creates
an exemption and is optional it will be available upon publication in
the Federal Register. EPA's current policy toward conversions will
continue to apply to aftermarket conversions which have not received an
exemption under this new program.\3\
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\3\See March 4, 1993 Fact Sheet available in the public docket.
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The Administrative Procedure Act requires 30 days notice before a
rule may become effective, except under certain circumstances such as
when the rule recognizes an exemption or when the Agency can
demonstrate good cause for immediate effect. The Agency believes it has
good cause for this rule to take immediate effect in the case of the
new vehicle standards since compliance with the new vehicle standards
is optional until well after the 30 day period. In the case of
aftermarket conversions, because this rule creates an exemption from
the tampering prohibition under section 203 of the Act it does not
require 30 days notice, and this exemption will be available upon
publication in the Federal Register.
B. New Vehicle Standards
The new gaseous-fueled vehicle and engine emission standards
contained in today's notice are effective with the 1997 model year.
Optional compliance prior to the 1997 model year is available to
manufacturers who wish to include their vehicles and engines in
emissions averaging, trading and banking programs, as well as the CAFE
program in the case of natural gas-fueled vehicles.
In general, the Agency seeks to control vehicles operated on
alternative fuels so that their emissions are no greater than their
petroleum-fueled counterparts. Thus, the exhaust emission standards for
gaseous-fueled vehicles are numerically equivalent to those which apply
to other, currently regulated vehicles and engines. The only
significant departure from this approach is in the area of hydrocarbon
(HC) standards for natural gas fueled vehicles and engines. Prior to
the 1994 model year, regulated vehicles (i.e., gasoline, petroleum
diesel and methanol) are only required to meet total hydrocarbon (THC)
standards. However, beginning with the 1994 model year, currently
regulated light-duty vehicles and light-duty trucks will also be
required to meet separate nonmethane hydrocarbon (NMHC) standards as
part of the Tier 1 requirements of the Clean Air Act.\4\ For natural
gas-fueled light-duty vehicles and light-duty trucks only the NMHC
standards will apply. In the case of natural gas-fueled heavy-duty
engines, NMHC standards which provide the same degree of NMHC control
as the current THC standards provide for petroleum-fueled vehicles will
apply. In the case of LPG vehicles and engines, the HC standards are
the same as those for currently regulated vehicles. A summary of
today's gaseous-fueled vehicle emission standards is contained in
Tables 1 through 4.
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\4\The Agency uses the phrase ``Tier 1'' to denote the 1994 and
later model year standards in part because they are nearly identical
to the Tier 1 standards prescribed by section 202(g) of the Clean
Air Act for petroleum-fueled vehicles (56 FR 25724, June 5, 1991).
Use of this phrase is not meant to suggest that gaseous-fueled
vehicles are subject to the section 202(g) Tier 1 standards.
Table 1.--Emission Standards for 1997 and Later Model Year Gaseous-Fueled Light-Duty Vehicles (q/mi)1
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Evaporative
Fuel Standards\2\ THC NMHC CO NOX PM\3\ hydrocarbons
(g/test)
----------------------------------------------------------------------------------------------------------------
Intermediate Useful Life Standards\4\
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Natural Gas............ Tier 0............ ......... 0.34 3.4 1.0 0.20 2.0
Natural Gas............ Tier 1............ ......... 0.25 3.4 0.4 0.08 2.0
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LPG.................... Tier 0............ 0.41 ......... 3.4 1.0 0.20 2.0
LPG.................... Tier 1............ 0.41 0.25 3.4 0.4 0.08 2.0
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Full Useful Life Standards\5\
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Natural Gas............ Tier 1............ ......... 0.31 4.2 0.6 0.10 ............
LPG.................... TIer 1............ ......... 0.31 4.2 0.6 0.10 ............
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\1\Crankcase emissions are prohibited. Standards apply at all altitudes. For Tier 1 standards, vehicles are
required to meet both the intermediate and full useful life standards.
\2\The Tier 1 standards apply to 40 percent of a manufacturer's optionally certified 1994 model year vehicles,
80 percent of optionally certified 1995 vehicles, and 100 percent of optionally certified 1996 vehicles. The
Tier 0 standards apply to optionally certified pre-1996 model year vehicles not covered by the Tier 1
standards.
\3\Tier 0 particulate standards apply to diesel-cycle vehicles only. Tier 1 particulate standards apply to all
vehicles.
\4\Five years or 50,000 miles, whichever occurs first.
\5\Ten years or 100,000 miles, whichever occurs first. No full useful life Tier 0 standards.
Table 2.--Emissions Standards for 1997 and Later Model Year Gaseous-Fueled Light Light-Duty Trucks (g/mi)\1\
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Evaporative
Fuel LVW (lb)\2\ Standards\3\ THC NMHC CO NOx PM\4\ Idle CO (% hydrocarbons
conc.) (g/test)
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Intermediate Useful Life Standards\5\
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Natural Gas........................... 0-3750 Tier 1...... ........... 0.25 3.4 0.4 0.08 .......... ............
Natural Gas........................... 3751-5750 Tier 1...... ........... 0.32 4.4 0.7 0.08 .......... ............
LPG................................... 0-3750 Tier 1...... ........... 0.25 3.4 0.4 0.08 .......... ............
LPG................................... 3751-5750 Tier 1...... ........... 0.32 4.4 0.7 0.08 .......... ............
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Full Useful Life Standards\6\
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Natural Gas........................... 0-3750 Tier 0...... ........... 0.67(0.83) 10(14) 1.2 0.26 0.50 2.0(2.6)
Natural Gas........................... 0-3750 Tier 1...... ........... 0.31 4.2 0.6 0.10 0.50 2.0(2.6)
Natural Gas........................... 3751-5750 Tier 0...... ........... 0.67(0.83) 10(14) 1.7 0.13 0.50 2.0(2.6)
Natural Gas........................... 3751-5750 Tier 1...... ........... 0.40 5.5 0.97 0.10 0.50 2.0(2.6)
LPG................................... 0-3750 Tier 0...... 0.80(1.0) .......... 10(14) 1.2 0.26 0.50 2.0(2.6)
LPG................................... 0-3750 Tier 1...... 0.80 0.31 4.2 0.6 0.10 0.50 2.0(2.6)
LPG................................... 3751-5750 Tier 0...... 0.80(1.0) .......... 10(14) 1.7 0.13 0.50 2.0(2.6)
LPG................................... 3751-5750 Tier 1...... 0.80 0.40 5.5 0.97 0.10 0.50 2.0(2.6)
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\1\Crankcase emissions are prohibited. Standards in parenthesis apply to vehicles sold in specified high-altitude counties. For the Tier 1 standards,
vehicles are required to meet both the intermediate and full useful life standards.
\2\Loaded vehicle weight (i.e., curb weight plus 300 lb.).
\3\The Tier 1 standards apply to 40 percent of a manufacturer's optionally certified 1994 model year vehicles, 80 percent of optionally certified 1995
vehicles, and 100 percent of optionally certified 1996 model year vehicles. The Tier 0 standards apply to optionally certified pre-1996 model year
vehicles not covered by the Tier 1 standards.
\4\Tier 0 particulate standards apply to diesel-cycle vehicles only. Tier 1 particulate standards apply to all vehicles, but are phased in beginning one
year later than the other Tier 1 standards.
\5\Five years or 50,000 miles, whichever occurs first.
\6\For Tier 0 standards eleven years or 120,000 miles, whichever occurs first. For Tier 1 standards ten years or 100,000 miles, whichever occurs first.
Table 3.--Emissions Standards for 1997 and Later Model Year Gaseous-Fueled Heavy Light-Duty Trucks (g/mi)\1\
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Idle CO Evaporative
Fuel Weight\2\ Standards\3\ THC NMHC CO NOX PM\4\ (% hydrocarbons
conc.) (g/test)
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Intermediate Useful Life Standards\5\
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Natural Gas.................................. 3751-5750.... Tier 1 ........... 0.32 4.4 0.7 ....... ....... ............
Natural Gas.................................. >5750........ Tier 1 ........... 0.39 5.0 1.1 ....... ....... ............
LPG.......................................... 3751-5750.... Tier 1 ........... 0.32 4.4 0.7 ....... ....... ............
LPG.......................................... >5750........ Tier 1 ........... 0.39 5.0 1.1 ....... ....... ............
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Full Useful Life Standards\6\
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Natural Gas.................................. 0-3750....... Tier 0 ........... 0.67(0.83) 10(14) 1.2 0.26 0.50 2.0(2.6)
Natural Gas.................................. >3750........ Tier 0 ........... 0.67(0.83) 10(14) 1.7 0.13 0.50 2.0(2.6)
Natural Gas.................................. 3751-5750.... Tier 1 ........... 0.46 6.4 0.98 0.10 0.50 2.0(2.6)
Natural Gas.................................. >5750........ Tier 1 0.56 7.3 1.53 0.12 0.50 2.0(2.6)
LPG.......................................... 0-3750....... Tier 0 0.80(1.0) 10(14) 1.2 0.26 0.50 2.0(2.6)
LPG.......................................... >5750........ Tier 0 0.80(1.0) 10(14) 1.7 0.13 0.50 2.0(2.6)
LPG.......................................... 3751-5750.... Tier 1 0.80(1.0) 0.46 6.4 0.98 0.10 0.50 2.0(2.6)
LPG.......................................... >5750........ Tier 1 0.80(1.0) 0.56 7.3 1.53 0.12 0.50 2.0(2.6)
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\1\Crankcase emissions are prohibited. Standards in parentheses apply to vehicles sold in specified high-altitude counties. For the Tier 1 standards,
vehicles are required to meet both the intermediate and full useful life standards.
\2\For Tier 0 standards the weight classification is loaded vehicle weight (i.e., curb weight plus 300 lb). For Tier 1 standards the weight
classification is adjusted loaded vehicle weight (i.e., the average of curb weight and gross vehicle weight).
\3\The Tier 1 standards apply to 50 percent of a manufacturer's optionally certified 1996 model year vehicles, and 100 percent of 1997 and later
vehicles. The Tier 0 standards are optional before the 1995 model year and apply to optionally certified 1995 and 1996 model year vehicles not covered
by the Tier 1 standards.
\4\The Tier 0 particulate standards apply to diesel-cycle vehicles only. The Tier 1 particulate standards apply to all vehicles, but are phased in
beginning one year later than the other Tier 1 standards.
\5\Five years or 50,000 miles, whichever occurs first.
\6\Eleven years or 120,000 miles, whichever occurs first.
Table 4.--Emissions Standards for 1997 and Later Model Year Gaseous-Fueled Heavy-Duty Engines g/BHP-hr\1\
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Idle CO Evaporative
Fuel Combustion GVW THC NMHC CO NOX\2\ PM (% hydrocarbons
cycle conc.) (g/test)
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Natural Gas.......................................... Otto......... 8501-14000 ....... 0.9 14.4 5.0 ....... 0.50 3.0
Natural Gas.......................................... Otto......... >14000 ....... 1.7 37.1 5.0 ....... 0.50 4.0
LPG.................................................. Otto......... 8501-14000 1.1 ....... 14.4 5.0 ....... 0.50 3.0
LPG.................................................. Otto......... >14000 1.9 ....... 37.1 5.0 ....... 0.50 4.0
Natural Gas.......................................... Diesel....... 8501-14000 ....... 1.2 15.5 5.0 \3\0.10 0.50 3.0
Natural Gas.......................................... Diesel....... >14000 ....... 1.2 15.5 5.0 \3\0.10 0.50 4.0
LPG.................................................. Diesel....... 8501-14000 1.3 ....... 15.5 5.0 \3\0.10 0.50 3.0
LPG.................................................. Diesel....... >14000 1.3 ....... 15.5 5.0 \3\0.10 0.50 4.0
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\1\g/BHP-hr = grams per brake horsepower hour. Crankcase emissions are prohibited beginning with the 1998 model year.
\2\The NOX standard is 4.0 g/BHP-hr for all 1998 and later model year HDEs.
\3\For optional compliance prior to the 1997 model year this standard is 0.10 g/BHP-hr for the 1994 and later model year, except for urban bus engines.
For urban bus engines the optional standards are 0.07 g/BHP-hr for the 1994 and 1995 model years, and 0.05 g/BHP-hr for the 1996 model year. The
required standard for 1997 and later model year urban bus engines is 0.05 g/BHP-hr.
For the purposes of these standards, the current scheme of
classifying vehicles as either Otto-cycle or diesel is being extended
to gaseous-fueled vehicles, with some modifications as described below.
This classification scheme was promulgated with the methanol standards
to group engines regardless of fuel type in a manner that would provide
equivalent control.
Although there are other factors to consider, in general an Otto-
cycle engine is considered to be one that is throttled during normal
operation whereas a diesel is not. The Agency recognizes, however, that
in some cases this criterion may not be adequate or appropriate to
determine a vehicle's classification. For example, a gaseous-fueled
engine which is derived from a particular Otto-cycle or diesel base
engine, and is expected to be used in similar applications as the base
engine, would most appropriately be classified the same as the base
engine from which it was derived. In such cases the Administrator will
take into account other relevant factors, such as compression ratio,
combustion and thermodynamic characteristics, or intended in-use duty
cycle when classifying the vehicle.
Today's rule establishes the same evaporative emission requirements
for gaseous-fueled vehicles which were recently adopted for other
vehicles.\5\ The Agency recognizes that due to the sealed nature of
gaseous-fueled vehicle fuel systems, emissions of unburned fuel from
the fuel system are expected to be near-zero. However, the evaporative
requirements are being adopted to assure leak-free fuel systems.
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\5\58 FR 16002, March 24, 1993.
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Today's rule establishes refueling requirements for gaseous-fueled
light-duty vehicles and light-duty trucks, as well as refueling
stations. Natural gas-fueled vehicles must be equipped with a refueling
receptacle which meets the requirements of the recently adopted ANSI/
AGA NGV1 standard for refueling couplings. Natural gas refueling
stations will not be allowed to vent more than 1.2 grams natural gas
due to refueling nozzle disconnect. The applicable dates for these
standards are discussed in the timing section of today's rule.
For LPG vehicles there are two requirements. First, all LPG vehicle
refueling stations will be required to use nozzles which have very low
dead volume (2.0 cm\3\) from which fuel would be vented upon nozzle
disconnect. This requirement was derived from the recently promulgated
onboard refueling vapor recovery standard. For a complete description
of the derivation please consult the summary and analysis of comments
document. Second, LPG-fueled light-duty vehicles and light-duty trucks
will be subject to the onboard refueling emission standards, adjusted
for the difference in LPG energy density as compared to gasoline. This
adjusted standard is 0.15 grams per gallon of LPG dispensed. The
applicable dates for these standards are discussed in the timing
section of today's rule. Additionally, for any LPG vehicle that
contains a fixed liquid level valve (i.e., ``outage valve''), the
refueling test will be performed with the liquid level valve in the
open position unless the manufacturer can demonstrate to the
satisfaction of the Administrator, that the fixed liquid level gauge
would not be opened during refueling in ordinary use due to
inaccessibility or other reasons.
EPA recognizes that, although it did propose the control of
refueling emissions from gaseous-fueled vehicles, the proposal did not
include specific numerical standards as contained in today's rule.
However, EPA believes that this action will be noncontroversial, and
the Agency anticipates no significant comments regarding it.
Nonetheless, the public is advised that these elements of today's
action dealing with refueling emissions will be effective 60 days from
the date of this Federal Register notice, unless notice is received
within 30 days that interested parties wish to submit adverse or
critical comments on that element of this action. If such notice is
received, this action will be withdrawn and two subsequent notices will
be published. One notice, which would be published before the effective
date, will withdraw the final action. Another notice will begin a new
rulemaking by announcing a proposal of the action and establishing a
comment period.
There is reason to believe that, in the case of some of the above-
mentioned pollutants and vehicle classes, the levels of emissions will
normally be substantially below the levels of the applicable standards.
In such cases today's rule includes provisions for a waiver of
certification testing requirements which allow a manufacturer to
certify the vehicle or engine without performing the actual
certification testing for which a waiver has been granted, similar to
the waivers available for heavy-duty diesel engine CO, methanol vehicle
and engine smoke and particulate, and Otto-cycle light-duty vehicle and
light-duty truck particulate standards.\6\ A certification testing
waiver can be obtained by demonstrating that, by virtue of a vehicle's
design, it will always meet the standard for which the waiver was
granted. This demonstration can be in the form of development testing
data or other engineering data. It should be noted that these waivers
only apply to certification testing requirements and do not relieve the
manufacturer of liability for meeting the standard. Vehicles which have
been certified using these waiver provisions also remain subject to
selective enforcement audit (SEA) and in-use testing. The waivers
provided in today's rule are available for all gaseous-fueled vehicle
evaporative and refueling standards, gaseous-fueled heavy-duty diesel
CO (including idle CO), particulate and smoke standards, and
particulate standards for light-duty vehicles and light-duty trucks.
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\6\47 FR 49811, November 2, 1982; 54 FR 14426, April 11, 1989;
and 56 FR 25724, June 5, 1991.
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Today's rule allows gaseous-fueled vehicles to demonstrate
compliance with emission standards through averaging, trading and
banking in the same manner as vehicles operated on other fuels.
Gaseous-fueled vehicles will be treated similarly to methanol-fueled
vehicles with respect to the constraints of the various programs. For a
more detailed discussion of how gaseous-fueled vehicles fit into these
programs please consult the public docket for this rulemaking.\7\ As
explained above, in addition to new vehicles and engines, today's rule
allows manufacturers to include in the averaging, trading and banking
programs 1994 model year vehicles and engines manufactured before the
rule's effective date, but identical to 1994 model year vehicles and
engines manufactured after the effective date.
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\7\Public docket A-92-14, item III-B-2.
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Today's rule delays the applicability of federal on-board
diagnostics (OBD) requirements for natural gas-fueled light-duty
vehicles and light-duty trucks until the 1998 model year. As finalized
in the February 19, 1993 OBD rule\8\ those requirements were scheduled
to take effect with the 1994 model year for all vehicles for which
emission standards exist. However, due to the feasibility issues unique
to natural gas-fueled vehicles, these requirements are being delayed
until the 1998 model year. OBD I requirements will apply to natural gas
vehicles in the 1997 model year, as well as those natural gas vehicles
optionally certified prior to the 1997 model year. The OBD requirements
contained in the OBD rule will apply to liquefied petroleum gas-fueled
light-duty vehicles and light-duty trucks beginning with optionally
certified vehicles in the 1994 model year.
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\8\58 FR 9468, February 19, 1993.
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C. Certification Test Fuel Specification
The certification test fuels in today's rule are intended to
represent the actual fuels gaseous-fueled vehicles are likely to see
in-use. Given the wide range of in-use fuel compositions, the
certification fuels are broadly defined. In the case of natural gas,
the certification fuel specifications include a minimum methane content
of 89 percent, as well as maximum levels for the other prominent
hydrocarbons found in natural gas (e.g., ethane, propane).
Certification fuel under this approach reflects over 90 percent of the
natural gas available in the United States. Most of the gas not meeting
this criteria is gas being sold in high altitude areas, where higher
levels of inert gases are added to the natural gas.
Significantly less is known about the variability of in-use LPG
composition. However, the Agency believes that the composition of LPG
is more consistent than that of natural gas due to common carrier
pipeline and import tariff constraints. Thus, the Agency is adopting
commercially available LPG as the certification fuel for LPG vehicles.
As more information becomes available on LPG composition, and as
experience with LPG vehicles increases, the need for a more well-
defined LPG certification fuel may become apparent. Should this happen,
EPA would take steps at that time to develop an appropriate LPG
certification fuel specification. It should be noted that the Agency is
not including any controls on in-use natural gas or LPG in today's
rule, but intends to monitor in-use fuels to ensure that the
certification fuels remain representative.
D. Test Procedures
For the most part, the current test cycles, and measurement and
analytical procedures can be directly applied to gaseous-fueled
vehicles. Thus, the test procedures contained in today's rule are
largely the same as those which apply to other, currently regulated
vehicles. The only exception of note is the procedure for measuring
NMHC emissions from natural gas-fueled vehicles. The current procedure
for measuring NMHC emissions was adopted in the Tier 1 rule.\9\ While
this procedure works fairly well for currently regulated vehicles, it
is not nearly as accurate for natural gas-fueled vehicles due to their
much higher levels of exhaust methane. Thus, today's rule contains some
slight modifications to the NMHC test procedures adopted for the Tier 1
standards\10\ to allow more accurate NMHC measurement from natural gas-
fueled vehicles. These changes include accounting for the different
flame ionization detector (FID) response to methane as opposed to the
other hydrocarbons, as well as the use of fuel densities and H/C ratios
in the calculations which are more appropriate to natural gas vehicles.
The Agency views this as an interim measure and is currently working
with the California Air Resources Board and the American Automobile
Manufacturers Association as part of a cooperative research and
development agreement to develop a more accurate procedure for the
direct measurement of NMHC.
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\9\56 FR 25724, June 5, 1991.
\10\56 FR 25724, June 5, 1994.
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E. Fuel Economy
Today's rule contains fuel economy test procedures and calculations
for measuring the fuel economy of natural gas-fueled light-duty
vehicles and light-duty trucks. The driving cycles adopted for natural
gas vehicles are the same as those currently in place for gasoline-
fueled vehicles. Also, the measurement and calculation procedures for
natural gas vehicles rely on the same principle of carbon balance as
the current gasoline procedures, but include a gasoline/natural gas
equivalency factor of 100 standard cubic feet of natural gas equalling
0.823 gallons of gasoline.
These procedures and calculations will allow these vehicles to be
included in a manufacturer's corporate average fuel economy (CAFE)
under the Motor Vehicle Information and Cost Savings Act (MVICSA), 15
U.S.C. Sec. 2001 et seq. The Alternative Motor Fuels Act of 1988,\11\
provides that alternative fueled vehicles (including natural gas-fueled
vehicles) may be included in a manufacturer's CAFE calculation on a
favorable basis in order to encourage the manufacture of such vehicles.
The AMFA provides that, for purposes of including natural gas vehicles
in the CAFE calculation, fuel consumption of natural gas vehicles is
only fifteen percent of equivalent gasoline fuel consumption. The AMFA
also mandates the 0.823 gasoline/natural gas equivalency factor
included in today's rule. Regulations governing the calculation and use
of natural gas vehicle CAFE credits are contained in a separate
rulemaking action.\12\
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\11\Public Law 100-494, October 14, 1988.
\12\56 FR 8856, March 1, 1991.
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As will be discussed further in the Public Participation section of
this rule, the Agency is not promulgating fuel economy procedures for
LPG vehicles today, but will do so in a separate rulemaking action.
F. Aftermarket Conversions
Today's rule contains provisions for the certification of
aftermarket conversions (i.e., conversions which allow a vehicle or
engine to operate on a fuel other than the fuel for which it was
originally designed and certified). An exemption from the tampering
prohibitions contained in section 203(a)(3) of the Clean Air Act can be
secured through this certification process. The provisions contained in
today's rule for securing such an exemption consist of three main
parts: applicable standards, test procedures, and warranty/liability
issues.
It has always been the Agency's policy that an aftermarket
conversion not degrade the emissions performance of the original
vehicle as a condition of being exempt from prosecution for tampering
violations. Today's rule merely clarifies that policy by providing
specific procedures by which one can certify that a conversion does
meet this requirement, and thus secure an exemption from the tampering
prohibition. Consistent with this policy, the emission standards which
an aftermarket conversion shall meet in order to secure the tampering
prohibition exemption are essentially the same standards the original
vehicle was certified as meeting. In the case of conversions to natural
gas, the converted vehicle would not be required to meet the THC
standard, but must meet an NMHC standard which provides an equivalent
amount of NMHC control as that afforded by the original THC standard.
In the case of conversion to multi-fuel operation (i.e., where the
vehicle has the ability to switch between two fuels, such as gasoline
and natural gas, or where the vehicle operates on two fuels
simultaneously, but retains the ability to operate exclusively on the
original fuel), the vehicle would still be required to meet the
emission standards it was originally certified to when operating on the
original fuel, in addition to meeting the applicable requirements on
the new fuel.
The test procedures applicable to aftermarket conversions under
this program are those currently in place new vehicle certification as
outlined in 40 CFR Part 86. The small volume manufacturers
certification program contained in 40 CFR 86.092-14 is also available
for aftermarket conversion certification provided the company or
individual seeking certification meets the sales limits described in
that section. These procedures utilize the same test cycles and
analytical procedures that are used for new vehicle certification. In
the case of aftermarket conversions a certificate of conformity must be
sought for each engine family/conversion system combination and for
each model year vehicle for which the system is intended.
As a condition of exemption from the tampering prohibition,
conversion manufacturers and installers must accept in-use liability
for warranty and recall as outlined in section 207 of the Act and its
implementing regulations.\13\ This is consistent with EPA's policy that
aftermarket conversions not degrade the emissions performance of the
original vehicle. It will also assure that the conversion will meet the
applicable emission standards throughout its useful life. Since
conversions generally rely, at least in part, on emission control
equipment already on the original vehicle for emissions control, the
useful life of a conversion will not extend beyond the useful life of
the original vehicle.
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\13\Code of Federal Regulations, Title 40, Part 86.
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G. Fees
Under section 217 of the Clean Air Act, EPA may establish fees to
recover all reasonable costs incurred for activities associated with
the Motor Vehicle and Engine Compliance Program (MVECP). The MVECP
includes all compliance and enforcement activities performed by EPA
which are associated with certification, fuel economy, Selective
Enforcement Auditing (SEA), and in-use compliance activities. In July
of 1992 EPA established these fees, to be effective with the 1993 model
year.\14\ These fees, as stated in the fees rule, cover all direct and
indirect costs incurred by EPA for the MVECP, and automatically apply
to gaseous-fueled vehicles and engines now that the MVECP applies to
such vehicles and engines. Since the fees are based on the costs
incurred by EPA, and since today's regulations are basically an
extension of the current MVECP, the fees currently in effect for other
vehicles apply to gaseous-fueled vehicles, without modification. No
regulatory changes are needed and none are being made. The applicable
fee must be paid, for each engine family, before the Certification
Division can begin a review of the application for certification.
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\14\57 FR 30044, July 7, 1992.
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III. Public Participation
A number of interested parties commented on EPA's November 5, 1992
NPRM. The comments include written submittals to the rulemaking docket
and those presented at the December 3, 1992 public hearing, which was
held in Ann Arbor, Michigan. The Agency has fully considered these
comments in developing today's final rule.
This section describes the major issues of the rulemaking, as
reflected in the public comments. The discussion of each issue opens
with a brief description of what was proposed followed by a summary of
the significant comments and EPA's analysis of the issue. The reader is
referred to the Summary and Analysis of Comments document for the
complete details of EPA's analysis. That document is available in the
rulemaking docket. (For information on access to the docket, see the
``Addresses'' section above.)
A. Timing of Requirements
Summary of the proposal: As was stated in the NPRM, the Agency
believes that the proposed standards are not technology-forcing, and
that they could be met largely through currently available technology.
Thus, the only leadtime requirement for meeting the proposed standards
would be that of actually going through the certification process
itself, including the required durability showing. The Agency,
therefore, proposed that the new vehicle emission standards be
effective with the 1994 model year, and that the aftermarket
conversions take effect on January 1, 1994. Additionally, the Agency
proposed that manufacturers have the option of complying with these
standards prior to the effective date in order to participate in any
applicable emissions averaging, trading and banking programs, as well
as the CAFE program in the case of natural gas-fueled light-duty
vehicles and light-duty trucks.
Summary of the comments: In general, the comments received in
response to the issue of leadtime supported EPA's assessment that these
standards are not technology-forcing in the sense that fundamentally
new technology must be developed. However, a number of commenters
raised concerns that, although the basic technology required to meet
these standards has been demonstrated at low mileage, the durability of
this technology in many cases remains to be proven. Additionally, one
commenter pointed out that there are several mandated requirements
taking effect in the next few years for new vehicles, including Tier 1
and cold CO standards, on-board diagnostics, and revised evaporative
procedures, and that mandating gaseous-fueled vehicle certification
with little leadtime may seriously impair the introduction of these
vehicles into the marketplace. Most commenters suggested that, given
the need for technology refinement and durability work, these
requirements should not take effect until the 1996 or 1997 model year.
In addition, the heavy-duty engine manufacturers asserted that, under
section 202(a)(3)(C) of the Clean Air Act, EPA is required to provide
four years leadtime in the case of any new emission standards. In most
cases commenters stated that, regardless of what effective date EPA
finalizes, they support the option of being able to certify prior to
the effective date.
EPA response to comments: The Agency agrees that, while current
gaseous-fueled vehicle technology is generally capable of meeting the
emission standards contained in today's rule, work remains in some
cases to meet the durability requirements. While the Agency believes
that some current gaseous-fueled engine technologies are capable of
demonstrating the required emissions durability, it does not believe
this is the case with some of the newest technologies being developed.
Given that each engine family must demonstrate durability during the
new vehicle certification process, the Agency believes that not
providing adequate leadtime may hinder the further development of new
gaseous-fueled vehicle technology in the short term, which is contrary
to the stated intent of this rule. Thus, today's requirements for new
vehicles and engines will take effect with the 1997 model year as
requested by some commenters. Manufacturers will have the option to
comply with these provisions prior to the 1997 model year if they
choose.
The Agency does not believe that this amount of leadtime will be a
problem from an environmental standpoint for two reasons. First, the
volume of new gaseous-fueled vehicles produced prior to the 1997 model
year is not expected to be that large, given the relatively young
nature of the new gaseous-fueled vehicle market. Second, the Agency
expects that any new vehicle or engine family which might be sold in
any significant volume prior to the 1997 model year would have
demonstrated adequate durability. Since there is much incentive for
early compliance in the form of CAFE credits and the emissions banking
and trading program, the Agency would expect the manufacturers of these
vehicles to certify them in order to take advantage of these credits.
Additionally, the Agency does not believe that it is required to
provide four years leadtime for new gaseous-fueled heavy-duty engine
standards because these standards are being promulgated under the
general authority of section 202(a)(1). However, as will be discussed
in the section on CO and crankcase emissions, the Agency has elected to
provide four years of leadtime in the case of crankcase emission
controls. For further discussion of the four year leadtime issue please
consult the summary and analysis of comments document in the docket.
Finally, manufacturers have the option of complying with these
requirements prior to their effective date (including certification
retroactive to the beginning of the 1994 model year) and can include
such certified engines in the averaging, banking and trading program.
B. Standards for HC
1. NMHC vs. THC Standards
Summary of the proposal: Since natural gas is primarily methane,
natural gas-fueled vehicles (NGV) tend to have fairly high levels of
methane emissions in their exhaust HC. Due to the difficulty current
catalyst formulations have in oxidizing methane, it is not currently
feasible for NGVs to meet the same THC standards that other vehicles
meet. Thus, only NMHC standards were proposed for NGVs, with the Agency
deferring any action on THC standards for NGVs until such time as the
necessary methane control technology can be developed. LPG fuel,
however, contains no methane, and the exhaust methane levels associated
with LPG vehicles tend to be much closer to those from petroleum-fueled
vehicles. Thus, all applicable THC and NMHC standards were proposed for
LPG vehicles.
Summary of the comments: The Agency's decision to defer action on
THC standards for NGVs received very broad support. Only the
Manufacturers of Emission Controls Association (MECA) disagreed with
this approach. MECA contended that without some form of technology-
forcing THC standard for NGVs, most work on methane control technology
would likely stop. MECA also pointed out that the Agency has, in the
past, used technology-forcing standards as impetus for the development
of new emission control technology.
Several commenters suggested that the approach of exempting NGVs
from THC standards should be applied to LPG vehicles as well, citing a
potential unfair advantage for NGVs if LPG vehicles were required to
meet THC standards. Additionally, the LP Gas Clean Fuels Coalition
stated that LPG vehicles have substantially higher levels of methane
emissions than their petroleum-fueled counterparts, and thus should
also be exempt from meeting the THC standards. The Coalition, however,
did not submit any data in support of this claim.
EPA response to the comments: The Agency continues to believe that
action on the THC standards for NGVs should be deferred. The Agency
continues to be concerned that compliance with the THC standard
currently in place for other fuels is infeasible for NGVs. While the
Agency has received data suggesting that the THC standards are
technically achievable for NGVs, no data has been submitted concerning
the cost of refining and implementing the necessary technology on a
commercial level. Cost is a component of feasibility, and without cost
information the Agency cannot conclude that compliance with the THC
standards is feasible. Moreover, technical issues remain to be
resolved. The data suggesting that THC standards are technically
achievable was limited to vehicles operating at a stoichiometric fuel/
air ratio, and operation under other conditions (i.e., lean burn)
remains an issue. Additionally, the durability of methane-specific
catalysts remains an unknown.
Also, for the reasons explained in the proposal, EPA does not
believe it can establish a technology-forcing standard. EPA continues
to believe that the amount of lead-time required for adequate
technology development still cannot be readily determined, because the
durability of a methane catalyst formulation has not been established.
EPA does not agree that the absence of a technology-forcing standard
would bring work on methane control technology to a stop. The engine
manufacturing industry has indicated that its research will continue
based on the belief that THC standards will be imposed in the future.
Also, as noted in the proposal, EPA believes that strong growth in the
NGV market in the near-term is important to provide resources for
technology development. Of course, EPA will continue to monitor work on
methane catalyst development. If information becomes available
establishing the technology's feasibility (including cost information),
EPA will consider adopting THC standards for NGVs. Also, if future
events further demonstrate the need for a technology-forcing standard,
EPA will further consider this option as well.
As was stated in the NPRM, the Agency believes it most appropriate
to, wherever possible, apply the same standards to alternative-fueled
vehicles that apply to their petroleum-fueled counterparts. In the case
of NGVs there are circumstances, as discussed above, which justify
deviating from this basic philosophy. However, the Agency has seen no
emissions data which would suggest that a similar set of circumstances
exists for LPG vehicles. Thus, LPG vehicles will be required to meet
the same THC standards as currently apply to other vehicles.
2. Heavy-Duty NMHC Standards
Summary of the proposal: In setting NMHC standards for natural gas-
fueled heavy-duty engines (HDE), the Agency intends to establish
standards which would provide the same level of NMHC control as the THC
standards in effect for petroleum diesel and gasoline HDEs. In the
absence of speciated exhaust HC data on HDEs (i.e., data on the level
of the individual HC components in the exhaust), EPA applied the
results of an analysis done on light-duty vehicles and light-duty
trucks to arrive at NMHC standards which were 82.5 percent of the level
of the corresponding THC standards. The resultant standards were very
close to those adopted by the California Air Resources Board (CARB),
and in the NPRM the Agency requested comment on whether it should adopt
CARB's standards instead.
Summary of the comments: Every commenter who expressed an opinion
on this issue urged EPA to adopt the CARB standards in order that the
California and federal standards be harmonized.
EPA response to the comments: The Agency believes that the
differences between its proposed NMHC standards and CARB's are so small
as not to be an air quality issue. Further, EPA has learned since the
NPRM that the CARB standards were based on speciated data from HDEs.
Thus, as EPA believes that the speciated data provides a sounder basis
than EPA's, the Agency is adopting CARB's NMHC standards for HDEs.
3. Evaporative Emission Standards
Summary of the proposal: In the NPRM it was noted that, due to the
sealed nature of gaseous-fueled vehicle fuel systems, their
``evaporative'' emissions (i.e., emissions of unburned fuel from the
fuel storage system) are expected to be near-zero. Nonetheless, the
Agency proposed evaporative emission controls for gaseous- fueled
vehicles in order to assure that the fuel systems are not leaking. EPA
proposed that the evaporative provisions for gasoline and methanol-
fueled vehicles, which were in the process of being revised at the time
of the proposal for this rule, be applicable to gaseous-fueled vehicles
as well, with modifications to the test procedures as necessary to
accommodate gaseous fuels. The Agency also proposed that certification
testing waivers be available for evaporative testing in order to reduce
the testing burden as much as possible, given the likelihood of near-
zero emissions.
Summary of the comments: Although one commenter supported the
proposed evaporative requirements for gaseous-fueled vehicles, citing
potential fuel leaks from the vehicle refueling receptacle, most of the
comments received expressed opposition. In general, most commenters
said that, for safety reasons, as well as to simply prevent the
complete escape of fuel from the vehicle for economic reasons, the fuel
systems must be sealed. Since sealed systems are a practical
requirement of gaseous-fueled vehicles, they argued, there is no need
for EPA to regulate evaporative emissions. As a result, any
certification testing required would be unnecessary. Some commenters
felt that if EPA were to require some form of evaporative emissions
showing that it should be in the form of an engineering evaluation of
the system, or simply a one hour diurnal test.
EPA response to comments: The Agency agrees with the general
comment that there are practical considerations other than emissions
concerns which force the use of sealed fuel systems on gaseous-fueled
vehicles. As a result, EPA would expect their evaporative emissions to
be near-zero. However, the Agency believes that it is prudent to have
some kind of evaporative emission standard which can be enforced, in
order to assure that fuel system leaks do not become a problem. Thus,
the same new evaporative provisions applicable to other vehicles
beginning with the 1996 model year will also be applied to gaseous-
fueled vehicles at that time, recognizing that compliance with these
standards is optional prior to the 1997 model year. The Agency does
recognize, however, that it is likely that, by virtue of their design,
gaseous-fueled vehicles will emit well below the applicable standards.
Therefore, certification testing waivers will be available for all
gaseous-fueled vehicle evaporative provisions if the manufacturer can
show that, by virtue of the vehicle's design, it will always meet the
applicable standards.
C. Refueling Emission Standards
1. Natural Gas
Summary of the proposal: In the NPRM the Agency proposed that, in
the case of natural gas refueling facilities, no refueling hoses which
need to be vented down prior to disconnect shall be vented to the
atmosphere. Rather, as is the case with many current natural gas
refueling facilities, EPA expects that such vent-down gases should be
routed back to the compressor inlet rather than being vented to the
atmosphere. The timing of this requirement was not explicit in the NPRM
preamble. However, the regulatory text stated that the provisions would
take effect with the 1994 model year.
Summary of the comments: In general, the comments received in
response to the issue of natural gas refueling hose venting opposed, to
some degree, the proposed prohibition on venting emissions. Some
commenters suggested that this requirement is not needed at all given
the extremely small contribution to total methane emissions that vent-
down gases represent. Several commenters pointed out that the upcoming
ANSI/AGA NGV1 standard would address EPA's concerns about refueling
emissions from natural gas refueling stations. One commenter pointed
out that this proposed requirement could be interpreted as a zero-
emission standard and questioned the feasibility of such an approach.
Some commenters suggested that more leadtime was needed than was
proposed. Several commenters pointed out that the cost of controlling
these emissions varied quite a bit depending on the inlet pressure of
the compressor. In cases where the natural gas supply line is at fairly
low pressure (i.e., 15 psi or less) the gas could be routed directly
into the compressor inlet at low cost. However, in cases where the gas
supply pressure is higher, additional compression equipment would be
needed to compress the vent-down gas in order to route it back into the
compressor, raising costs substantially. Also, the cost of such
controls would be much higher for existing installations than for new
stations because existing stations would likely require excavation for
the return line plumbing. Finally, some commenters stated that EPA
should not control natural gas refueling emissions since they are
primarily methane, and the Agency only proposed NMHC standards for
tailpipe emissions.
EPA response to comments: In the NPRM the Agency mentioned that the
natural gas industry was moving toward the establishment of standard
refueling equipment specifications. That effort, known as the ANSI/AGA
NGV1 standard, was recently adopted by the American National Standards
Institute (ANSI) as the standard for natural gas vehicle fueling
connection devices. While in its various draft forms, this standard
contained a provision limiting the amount of natural gas that can be
vented due to nozzle disconnect. This provision was based on the
proposed onboard refueling vapor recovery (ORVR) standard for gasoline-
fueled vehicles of 0.05 grams per gallon of dispensed gasoline.\15\ As
indicated in the draft ANSI standard contained in the public docket for
this rule, the venting provision was deleted from the final ANSI
standard since, at the time of final balloting on the standard, the
ORVR rule had not yet been promulgated. The ORVR final rule was
recently promulgated and included a gasoline-fueled vehicle refueling
emission standard of 0.20 grams per gallon of dispensed gasoline.\16\
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\15\52 FR 31162, August 19, 1987.
\16\59 FR 16262, April 6, 1994.
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The Agency agrees that a zero-emission standard for natural gas
vehicles is not reasonable and believes that, in its draft form, the
NGV1 standard addressed EPA's concerns with natural gas vehicle
refueling emissions. Thus, the Agency is using the methodology in draft
NGV1 standard to apply the 0.20 gram per gallon refueling standard to
natural gas vehicles. Using this approach, natural gas refueling
stations will be allowed to vent no more than 1.2 grams of natural gas
due to nozzle disconnect. This standard is based on the ORVR standard
of 0.20 grams per gallon of fuel dispensed and a nominal fuel tank
capacity of six gallons gasoline equivalent natural gas, as was assumed
in the draft NGV1 standard. For a more complete discussion of how this
standard was derived please consult the summary and analysis of
comments document for this rule. This requirement will take effect
January 1, 1998 for high volume stations, with a two year extension
until January 1, 2000 for small volume stations (those which dispense
less than the energy equivalent of 10,000 gallons of gasoline per month
based on the AMFA fuel equivalency factor).
In addition to the requirements for natural gas refueling stations,
EPA is also requiring in today's rule natural gas-fueled light-duty
vehicles and light-duty trucks be equipped with refueling receptacles
which comply with the recently adopted ANSI/AGA NGV1 standard. This
requirement will be implemented consistent with the timing of the ORVR
provisions for other vehicles (three year phase-in beginning with the
1998 model year for light-duty vehicles and the 2001 model year for
light-duty trucks). The Agency expects, however, that all new natural
gas- fueled vehicles will have ANSI/AGA NGV1 nozzles long before this
due to the desire for standardized refueling coupling geometry within
the industry.
EPA does not believe that the cost of the refueling station
controls is prohibitive and believes that today's requirement is both
feasible and reasonable. Consistent with this view, most new stations
being installed would meet this requirement. The Agency agrees that in
certain cases, such as those where additional compression equipment is
needed, the cost of retrofitting may not be reasonable. Thus, for in-
use refueling stations which must be retrofitted to meet this
requirement, the Agency will waive the requirement in situations where
the station operator can demonstrate, to the satisfaction of the
Administrator, that compliance with this provision would require the
use of additional compression equipment, or other similar costs. The
impact of such waivers should be minimal given the small number of
stations currently operating, and the small percentage of those
stations which would not currently meet these requirements.
As was discussed earlier, the lack of exhaust THC standards in
today's rule is a function of cost and legal constraints, and the
Agency believes that control of methane is appropriate where it is
feasible and economically reasonable. Thus, EPA does not believe that
the desire to control refueling emissions from natural gas vehicles is
inconsistent with the adoption of exhaust NMHC standards.
2. LPG Vehicle/Pump Interface
Summary of the proposal: Since LPG is transferred in a sealed
system there is little concern about refueling emissions at the
vehicle/pump interface during the actual fuel transfer. Of concern to
the Agency, however, are emissions released when the nozzle is
disconnected from the vehicle. At this point any fuel which is trapped
in the dead space between the nozzle and the vehicle receptacle is
released. In the NPRM the Agency proposed that refueling equipment be
designed so as to prevent this escape of fuel, such as through the use
of low-loss, no-bleed couplings, although no specific numerical
standards were included. As with the natural gas provisions in the
NPRM, the timing of this requirement was not explicit in the NPRM
preamble. However, the regulatory text stated that the provisions would
take effect with the 1994 model year.
Summary of the comments: The Agency received few comments on this
particular aspect of the proposed refueling provisions. The comments
that addressed this issue tended to agree with the need for control.
However, the comments otherwise differed. One commenter suggested that
any hardware requirement be performance-based, rather than
prescriptive, so as to be consistent with EPA's previous consideration
of refueling controls for gasoline vehicles. Also, the lack of a
numerical standard was interpreted as being a zero-emission standard,
which one commenter suggested is infeasible. Another commenter stated
that just requiring new refueling nozzles at all current LPG fueling
facilities would cost about $30 million, but provided no supporting
documentation for that claim.
EPA response to comments: The Agency believes that it is
appropriate to minimize the amount of LPG fuel which is vented from the
dead space between the refueling nozzle check valve and the vehicle
refueling receptacle check valve but also agrees that a zero-emission
standard is unreasonable. Both the nozzle and the vehicle receptacle
geometries play an integral role in the size of this dead space. Thus,
any performance specification for vehicle/pump interface refueling
emissions would have to address the nozzle and receptacle as a single
system. In the case of LPG, there is not a standardized geometry for
refueling nozzles, at least in terms of the parameters which would
affect this dead space. Thus, it is difficult for the Agency to define
a performance specification such as that which has been considered for
gasoline vehicles based upon an industry standard nozzle geometry. The
Agency is aware that the LPG industry is developing nozzles which
dramatically reduce the dead space, especially when used in conjunction
with low-bleed inserts in the vehicle receptacle.
For the reasons just mentioned EPA is finalizing a two-fold
approach to refueling emissions for LPG vehicles. First, today's rule
includes a requirement that LPG refueling nozzles have no more than 2.0
cm3 dead space, as measured from the face of the nozzle which
seals against the vehicle receptacle ``O'' ring. Second, a refueling
standard and SHED-based test consistent with the recently promulgated
ORVR requirement is being adopted for LPG-fueled light duty vehicles
and light-duty trucks. The vehicle standard, adjusted for the
difference in energy density between gasoline and LPG, is 0.15 grams
per dispensed gallon of fuel. This approach will ensure that the LPG
vehicles will have refueling emissions similar to those of other
vehicles meeting the ORVR standards. A certification testing waiver
will be available for all classes of LPG vehicles to which this
standard applies if the manufacturer can demonstrate, through the use
of development or other data, that the vehicle will meet the standard.
For a complete discussion of how the 2.0 cm3 standard for LPG
vehicle refueling nozzles was derived please consult the summary and
analysis of comments document for this rule.
This standard for LPG vehicles will apply to the same classes and
model years as the ORVR rule (i.e., three year phase-in beginning with
the 1998 model year for light-duty vehicles and the 2001 model year for
light-duty trucks). The requirement for the refueling nozzles will take
effect January 1, 1998 for high volume stations, with a two year
extension until January 1, 2000 for small volume stations (those which
dispense less than the energy equivalent of 10,000 gallons of gasoline
per month). The Agency believes that this amount of leadtime for
refueling stations will allow for the replacement or retrofit of LPG
nozzles during the normal course of replacement or repair of in-use
nozzles due to wear.
3. LPG Tank Venting
Summary of the proposal: Fuel tanks for LPG vehicles currently have
a device known as a fixed liquid level valve, or outage valve, at the
proper fill level. This is a small orifice which can be opened during
refueling in order to indicate that, upon the release of liquid from
the valve, the tank is filled and refueling should stop. Although LPG
tanks are now constructed with built-in automatic shutoff devices to
prevent overfilling, they still have outage valves on them. The Agency
proposed a prohibition on all non-safety-related valves on gaseous-
fueled vehicles in order to prevent the emissions of LPG from outage
valves during refueling.
Summary of the comments: The Agency received a variety of comments
expressing concern about the proposal to eliminate outage valves from
LPG vehicles. First, several commenters pointed out that outage valves
are required under the National Fire Protection Association standard 58
(NFPA 58), and that the NFPA code has been adopted by many state and
local fire marshals as the applicable fire code. Second, some
commenters stated that the regulatory language as proposed precluded
the use of all types of valves on gaseous-fueled vehicles, including
such things as manual fuel shutoff valves. Third, some comments were
received expressing concern that this requirement would preclude the
use of liquefied natural gas (LNG) altogether due to the need to
occasionally vent excess pressure from LNG fuel tanks to prevent
overpressurization. Finally, one commenter expressed concern about the
application of this requirement to LPG vehicles already in service and
the possibility of having to retrofit those vehicles.
EPA response to comments: The Agency understands the apparent
conflict between its proposal and the requirements of NFPA 58. EPA
believes that with the newer requirement in NFPA 58 for automatic
shutoff (overfill prevention) mechanisms, the requirement for outage
valves on vehicle fuel tanks is obsolete, and should be removed from
NFPA 58. Due to this conflict, however, the Agency has chosen not to
finalize its proposed requirements prohibiting outage valves, but is
working with the industry and NFPA to have this requirement deleted
from NFPA. While the Agency believes it has the authority to preempt
NFPA 58 as adopted by fire marshals through the adoption of the
proposed requirement to eliminate outage valves, it prefers to work
with the industry to remove that requirement from NFPA 58 before
superseding state and local law through EPA regulation. Given that the
proposed language prohibiting non-safety-related valves is not being
finalized, the other concerns expressed in the comments are alleviated.
While the Agency is not finalizing the proposed requirements
concerning outage valves, they remain a concern as a source of
emissions. This is especially true for LPG vehicles which are intended
to be certified as ILEVs. Thus, for any LPG vehicle, the above-
mentioned refueling test procedure will be performed with the outage
valve opened, unless the manufacturer can demonstrate, to the
satisfaction of the Administrator, that the outage valve or any other
such gauges or valves would not be opened during refueling in-use due
to inaccessibility or other design features that would prevent or make
it very unlikely that they could be opened.
D. Standards for CO and Crankcase Emissions
1. Idle CO
Summary of the proposal: Until the methanol emission standards were
promulgated in 1989, idle CO standards were only applied to Otto-cycle
engines. EPA reasoned that diesel vehicles always operate at such lean
fuel/air ratios that their idle CO emissions would always be well below
the standards. The methanol rule applied idle CO standards to all
methanol-fueled vehicles because the Agency was aware of diesel
methanol vehicles which were throttled at idle. This same reasoning was
applied to gaseous-fueled vehicles, and EPA proposed that idle CO
standards apply to all gaseous-fueled vehicles, not just Otto-cycle
vehicles.
Summary of the comments: The few comments EPA received on this
issue were in opposition to idle CO standards for engines which operate
at lean fuel/air ratios. The commenters stated that lean burn engines
emit very low CO levels, and that there is no need to regulate and test
for emissions which are inherently low.
EPA response to the comments: The Agency recognizes that lean burn
engines do traditionally have much lower CO emissions than vehicles
operating at stoichiometric fuel/air ratios. However, EPA believes that
not enough data yet exists on diesel gaseous-fueled vehicles to justify
their exemption from the idle CO standards. The Agency is especially
concerned about those diesel designs which employ throttling at idle.
It is likely that these vehicles will have no problem meeting the idle
CO standards by virtue of their design and that, this being the case,
the only burden this standard presents is that of the actual
certification testing and reporting. Thus, certification testing
waivers for diesel gaseous-fueled vehicle idle CO standards will be
available to manufacturers that can demonstrate through emissions test
data or other engineering data that a vehicle will, by virtue of its
design, always emit at levels well below that of the applicable idle CO
standard.
2. Crankcase Emissions
Summary of the proposal: Currently, all vehicles and engines, with
the exception of non-naturally aspirated petroleum heavy-duty diesel
engines (HDDE), are prohibited from discharging crankcase emissions
into the atmosphere. The current prohibition is not applicable to non-
naturally aspirated petroleum HDDEs due to concerns that the routing of
oil mist-laden crankcase gases through turbochargers and other air
handling equipment may foul this equipment. With the issuance of the
methanol vehicle emission standards in 1989 this prohibition was
applied to all methanol HDDEs whether they were naturally aspirated or
not. The reasoning was that methanol engine crankcase gases were
expected to be cleaner than petroleum diesel engine crankcase gases,
and closer to gasoline engine crankcase emissions which are been
routinely routed through turbochargers. Given that gaseous-fueled
vehicles are also expected to have cleaner crankcase emissions than
petroleum diesels, this prohibition on crankcase emissions was proposed
to be applicable to all gaseous-fueled vehicles and engines as well,
with no exemption for non-naturally aspirated, gaseous-fueled HDDEs.
Summary of the comments: In general, the comments received in this
area were in opposition to crankcase controls for gaseous-fueled
vehicles and engines. Some commenters suggested that crankcase controls
only be applied to naturally-aspirated gaseous-fueled engines, as is
currently the case with petroleum HDDEs. Others stated that, due to
their inherently low emissions, gaseous-fueled vehicles and engines
should be exempt from all crankcase emission provisions. One commenter
expressed concern about crankcase gases possibly fouling turbochargers,
and then went on to say that gaseous-fueled vehicle crankcase emissions
will be inherently clean and thus do not need to be regulated.
EPA response to comments: In the absence of compelling data showing
that gaseous-fueled vehicle crankcase emissions are cleaner than those
of their petroleum-fueled counterparts, the Agency believes it is
prudent to extend the coverage of the current prohibition on crankcase
emissions to include gaseous-fueled HDDEs. Additionally, EPA believes
that, since the crankcase prohibition for methanol-fueled HDDEs is not
limited to naturally-aspirated engines, as well as the fact that
crankcase emissions are routinely routed through gasoline engine
turbochargers, there is no reason to exempt non-naturally aspirated
gaseous-fueled vehicles and engines from the crankcase emissions
prohibition. As was noted in the leadtime discussion, the Agency
expects that current technology gaseous-fueled engines will be able to
meet these standards, and therefore the minimum amount of leadtime to
allow for certification has been given. However, since turbocharged
gaseous-fueled HDDEs are generally derived from turbocharged petroleum
HDDEs they do not tend to have crankcase emission controls. The Agency
believes that, while the four year leadtime requirement in section
203(a)(3)(C) of the Act is not legally binding in the case of gaseous-
fueled heavy-duty engines, in circumstances where the manufacturers
must make changes to engine designs similar to those made to comply
with changes in gasoline or petroleum diesel requirements, section
203(a)(3)(C) may constitute a proper default period. In order to allow
for the early introduction of gaseous-fueled HDDEs, the Agency is
providing four years leadtime for crankcase controls on turbocharged
gaseous-fueled HDDEs in the absence of factors indicating that another
period is more appropriate. Thus, this provision will take effect for
the 1998 model year. It should be noted that the four years of leadtime
only applies to turbocharged gaseous-fueled HDDEs, and that the
crankcase emission provisions for all other classes of gaseous-fueled
vehicles will take effect with the 1997 model year mandatory
certification, as well as for vehicles and engines certified optionally
prior to the 1997 model year.
E. On-Board Diagnostics
Summary of the proposal: EPA did not specifically address in the
November 5, 1992 proposal the applicability of on-board diagnostics
(OBD) requirements to gaseous-fueled vehicles. This is because the OBD
regulations were not promulgated until after the gaseous-fueled vehicle
standards were proposed.\17\ However, EPA proposed that emission
standards for gaseous-fueled vehicles generally be equivalent to those
for other vehicles. Implicit in that proposal is that gaseous-fueled
vehicles would be required to meet the same OBD requirements as other
vehicles (OBD II or Federal OBD, as applicable by model year).
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\17\58 FR 9468, February 19, 1993.
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Summary of the comments: The Agency received several comments
concerning OBD. These comments fell into two general areas. First,
several commenters requested that the Agency clarify the applicability
of OBD requirements to gaseous-fueled vehicles. Second, comments were
received stating that additional leadtime should be allowed for natural
gas-fueled vehicles to comply with OBD. The OBD provisions as
promulgated require OBD systems to monitor for conditions which would
result in certain increases in THC emissions. The argument for
additional leadtime centered around the fact that natural gas vehicles
will only be subject to NMHC standards while all other vehicles are
subject to THC standards. During the course of the OBD rulemaking
comments were received suggesting that natural gas systems only be
required to measure NMHC emission effects. Commenters argued that the
technology likely to be used to monitor for increases in THC could not
be readily adapted to monitor for increases in NMHC. The Agency
received a comment suggesting that a delay until 1998 would allow
sufficient leadtime to develop the technology needed for natural gas-
fueled vehicles to meet the OBD requirements.
EPA response to comments: The OBD requirements contained in the
February 19, 1993 rule were established pursuant to section 202(m) of
the Clean Air Act. That subsection provides, in pertinent part:
(1) [T]he Administrator shall promulgate regulations under
subsection (a) requiring manufacturers to install on all new light
duty vehicles and light duty trucks diagnostic systems capable of--
(A) accurately identifying * * * emission-related systems
deterioration or malfunction * * * which could cause or result in
failure of the vehicles to comply with emission standards
established under this section.
By its terms, the OBD provision applies only to vehicles for which
emission standards have been established under section 202. The
regulations promulgated on February 19, 1993 simply add a new
requirement that all new light-duty vehicles and light-duty trucks be
equipped with an emission control diagnostic system capable of
identifying emissions-related deterioration and malfunction as detailed
in the regulations.\18\ Therefore, this provision would seem to apply
automatically to gaseous-fueled vehicles as soon as mandatory emissions
standards are established for those vehicles.
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\18\58 FR at 9485; 40 CFR 86.094-17.
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EPA agrees that leadtime until the 1998 model year is necessary for
full implementation of the Federal OBD requirements for natural gas-
fueled vehicles. Therefore, under today's regulations, implementation
of Federal OBD systems will not be required for certification prior to
model year 1998. This is the case for both for voluntary certification
prior to model year 1997, and for mandatory certification in model year
1997. However, consistent with the approach taken in the OBD rule for
vehicles granted a waiver from Federal OBD requirements on feasibility
grounds, natural gas-fueled vehicles certified in the 1997 model year
or optionally prior to the 1997 model year will be required to comply
with OBD I provisions.
EPA believes that allowing leadtime for natural gas-fueled vehicles
until the 1998 model year is legally consistent with sections 202(m)
and 202(a). To be sure, section 202(m)(2) specifically provides that
the required OBD regulations shall take effect in model year 1994,
subject to the Administrator's authority to waiver application of the
regulations for model years 1994 and/or 1995 for any vehicle for which
the Administrator determines the regulations would be infeasible in
those model years. But EPA believes that Congress intended this
effective date provision to apply only to vehicles for which standards
existed at the time of the enactment of the Clean Air Act Amendments of
1990. EPA does not believe that Congress intended this provision to
require OBD to be implemented immediately upon promulgation of any
emission standards under section 202(a)(1) for new kinds of
alternative-fueled vehicles at any point after 1995. EPA cannot adopt
new emission standards for natural gas-fueled vehicles that would
trigger a mandatory OBD requirement that is not feasible. It is also
unreasonable to believe Congress intended that EPA refrain from
establishing mandatory emission standards for natural gas-fueled
vehicles simply because an infeasible OBD requirement would
automatically apply once such standards are established. The Agency's
efforts to ensure that natural gas fueled vehicles' emissions are no
greater than their petroleum-fueled counterparts should not be
frustrated by a concern that compliance with an OBD requirement
requires more leadtime than compliance with the emission standards
themselves.
Rather, EPA believes that the OBD requirements under section
202(m)(1), to be promulgated under section 202(a), incorporate the
general leadtime provision in section 202(a)(2). Section 202(a)(2)
specifically states that ``[a]ny regulation prescribed under paragraph
(1) of this subsection (and any revision thereof) shall take effect
after such period as the Administrator finds necessary to permit the
development and application of the requisite technology, giving
appropriate consideration to the cost of compliance within such
period.'' EPA believes that this leadtime provision applies to all
aspects of new standards established with respect to previously
unregulated alternative-fueled vehicles. EPA agrees with commenters
that leadtime until model year 1998 is necessary for implementation of
Federal OBD systems for natural gas-fueled vehicles. Therefore, Federal
OBD requirements will not apply for certification of such vehicles
until model year 1998; compliance with OBD I provisions is required for
any natural gas-fueled vehicles certified prior to the 1998 model year,
as discussed above.
EPA also recognizes that the current OBD regulations apply to
vehicles subject to a THC standard. As long as only a NMHC standard
applies to natural gas-fueled vehicles, these regulations should
arguably be amended to monitor deterioration and malfunction regarding
NMHC emissions performance. EPA anticipates commencing a rulemaking to
make these changes to the OBD regulations as applicable to natural gas-
fueled vehicles in the near future in time for the changes to apply in
the 1998 model year. This issue does not effect the feasibility of
compliance with OBD I requirements.
As was noted above, the Agency did not formally propose any
specific requirements concerning the applicability of OBD requirements
to gaseous-fueled vehicles. However, the Agency believes that this
issue was fairly raised and sufficiently considered prior to the
promulgation of this final rule since EPA's initial proposal intended
to extend all applicable emission standards to gaseous-fueled vehicles,
and the Agency received several comments on OBD in response to that
proposal. For more discussion of this issue please consult the summary
and analysis document.
F. HC Measurement
Summary of the proposal: The current method for measuring exhaust
NMHC, which was adopted for the Tier 1 tailpipe standards, involves
measuring THC and methane, and subtracting methane from THC to obtain
NMHC. For NGVs the exhaust HC is primarily methane, whereas for other
vehicles the exhaust methane tends to be a much lower percentage of
THC. As a result, the current procedure is much less accurate for NGVs
than for other vehicles, and the need for a better measurement
technique is obvious. The NPRM discussed several potential options for
improved, direct NMHC measurement. However, none of these techniques
was developed sufficiently enough to warrant proposal. Thus, the Agency
proposed, as an interim procedure, some slight modifications to the
current procedure to improve its accuracy for NGVs. Additionally, EPA
proposed that if a better technique had not been developed within the
first two years of these standards' applicability then full gas
chromatograph (GC) analysis would be required. This was intended to
provide the industry with incentive to develop a better alternative
since the inaccuracies of the current procedure clearly preclude it
from being a long term solution.
Summary of the comments: EPA received little comment on this aspect
of the proposal. A few commenters voiced support for the interim
procedure, while some expressed concern over how resource-intensive
full GC analysis would be for routine certification work.
EPA response to comments: The Agency agrees with the commenters
that the modifications to the current procedure constitute the best
interim option, and this is the technique that is contained in today's
rule. Additionally, EPA has entered into a Cooperative Research and
Development Agreement (CRADA) with the California Air Resources Board
and the American Automobile Manufacturers Association to address a
variety of test procedures needs which have arisen out of the Clean Air
Act Amendments. One of the projects the CRADA is addressing is that of
an accurate technique for the direct measurement of NMHC. The Agency
believes that since it is participating in the development process
through the CRADA a technology-forcing approach is not necessary at
this time. Thus, rather than finalize a requirement for full GC
analysis, the best approach would be to continue to work through the
CRADA to develop an NMHC technique which can be adopted as the
certification procedure upon its completion. However, if an appropriate
technique is not developed through the CRADA, EPA will consider a more
accurate procedure such as the GC for the required procedure.
G. Fuel Composition
Summary of the proposal: It is the Agency's belief that
certification test fuels should resemble the fuels that a vehicle is
likely to encounter in-use. Given the wide range of natural gas
compositions currently available throughout the United States, the
Agency proposed very broad specifications for natural gas certification
fuel. These specifications included a range for methane content of 74
to 98.5 percent, as well as broad ranges for several other parameters.
In the case of LPG fuel, much less information is available about
composition variability nationally. Thus, commercially available LPG
was proposed as the certification fuel, with no specific ranges set on
any parameters other than that the primary constituent be propane. The
NPRM contained no provisions for the regulation of in-use composition
of either fuel.
Summary of the comments: Although the Agency received some comments
in support of its proposed certification fuel specifications, in
general commenters believed that the proposed specifications were much
too broad. In terms of natural gas specifications, the comments in
favor of tighter specifications fell into two general categories.
First, several commenters stated that they agreed with EPA's general
approach of a broadly defined specification in order that certification
fuel be representative of in-use fuel. These commenters, however, felt
that the proposed fuel specification was much too broad and encompassed
fuels which could not be considered representative of most natural gas.
Other commenters felt that, in order to be able to meaningfully compare
results from different tests, a very narrowly defined test fuel
specification is needed. Most of these commenters recommended that EPA
adopt the California Air Resources Board (CARB) certification fuel (90%
methane, 1%, among other requirements) as the federal
certification fuel. Some of the commenters who recommended a narrower
range of specifications suggested that EPA adopt a range of
specifications which would allow the use of CARB certification fuel
(e.g., 89% methane, minimum, etc.).
The Agency received little comment on the proposed LPG
certification fuel specifications. A few commenters suggested that EPA
adopt the CARB LPG certification fuel specifications (93.5% propane,
1%, etc.) as the federal certification fuel. Some
commenters agreed with the proposal, stating that it allowed for the
use of butane mixtures in LPG vehicles.
In addition to comments about certification fuel specifications,
several comments were received requesting that the Agency adopt in-use
fuel specifications. These comments generally came from engine and
vehicle manufacturers. These commenters explained that in order to get
maximum emission benefits from gaseous-fueled vehicles it is important
to minimize in-use fuel composition variability. In addition, heavy-
duty diesel engine manufacturers stated that, unlike stoichiometric
engines utilizing oxygen sensor feedback control systems, lean-burn
diesel engines have no way of accounting for fuel composition
variability, and thus may encounter operational difficulties on some
fuels.
EPA response to comments: The Agency both understands and sees the
merits in the arguments for tighter certification fuel specifications.
However, as was previously stated, EPA also believes it is important
that certification fuel be representative of in-use fuel. Thus, in
developing today's final rule the Agency has attempted to find a middle
ground between these seemingly conflicting needs. In the case of
natural gas certification fuel, the Agency is adopting the approach
suggested by some commenters that the specification remain somewhat
broad, but allow for the use of CARB certification fuel. This
specification includes a minimum methane content of 89 percent, among
other parameters. For the complete certification fuel specifications
please see the regulatory text of today's rule. These specifications
were chosen both because they encompass over 90 percent of natural gas
sold in the country and because there was some general support for them
in the comments as a good compromise between EPA's proposed
specifications and CARB certification fuel.
Almost all of the gas not covered by this specification (i.e., gas
with a methane content below 89 percent) is sold in high altitude areas
where the gas tends to contain higher levels of inert gases than that
sold at low altitudes. The Agency believes that excluding high altitude
gas from the specifications should not present a problem for vehicles
which are certified using the 89 percent minimum methane certification
fuel but are operated at high altitudes because, in general, vehicles
which will be certified under the provisions of today's rule are
expected to utilize electronic feedback control systems for proper
management of the fuel/air ratio. The Agency believes that these
systems will be able to account for any differences in fuel composition
between high altitude natural gas and natural gas in the rest of the
country.
It should be noted that, while the natural gas certification fuel
specifications contained in today's rule are much broader than CARB's,
CARB certification fuel does fall within the federal specifications,
and thus could be used for certification testing. For a further
discussion of this issue please consult the summary and analysis of
comments document available in the public docket.
The Agency would like to take a similar approach for LPG
certification fuel as it took for natural gas certification fuel.
However, there is little information available about in-use LPG
composition upon which such a fuel specification could be based. Thus,
EPA believes it prudent to adopt commercial LPG as the certification
fuel at this time. Should adequate information on in-use LPG
composition become available at some point in the future, EPA may elect
to define a certification fuel specification for LPG at that time.
Today's rule contains no controls on in-use fuel composition for
either natural gas or LPG. EPA does not believe that the need for such
in-use controls has been adequately demonstrated. Further, the cost-
effectiveness of such controls is not likely to justify such action.
The Agency is concerned, however, about the possibility of in-use fuel
composition changes over time, and urges the natural gas and LPG
industries to take steps to minimize such variations. Should the in-use
compositions of these fuels change in such a way as to adversely impact
the emissions performance of gaseous-fueled vehicles the Agency would
likely take steps to address the issue at that time, either through
corresponding changes in certification fuel specifications, or possibly
through in-use fuel composition specifications.
H. Fuel Economy
Summary of the proposal: The NPRM included test procedures and
calculations for determining the fuel economy of natural gas-fueled
light-duty vehicles and light-duty trucks for purposes of allowing them
to be included in a manufacturer's CAFE calculation. The proposed
procedures for determining the fuel economy of natural gas vehicles
(NGV) utilize the same principles as those used in the procedures
currently in place for gasoline vehicles. Availability of CAFE credits
for NGVs was mandated in the Alternative Motor Fuels Act (AMFA) of 1988
(Public Law 100-494, October 14, 1988), to be effective with the 1993
model year. No CAFE provisions regarding LPG vehicles were proposed.
Summary of the comments: In general, the comments regarding the
CAFE provisions for NGVs were very supportive. Some commenters urged
EPA to quickly finalize this rule in order to assure that CAFE credits
will be available for 1993 model year NGVs. The lack of fuel economy
provisions for LPG vehicles, however, was perceived by many as an
unfair disadvantage for LPG vehicles. Additionally, many commenters
pointed out that the National Energy Policy Act of 1992 mandated the
availability of CAFE credits for LPG vehicles, and urged EPA to
finalize fuel economy test procedures and calculations for LPG
vehicles.
EPA response to comments: The Agency did not propose fuel economy
measurement procedures for LPG vehicles because prior to the National
Energy Policy Act of 1992 the determination of whether LPG vehicles
should be included in the CAFE program was required to be made by the
Secretary of Transportation under the Energy Policy and Conservation
Act (U.S.C. 2001(5)). At the time EPA issued the NPRM for today's
action the Secretary of Transportation had not made a determination to
include LPG vehicles in the CAFE program. The Energy Policy Act
allowing LPG vehicles to participate in the CAFE program was signed
into law just as EPA issued its proposal. Thus, no fuel economy
provisions were proposed for LPG vehicles. There are two reasons why
EPA is not adopting fuel economy provisions for LPG vehicles in this
rule. First, before EPA can adopt fuel economy test procedures and
calculations for LPG vehicles, the U.S. Department of Transportation
(DOT) is required by the Energy Policy Act to determine a fuel
equivalency factor equating gasoline and LPG so that fuel economy can
be calculated on a gasoline gallon- equivalent basis. This fuel
equivalency factor has not yet been set by DOT. Second, the Agency
believes that the required new fuel economy measurement provisions for
LPG vehicles must be subject to public notice and comment. Thus, the
Agency will work with DOT to develop the fuel equivalency factor, and,
upon determination of that factor, will propose LPG fuel economy
provisions in a separate Agency rulemaking action.
I. Aftermarket Conversions
1. Applicability
Summary of the proposal: It is the Agency's policy that, based on
the tampering provisions of section 203(a)(3) of the Act, aftermarket
conversions should not degrade the emissions performance of the vehicle
being converted, and that following a conversion a vehicle should still
meet the emission standards it was originally certified as meeting on
any fuels it is capable of using. Under this policy any conversion
which degrades the emissions performance of the vehicle is considered
tampering. In order to clarify how compliance with this policy can be
demonstrated, the Agency proposed that converters can certify as new
vehicle manufacturers using the current new vehicle certification
procedures applicable to small volume manufacturers. The Agency
requested comment on whether the volume limit of 10,000 units that
currently defines a small volume manufacturer should apply to
conversions as well, or whether, as proposed, the small volume
procedures should apply to all converters, regardless of the conversion
sales volume of the company seeking the certification. These
certification requirements were proposed to apply to all aftermarket
conversions performed or sold after December 31, 1993, regardless of
the class or model year of the vehicle being converted. In the proposal
the Agency stated its belief that this rule would not require any
leadtime for technology development and that the only leadtime required
would be for the actual certification process.
Summary of the comments: In general, the comments received on the
aftermarket conversion provisions were very supportive, with several
commenters expressing the need for such requirements, and none
completely opposed. One commenter suggested that these requirements
should only apply to conversions in areas which are not in attainment
with national ambient air quality standards. Comments were received
both in favor of and opposed to applying the 10,000 limit to the use of
the small volume procedures for conversions. Other comments received
indicated that there was some confusion as to the applicability of the
proposed requirements to conversions done before 1994, as well as to
conversions of pre-1994 model year vehicles performed after December
31, 1993.
EPA response to comments: As was stated in the description of
today's rule, an aftermarket conversion company can choose to comply
with these provisions to obtain an exemption from the tampering
prohibition. Only conversions which are intended to generate some form
of credit, such as clean-fueled fleet vehicle purchase credits, will be
required to comply with these provisions. Converters which choose not
to obtain an exemption from the tampering prohibition under this
procedure will be handled under the current tampering policy. Given
that this is an optional certification procedure for conversions the
issues of leadtime and mandatory start date are less relevant.
The Agency agrees with the comment that the production volume
limits that currently define a small volume manufacturer also apply to
converters seeking to certify as manufacturers under today's program.
The Agency expects that the demand for aftermarket conversions will
grow dramatically over the next few years in response to a variety of
state and federal programs. It seems reasonable to require the larger
conversion companies to undergo full new vehicle certification if they
choose to get an exemption from the tampering prohibition by certifying
as a manufacturer. Thus, the volume limits that currently apply to
manufacturers seeking to certify under the small volume manufacturers
provisions will also apply to converters seeking to certify as
manufacturers. The Agency recognizes that, while the current small
volume manufacturers limit applies to sales for a particular model
year, conversions are routinely performed on older vehicles, and a
conversion company may offer conversion systems for vehicles from
several different model years at any given time. Thus, the 10,000 sales
volume limit for certifying under the small volume manufacturers
procedures will apply to calendar year sales for the purposes of
aftermarket conversions. For a further discussion of how this volume
limit will be applied see the summary and analysis of comments
document.
2. Test Procedures
Summary of the proposal: In the NPRM the Agency proposed using the
same test procedures for conversions that are used for new vehicle and
engine certification. This approach was proposed because the Agency
believes that this is the only way of truly measuring the emissions
performance of a conversion relative to the emission standards
applicable to the original vehicle or engine.
Summary of the comments: Most of the comments received on the issue
of test procedures for aftermarket conversions concerned the
differences between EPA's proposed procedures and those adopted by
CARB. In general, where there are differences between CARB's procedures
and those proposed by EPA the commenters requested that the Agency
adopt the CARB procedures instead of what it proposed. In the case of
procedures for converted light-duty vehicles and light-duty trucks
EPA's proposed test procedures are essentially the same as CARB's.
Thus, there is no issue in the case of light-duty vehicle and light-
duty truck certification procedures for aftermarket conversions.
EPA's proposed procedures for conversions of vehicles whose engines
were originally certified on an engine dynamometer (i.e., most heavy-
duty engines) are quite different than CARB's. As was previously
mentioned, the Agency proposed that conversions in this category be
certified using the test procedure used to certify the original engine.
That procedure is the engine dynamometer-based heavy-duty transient
test. CARB's procedures use the chassis dynamometer-based urban
dynamometer driving cycle for conversions of vehicles 14,000 pounds and
under gross vehicle weight (GVW). For conversions of vehicles greater
than 14,000 pounds GVW, CARB's procedures allow for either steady-state
chassis dynamometer testing or an engine dynamometer test approved by
the CARB Executive Officer. Most of the comments received on this issue
requested that, in order to reduce compliance costs, EPA adopt the CARB
test procedures for aftermarket conversions. One commenter also
suggested that it is unfair to require conversions for heavy-duty
engines to be certified using the heavy-duty transient test because
there are few available testing facilities at which one could get the
required testing done.
EPA response to comments: The Agency continues to believe that the
most appropriate way to determine whether an aftermarket conversion
meets the emission standards that the original vehicle or engine was
certified to is to use the same test procedures that were used in
certifying the original vehicle or engine. As the comments suggest,
this is only an issue for the conversions intended for vehicles
originally certified using the engine dynamometer procedures. While the
Agency understands the concerns voiced by the commenters, it does not
believe that there is an adequate alternative to using the original
test procedures when attempting to demonstrate compliance with the
original standards. In the case of the CARB procedures, CARB uses an
approach whereby compliance is determined by comparing post-conversion
emissions performance with pre-conversion performance, and allowing for
some increase in emissions to account for test to test variability.
Given this approach, it is not nearly as important for CARB to use the
same test procedures that were used to certify the original vehicle
because the standards being certified to are not those the vehicle was
originally certified as meeting. However, by taking this approach it is
possible that an aftermarket conversion which exceeds the original
configuration's emissions standards could be certified, which is in
conflict with the anti-tampering provisions of the Act.
In the case of vehicles over 14,000 pounds GVW, CARB allows the use
of eight mode steady-state testing, using the same pre-conversion,
post-conversion comparison as for vehicles under 14,000 pounds GVW.
Again, the Agency believes that it is possible with this approach to
certify an aftermarket conversion which exceeds the original
configuration's emissions standards. Also, the Agency does not believe
that steady-state testing is appropriate under any circumstances. It is
well-understood that emission control systems can be designed for low
emissions when tested using steady-state test procedures, but provide
little emissions control under real-world, transient conditions.\19\ It
is for this reason that EPA adopted the heavy-duty transient test cycle
in place of the thirteen mode steady state test for all heavy-duty
engine certification, effective in the mid-1980s. Thus, EPA does not
believe that it would be appropriate to adopt the CARB test procedures
for these vehicles. It should be noted that CARB does allow for
alternative test cycles for vehicles over 14,000 pounds GVW, subject to
advance approval from the Executive Officer. It is the Agency's belief
that, given the transient test is the test cycle which these vehicles
would have originally been certified on, it is likely that CARB would
approve its use for conversion certification, thus eliminating the need
for two separate certification procedures for vehicles over 14,000
pounds GVW.
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\19\45 FR 4136, January 21, 1980.
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3. On-Board Diagnostics
Summary of the proposal: The Agency recently adopted requirements,
effective for the 1994 model year and thereafter, which require on-
board diagnostics (OBD) systems on new light-duty vehicles and light-
duty trucks.\20\ The purpose of the OBD system is, in part, to monitor
the performance of a vehicle's emission control systems and signal to
the vehicle operator if a system is malfunctioning. The Agency did not
propose any specific requirements regarding how aftermarket conversions
would interact with new vehicle OBD systems, but required that
converted vehicles remain in compliance with all applicable Clean Air
Act Title II emission requirements.
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\20\58 FR 9468, February 19, 1993.
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Summary of the comments: The Agency only received a few comments on
the issue of aftermarket conversions and OBD. These comments tended not
to be specific, but rather asked the Agency to clarify what the
requirements were for an aftermarket conversion on an OBD-equipped
vehicle. A few commenters suggested that EPA require new vehicle
manufacturers to provide some means of shutting off the OBD system
during alternative fuel operation in order to prevent the system from
storing faulty trouble codes.
EPA response to comments: As explained in the preamble to the
proposed rule, EPA believes that a tampering exemption should be
conditioned upon certification demonstrating that the converted vehicle
has the ability to comply with the applicable emission standards and
will have demonstrated adequate durability. As was mentioned above,
shortly after publication of the proposal for this rule, the Agency
adopted requirements, effective for the 1994 model year, which require
OBD systems on new light-duty vehicles and light-duty trucks.
While the aftermarket conversions proposal did not explicitly make
clear that compliance with the OBD requirements (as well as certain
other title II requirements) must be demonstrated to obtain a
certification, the Agency believes this is implicit in the discussion
of the justification for the exemption. The Agency explained in the
proposal that ``Congress intended to prohibit tampering that would
result in emission noncompliance,'' and that ``[t]he language of the
tampering provisions emphasizes the compliance of the vehicle with the
title II regulations.''
EPA's justification for the exemption for conversions from
tampering restrictions was based on the incongruity of prohibiting
conversions that result in a vehicle meeting emission standards
applicable to vehicles of the fuel type to which the vehicles have been
converted. The OBD requirements, even if not ``emissions standards'' in
the traditional sense, clearly have an underlying emissions control
purpose. And the tampering prohibitions of section 203(a)(3) of the Act
explicitly apply to the disabling of any device ``installed on or in a
motor vehicle or motor vehicle engine in compliance with regulations
under this title. . .'' Disabling an OBD system is clearly prohibited
as tampering. It is therefore not at all clear that EPA would have
authority to provide an exemption from the tampering prohibition for a
conversion that do not meet the same OBD requirements as the vehicle
would have had to meet had it been originally manufactured to operate
on fuel type to which it has been converted.
The logic of the Agency's tampering exemption for aftermarket
conversions thus indicates that the Agency intended that the exemption
be conditioned on compliance with all title II requirements applicable
to the converted vehicle when operating on either fuel. Certainly, even
if the proposal did not specifically make clear that it intended to
require compliance with OBD as a condition for a tampering exemption,
that requirement is a logical outgrowth of the discussion in the
proposal. The comments of interested parties reflect a recognition of
EPA's authority to require compliance with OBD as a condition of the
tampering exemption. These comments demonstrate the adequacy of
notice.\21\
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\21\See Shell Oil Co. v. EPA, 950 F.2nd 741, (Dec. 6, 1991).
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4. Liability
Summary of the proposal: In the NPRM the Agency proposed that, in
order to be exempt from the Clean Air Act's tampering prohibition, the
manufacturers and installers of aftermarket conversions must accept in-
use liability for warranty and recall as outlined in section 207 of the
Act and its implementing regulations.\22\ Additionally, EPA proposed
that the vehicle's original manufacturer remain liable for the in-use
performance of any systems which retain their original purpose
following conversion, except in cases where the failure of such a
system is determined to be caused by the conversion. The Agency
proposed that the useful life of a conversion be the same as that of
the vehicle being converted, and requested comment on whether the
useful life of the conversion should be measured from the time of the
conversion or from the time of the original vehicle's manufacture.
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\22\40 CFR Part 85.
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Summary of the comments: The Agency received a variety of comments
on the proposed liability scheme. In general, commenters agreed on the
need for in-use liability for warranty and recall, but differed on
where or with whom this liability should be placed. Some commenters
suggested that the primary liability should be with the conversion
system manufacturer, and that the installer should only be held liable
for the proper installation of the conversion system. Other commenters
agreed with EPA's proposed liability suggesting both that this approach
would protect the conversion consumer in the event that one party went
out of business, and that it would allow manufacturers and installers
to negotiate risk of failure between them. Comments received on the
issue of liability of the vehicle's original manufacturer for the
proper functioning of original equipment also supported both sides of
the issue, with some commenters suggesting that the original
manufacturer's liability should end at the time of conversion and
others supporting the Agency's proposed approach. Finally, all comments
received on the issue of when the useful life begins were in favor of
reducing the useful life requirement of the conversion by the amount of
the original vehicle's useful life which had already passed at the time
of conversion. These commenters suggested that, because aftermarket
conversions generally depend on the original vehicle equipment to some
extent for emissions performance, it would not be appropriate to
require the conversion to continue meeting applicable emission
standards after the original equipment had exceeded its useful life.
EPA response to the comments: The Agency believes that by holding
the entity which certifies the conversion system liable for the in-use
performance of the converted vehicle it has the greatest chance of
assuring quality conversions which will meet applicable emission
standards throughout their useful lives. If poor installation were a
defense to liability, then certifiers would have no interest in
insuring their installers are competent. Such an approach does not rely
on who manufactures or installs the system, but on who certifies the
system as meeting applicable standards. At the time of vehicle
conversion the system certifier assumes liability for the converted
vehicle's in-use emissions performance. The certifier may elect to have
outside agents conduct installations. However, the certifier will be
solely responsible for the converted vehicle's in-use emission
performance. For this reason the Agency recommends that those
certifiers electing to have outside agents conduct installations work
to assure quality system installation.
EPA believes that it is appropriate to hold the original vehicle
manufacturer liable for the performance of any parts or systems which
retain their original function following conversion. If the failure of
such a part or system could be traced to the conversion then the
liability would lie with the conversion certifier. A good indication of
where the liability lies in such situations would be whether the
failure of a part or system is also occurring in non-converted
configurations of the same vehicle.
The Agency agrees with the comments that it is not appropriate to
extend the useful life of a conversion past that of the original
vehicle, given that conversions generally rely on many original vehicle
components for proper operation. Thus, the applicable useful life of
any conversion will be reduced by the amount of mileage on the vehicle
at the time of conversion (i.e., the useful life of a conversion will
end at the same point that the useful life of the original vehicle
ends).
IV. Environmental Effects
The general goal of today's emission standards is to provide a
level playing field for gaseous-fueled vehicles relative to other
currently regulated vehicles, and to remove a potential barrier to
their commercial production. Thus, this rule is not intended to
generate significant emission reductions beyond those achieved by
vehicles operating on other fuel types. As such, the Agency has not
attempted to accurately quantify the environmental effects of today's
rule. However, there are likely to be some beneficial differences
between the emissions from gaseous-fueled vehicles and conventional
vehicles, including possible benefits in the areas of NMHC, CO and air
toxics, as well as benefits associated with improved aftermarket
conversions. For a complete discussion of these potential benefits
please consult the discussion of environmental effects contained in the
NPRM.\23\
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\23\57 FR 52912, November 5, 1992.
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V. Economic Impacts
The Agency expects the emission standards contained in this rule to
be attainable using emission control technology which is similar to
that used on current vehicles. Indeed, this has been the case thus far
with the vehicles which have shown the ability to comply with the
standards. Thus, EPA expects that the cost of emission controls for
natural gas- and liquefied petroleum gas-fueled vehicles will be
similar to that for current vehicles. There are two instances, however,
where compliance with the standards may be less costly for gaseous-
fueled vehicles than for current vehicles: evaporative emissions, and
exhaust aftertreatment for gaseous-fueled heavy-duty diesel engines.
For a complete discussion of these potential benefits please consult
the discussion of economic impacts contained in the NPRM.\24\
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\24\57 FR 52912, November 5, 1992.
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It is not expected that these regulations will have a significant
impact on the cost of aftermarket conversions of conventional-fueled
vehicles to operate on gaseous fuels. The chief area of change in
response to these regulations will be in the area of durability
improvements. This may involve some increase in cost, but overall the
impacts should be small.
Since the purpose of today's standards is to remove the regulatory
uncertainty associated with gaseous-fueled vehicles and to place them
on an equal footing with other vehicles, and not necessarily to achieve
emission reductions, the Agency does not believe it is appropriate to
perform a cost-effectiveness analysis for these standards. Although the
Agency does expect some emission reductions to result from these
standards, that is not the purpose of these regulations. Thus, the
benefits cannot be readily quantified in terms of pollutant inventory
reductions, nor is it appropriate to do this. For these reasons no cost
effectiveness analysis was performed.
VI. Statutory Authority
Authority for the actions in this rule is granted to EPA by
sections 202, 203 and 301(a) of the Clean Air Act (42 U.S.C. 7521 and
7601(a)).
VII. Executive Order 12866
Under Executive Order 12866,\25\ the Agency must determine whether
the regulatory action is ``significant'' and therefore subject to
Office of Management and Budget (OMB) review and the requirements of
the Executive Order. The Order defines ``significant regulatory
action'' as one that is likely to result in a rule that may:
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\25\58 FR 51735, October 4, 1993.
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(1) have an annual effect on the economy of $100 million or more or
adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local or tribal governments or communities;
(2) create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;
(3) materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs or the rights and obligations of recipients
thereof; or
(4) raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
Pursuant to the terms of Executive Order 12866, OMB has notified
EPA that it considers this a ``significant regulatory action'' within
the meaning of the Executive Order. EPA has submitted this action to
OMB for review. Changes made in response to OMB suggestions or
recommendations will be documented in the public record.
VIII. Reporting and Recordkeeping Requirements
The information collection requirements contained in this rule have
been submitted for approval to the Office of Management and Budget
(OMB) under the provisions of the Paperwork Reduction Act, 44 U.S.C.
3501 et seq. Public recordkeeping burden is estimated to average 115
hours per response. It is not anticipated that the revisions being
promulgated today will have any impact on the recordkeeping burden.
These requirements are not effective until OMB approves them and a
technical amendment to that effect is published in the Federal
Register.
Send comments regarding the burden estimate, including suggestions
for reducing this burden to Chief, Information Policy Branch, EPA, 401
M St., SW. (2136), Washington, DC 20460; and to the Office of
Information and Regulatory Affairs, Office of Management and Budget,
Washington, DC 20503, marked ``Attention: Desk Officer for EPA.''
IX. Impact on Small Entities
Under the Regulatory Flexibility Act, 5 U.S.C. 601 et seq., EPA is
required to determine whether a regulation will have a significant
adverse impact on a substantial number of small entities. Pursuant to
section 605(b) of the Regulatory Flexibility Act, 5 U.S.C. 605(b), the
Administrator certifies that this rule will not have a significant
economic impact on a substantial number of small entities. The new
vehicle standards will affect only manufacturers of motor vehicles and
motor vehicle engines, a group which does not contain a substantial
number of small entities. The aftermarket conversion portions of
today's regulations will not significantly impact the small businesses
in the aftermarket conversion industry because the provisions are
voluntary, and the cost of voluntary compliance with these requirements
will be small when spread over the projected volumes of conversions
expected to be sold in the near future.
X. Judicial Review
Under section 307(b)(1) of the Clean Air Act, EPA hereby finds that
these regulations are of national applicability. Accordingly, judicial
review of this action is available only by filing a petition for review
in the United States Court of Appeals for the District of Columbia
Circuit by September 21, 1994. Under section 307(b)(2) of the Act, the
requirements which are the subject of today's notice may not be
challenged later in judicial proceedings brought by EPA to enforce
these requirements.
List of Subjects
40 CFR Part 80
Environmental protection, Administrative practice and procedures,
Air pollution control, Motor vehicle pollution.
40 CFR Part 85
Imports, Labeling, Motor vehicle pollution, Reporting and
recordkeeping requirements, Research, Warranties.
40 CFR Part 86
Administrative practice and procedures, Air pollution control,
Incorporation by reference, Motor vehicles, Labeling, Motor vehicle
pollution, Reporting and recordkeeping requirements.
40 CFR Part 88
Administrative practice and procedures, Air pollution control,
Motor vehicle pollution, Reporting and recordkeeping requirements.
40 CFR Part 600
Administrative practice and procedures, Fuel economy, Incorporation
by reference, Motor vehicles, Reporting and recordkeeping requirements.
Dated: May 27, 1994.
Carol M. Browner,
Administrator.
For the reasons set forth in the preamble, parts 80, 85, 86, 88 and
600 of chapter I of title 40 of the Code of Federal Regulations are
amended, as set forth below:
PART 80--[AMENDED]
1. The authority citation for part 80 continues to read as follows:
Authority: Secs. 144, 211, and 301(a) of the Clean Air Act as
amended (42 U.S.C. 7414, 7545, and 7601(a)).
2. Section 80.2 of subpart A is amended by revising paragraphs (j)
and (o), and adding new paragraphs (oo), (tt) and (uu), to read as
follows:
Sec. 80.2 Definitions.
* * * * *
(j) Retail outlet means any establishment at which gasoline, diesel
fuel, methanol, natural gas or liquefied petroleum gas is sold or
offered for sale for use in motor vehicles.
* * * * *
(o) Wholesale purchaser-consumer means any organization that is an
ultimate consumer of gasoline, diesel fuel, methanol, natural gas or
liquefied petroleum gas and which purchases or obtains gasoline, diesel
fuel, natural gas or liquefied petroleum gas from a supplier for use in
motor vehicles and, in the case of gasoline, diesel fuel, methanol or
liquefied petroleum gas, receives delivery of that product into a
storage tank of at least 550-gallon capacity substantially under the
control of that organization.
* * * * *
(oo) Liquefied petroleum gas means a liquid hydrocarbon fuel that
is stored under pressure and is composed primarily of species that are
gases at atmospheric conditions (temperature = 25 deg.C and pressure =
1 atm), excluding natural gas.
* * * * *
(tt) Natural gas means a fuel whose primary constituent is methane.
(uu) Methanol means any fuel sold for use in motor vehicles and
commonly known or commercially sold as methanol or MXX, where XX is the
percent methanol (CH3OH) by volume.
3. Section 80.22 of subpart B is amended by revising the title to
read as follows:
Sec. 80.22 Controls applicable to gasoline and methanol retailers and
wholesale purchaser consumers.
* * * * *
4. A new Sec. 80.32 is added to subpart B, to read as follows:
Sec. 80.32 Controls applicable to liquefied petroleum gas retailers
and wholesale purchaser-consumers.
After January 1, 1998 every retailer and wholesale purchaser-
consumer handling over 13,660 gallons of liquefied petroleum gas per
month shall equip each pump from which liquefied petroleum gas is
introduced into motor vehicles with a nozzle that has no greater than
2.0 cm3 dead space from which liquefied petroleum gas will be
released upon nozzle disconnect from the vehicle, as measured from the
nozzle face which seals against the vehicle receptacle ``O'' ring, and
as determined by calculation of the geometric shape of the nozzle.
After January 1, 2000 this requirement applies to every liquefied
petroleum gas retailer and wholesale purchaser- consumer. Any
dispensing pump shown to be dedicated to heavy-duty vehicles is exempt
from this requirement.
5. A new Sec. 80.33 is added to Subpart B, to read as follows:
Sec. 80.33 Controls applicable to natural gas retailers and wholesale
purchaser-consumers.
(a) After January 1, 1998 every retailer and wholesale purchaser-
consumer handling over 1,215,000 standard cubic feet of natural gas per
month shall equip each pump from which natural gas is introduced into
natural gas motor vehicles with a nozzle and hose configuration which
vents no more than 1.2 grams of natural gas to the atmosphere per
refueling of a vehicle complying with Sec. 86.098-8(d)(1)(iv) of this
chapter, as determined by calculation of the geometric shape of the
nozzle and hose. After January 1, 2000 this requirement applies to
every natural gas retailer and wholesale purchaser-consumer. Any
dispensing pump shown to be dedicated to heavy-duty vehicles is exempt
from this requirement.
(b) The provisions of paragraph (a) of this section can be waived
for refueling stations which were in operation on or before January 1,
1998 provided the station operator can demonstrate, to the satisfaction
of the Administrator, that compliance with paragraph (a) of this
section would require additional compression equipment or other
modifications with costs similar to or greater than the cost of
additional compression equipment.
PART 85--[AMENDED]
6. The authority citation for part 85 continues to read as follows:
Authority: 42 U.S.C. 7521, 7522, 7524, 7525, 7541, 7542, 7543,
7547, and 7601(a), unless otherwise noted.
7. A new subpart F is added to part 85 to read as follows:
Subpart F--Exemption of Aftermarket Conversions From Tampering
Prohibition
Sec.
85.501 General applicability.
85.502 Definitions.
85.503 Conditions of exemption.
85.504 Applicable standards.
85.505 Labeling.
Subpart F--Exemption of Aftermarket Conversions From Tampering
Prohibition
Sec. 85.501 General applicability.
Sections 85.501 through 85.505 are applicable to aftermarket
conversion systems for which an enforcement exemption is sought from
the tampering prohibitions contained in section 203 of the Act.
Sec. 85.502 Definitions.
(a) The Act means the Clean Air Act as amended (42 U.S.C. 7501 et
seq.).
(b) Administrator means the Administrator of the Environmental
Protection Agency or his or her authorized representative.
(c) Aftermarket conversion system means any combination of
hardware, including but not limited to fuel storage and fuel metering
hardware, which is installed on a light-duty vehicle, light-duty truck,
heavy-duty vehicle, or heavy-duty engine with the effect of allowing
the vehicle or engine to operate on a fuel other than the fuel which
the vehicle or engine was originally certified to use. Components which
do not affect the emissions performance of the converted vehicle or
engine, as determined by the Administrator, are not included for the
purposes of this subpart.
(d) Aftermarket conversion installer means any company or
individual which installs an aftermarket conversion system on a light-
duty vehicle, light-duty truck, heavy-duty vehicle, or heavy-duty
engine with the effect of allowing the vehicle or engine to operate on
a fuel other than the fuel which the vehicle or engine was originally
certified to use.
(e) Aftermarket conversion certifier means any company or
individual which assembles the various aftermarket conversion hardware
components into a particular combination or configuration and certifies
that combination or configuration according to the provisions of this
subpart.
(f) Model Year means the manufacturer's annual production period
(as determined by the Administrator) which includes January 1 of such
calendar year: Provided, That if the manufacturer has no annual
production period, the term model year shall mean the calendar year.
Sec. 85.503 Conditions of exemption.
(a) As a condition of receiving an enforcement exemption from the
tampering prohibitions contained in section 203 of the Act, an
aftermarket conversion certifier must certify the aftermarket
conversion system, using the applicable procedures in part 86 of this
chapter, and meeting the applicable standards and requirements in
Secs. 85.504 and 85.505, and accept liability for in- use performance
of the aftermarket conversion system as outlined in this part.
(b) As a condition of receiving an enforcement exemption from the
tampering prohibitions contained in section 203 of the Act, an
aftermarket conversion installer must:
(1) Install a conversion which has been certified as a new vehicle
or engine, using the applicable procedures in part 86 of this chapter,
and meeting the applicable standards and requirements in Secs. 85.504
and 85.505; and
(2) Accept liability for in-use performance of the aftermarket
conversion system as outlined in this part.
Sec. 85.504 Applicable standards.
(a) The emission standards applicable to conversions of 1993 and
later model year vehicles and engines are:
(1) All of the requirements that would apply if the conversion were
being certified as if it were a new vehicle or engine.
(2) If a vehicle or engine to be converted was originally certified
to a NOX or particulate family emission limit other than the
applicable new vehicle NOX or particulate standard, the family
emission limit is the applicable standard.
(b) The emission standards applicable to conversions of 1992 and
earlier model year vehicles and engines are:
(1) Exhaust hydrocarbons (as applicable by fuel type). The Tier 0
hydrocarbon standards, as applicable by vehicle class, contained in
Secs. 86.094-8 and 86.094-9 of this chapter, and the hydrocarbon
standards, as applicable by engine class, contained in Secs. 86.094-10
and 86.094-11 of this chapter;
(2) CO, NOX and particulate. The applicable CO, NOX and
particulate standards or NOX and particulate family emission
limits the vehicle or engine was originally certified as meeting;
(3) Evaporative hydrocarbons. Any evaporative requirements
applicable to the original vehicle or engine will remain applicable to
the conversion if the converted vehicle or engine retains the ability
to operate on the fuel which it was designed and certified to use.
Sec. 85.505 Labeling.
(a) The aftermarket conversion certifier shall provide with each
aftermarket conversion system a supplemental emission control
information label, which shall be affixed by the aftermarket conversion
installer in a permanent manner to each converted vehicle, in a
location adjacent to the original emission control information label
required in Sec. 86.092-35 of this chapter. If the supplemental label
cannot be placed adjacent to the original label, it shall be placed in
a location where it will be seen by a person viewing the original
label.
(b) The supplemental label shall be affixed in such a manner that
it cannot be removed without destroying or defacing the label. The
label shall not be affixed to any equipment which is easily detached
from the vehicle.
(c) The supplemental label shall clearly state that the vehicle has
been equipped with an aftermarket conversion system designed to allow
it to operate on a fuel other than the fuel it was originally
manufactured to operate on, and shall identify the fuel(s) which the
vehicle is designed to use.
(d) The supplemental label shall show the vehicle model year; the
aftermarket conversion certifier's name, address and telephone number;
the installer's name, address, and telephone number; the date on which
the aftermarket conversion system was installed; the mileage of the
vehicle at the time of the conversion; and shall state that the
converted vehicle complies with federal emission requirements.
(e) The supplemental label shall list any original parts that were
removed during installation of the aftermarket conversion system, as
well as any changes in tune-up specifications required for the
aftermarket conversion system.
PART 86--[AMENDED]
8. The authority citation for Part 86 continues to read as follows:
Authority: Secs. 202, 203, 205, 206, 207, 208, 215, 216, 217 and
301(a) of the Clean Air Act as amended; 42 U.S.C. 7521, 7522, 7524,
7525, 7541, 7542, 7549, 7550, 7552 and 7601(a)).
9. Section 86.1 is amended by revising the table in paragraph
(b)(1) and adding a new paragraph (b)(3), to read as follows:
Sec. 86.1 Reference materials.
* * * * *
(b) * * *
(1) * * *
------------------------------------------------------------------------
Document number and name 40 CFR part 86 reference
------------------------------------------------------------------------
ASTM E29-67 (Reapproved 1980), 86.094-26; 86.094-28; 86.1105-87
Standard Recommended Practice for
Indicating Which Places of Figures
Are To Be Considered Significant
in Specified Limiting Values.
ASTM E29-90, Standard Practice for 86.609-84; 86.609-96; 86.1009-84;
Using Significant Digits in Test 86.1009-96; 86.1442
Data To Determine Conformance with
Specifications.
ASTM D2163-91, Standard Test Method 86.113-91; 86.113-94; 86.1213-94;
for Analysis of Liquefied 86.1313-90
Petroleum (LP) Gases and Propane
Concentrates by Gas Chromatography.
ASTM D1945-91, Standard Test Method 86.113-91; 86.113-94; 86.513-90;
for Analysis of Natural Gas By Gas 86.1213-94; 86.1313-90
Chromatography.
------------------------------------------------------------------------
* * * * *
(3) ANSI material. The following table sets forth material from the
American National Standards Institute that has been incorporated by
reference. The first column lists the number and name of the material.
The second column lists the section(s) of this part, other than
Sec. 86.1, in which the matter is referenced. The second column is
presented for information only and may not be all inclusive. Copies of
these materials may be obtained from the American National Standards
Institute, 11 West 42nd Street, 13th Floor, New York, NY 10036.
------------------------------------------------------------------------
Document number and name 40 CFR part 86 reference
------------------------------------------------------------------------
ANSI/AGA NGV1-1994, Standard for 86.001-9; 86.004-9; 86.098-8;
Compressed Natural Gas Vehicle 86.099-8; 86.099-9
(NGV) Fueling Connection Devices.
------------------------------------------------------------------------
10. The title of subpart A of part 86 is revised to read as
follows:
Subpart A--General Provisions for Emission Regulations for 1977 and
later Model Year New Light-Duty Vehicles, Light-Duty Trucks and
Heavy-Duty Engines, and for 1985 and Later Model Year New Gasoline
Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas-Fueled and
Methanol-Fueled Heavy-Duty Vehicles
11. Section 86.001-9 of subpart A is amended by adding new
paragraphs (d)(1)(iii) and (d)(1)(iv), to read as follows:
Sec. 86.001-9 Emission standards for 2001 and later model year light-
duty trucks.
* * * * *
(d) * * *
(1) * * *
(iii) Hydrocarbons (for liquefied petroleum gas-fueled vehicles).
0.15 gram per gallon (0.04 gram per liter) of fuel dispensed.
(iv) Refueling receptacle (for natural gas-fueled vehicles).
Refueling receptacles on natural gas-fueled vehicles shall comply with
the receptacle provisions of the ANSI/AGA NGV1-1994 standard (as
incorporated by reference in Sec. 86.1).
* * * * *
12. Section 86.001-28 of subpart A is amended by adding a new
paragraph (h) to read as follows:
Sec. 86.001-28 Compliance with emission standards.
* * * * *
(h) Fixed liquid level gauge waiver. Liquefied petroleum gas-fueled
vehicles which contain fixed liquid level gauges or other gauges or
valves which can be opened to release fuel or fuel vapor during
refueling, and which are being tested for refueling emissions, are not
required to be tested with such gauges or valves open, as outlined in
Sec. 86.157-98(d)(2), provided the manufacturer can demonstrate, to the
satisfaction of the Administrator, that such gauges or valves would not
be opened during refueling in-use due to inaccessibility or other
design features that would prevent or make it very unlikely that such
gauges or valves could be opened.
13. Section 86.004-9 of subpart A is amended by adding new
paragraphs (d)(1)(iii) and (d)(1)(iv), to read as follows:
Sec. 86.004-9 Emission standards for 2004 and later model year light-
duty trucks.
* * * * *
(d) * * *
(1) * * *
(iii) Hydrocarbons (for liquefied petroleum gas-fueled vehicles).
0.15 gram per gallon (0.04 gram per liter) of fuel dispensed.
(iv) Refueling receptacle (for natural gas-fueled vehicles).
Refueling receptacles on natural gas-fueled vehicles shall comply with
the receptacle provisions of the ANSI/AGA NGV1-1994 standard (as
incorporated by reference in Sec. 86.1).
* * * * *
14a. Section 86.004-28 of subpart A is amended by adding a new
paragraph (h) to read as follows:
Sec. 86.004-28 Compliance with emission standards.
* * * * *
(h) Fixed liquid level gauge waiver. Liquefied petroleum gas-fueled
vehicles which contain fixed liquid level gauges or other gauges or
valves which can be opened to release fuel or fuel vapor during
refueling, and which are being tested for refueling emissions, are not
required to be tested with such gauges or valves open, as outlined in
Sec. 86.157-98(d)(2), provided the manufacturer can demonstrate, to the
satisfaction of the Administrator, that such gauges or valves would not
be opened during refueling in-use due to inaccessibility or other
design features that would prevent or make it very unlikely that such
gauges or valves could be opened.
14b. Section 86.084-4 is amended by redesignating paragraph (b) as
paragraph (c) and adding a new paragraph (b) to read as follows:
Sec. 86.084-4 Section numbering; construction.
* * * * *
(b) A section reference without a model year suffix refers to the
section applicable for the appropriate model year.
* * * * *
15. Section 86.091-10 of subpart A is amended by revising
paragraphs (a)(1) introductory text, (a)(1)(i) introductory text,
(a)(1)(i)(B)(2), (a)(1)(ii) introductory text, (a)(1)(ii)(B)(2) and
(a)(3), and by adding paragraphs (a)(1)(i)(C)(3), (a)(1)(ii)(C)(3),
(a)(1)(v), and (a)(1)(vi), to read as follows:
Sec. 86.091-10 Emission standards for 1991 and later model year Otto-
cycle heavy-duty engines and vehicles.
(a)(1) Exhaust emissions from new 1991 and later model year Otto-
cycle heavy-duty engines shall not exceed (compliance with these
standards is optional through the 1996 model year natural gas- and
liquefied petroleum gas-fueled heavy-duty engines):
(i) For Otto-cycle heavy-duty engines fueled with either gasoline
or liquefied petroleum gas, and intended for use in all vehicles except
as provided in paragraph (a)(3) of this paragraph.
* * * * *
(B) * * *
(2) For Otto-cycle heavy-duty engines fueled with either gasoline
or liquefied petroleum gas and utilizing aftertreatment technology.
0.50 percent of exhaust gas flow at curb idle.
(C) * * *
(3) A manufacturer may elect to include any or all of its liquefied
petroleum gas-fueled Otto-cycle heavy-duty engine families in any or
all of the NOX averaging, trading, or banking programs for heavy-
duty engines, within the restrictions described in Sec. 86.091-15. If
the manufacturer elects to include engine families in any of these
programs, the NOX FELs may not exceed 6.0 grams per brake
horsepower-hour (2.2 grams per megajoule). This ceiling value applies
whether credits for the family are derived from averaging, trading or
banking programs.
(ii) For Otto-cycle heavy-duty engines fueled with either gasoline
or liquefied petroleum gas, and intended for use only in vehicles with
a Gross Vehicle Weight Rating of greater than 14,000 lbs.
* * * * *
(B) * * *
(2) For Otto-cycle heavy-duty engines fueled with either gasoline
or liquefied petroleum gas and utilizing aftertreatment technology.
0.50 percent of exhaust gas flow at curb idle.
(C) * * *
(3) A manufacturer may elect to include any or all of its liquefied
petroleum gas-fueled Otto-cycle heavy-duty engine families in any or
all of the NOX averaging, trading or banking programs for heavy-
duty engines, within the restrictions described in Sec. 86.091-15. If
the manufacturer elects to include engine families in any of these
programs, the NOX FELs may not exceed 6.0 grams per brake
horsepower-hour (2.2 grams per megajoule). This ceiling value applies
whether credits for the family are derived from averaging, trading or
banking programs.
* * * * *
(v) For natural gas-fueled Otto-cycle heavy-duty engines intended
for use in all vehicles except as provided in paragraph (a)(3) of this
section.
(A) Nonmethane hydrocarbons. 0.9 gram per brake horsepower-hour
(0.33 gram per megajoule), as measured under transient operating
conditions.
(B) Carbon monoxide. (1) 14.4 grams per brake horsepower-hour (5.36
grams per megajoule), as measured under transient operating conditions.
(2) For natural gas-fueled Otto-cycle heavy-duty engines utilizing
aftertreatment technology. 0.50 percent of exhaust flow at curb idle.
(C) Oxides of nitrogen. (1) 5.0 grams per brake horsepower-hour
(1.9 grams per megajoule), as measured under transient operating
conditions.
(2) A manufacturer may elect to include any or all of its natural
gas-fueled Otto-cycle heavy-duty engine families in any or all of the
NOX averaging, trading or banking programs for heavy-duty engines,
within the restrictions described in Sec. 86.091-15. If the
manufacturer elects to include engine families in any of these
programs, the NOX FELs may not exceed 6.0 grams per brake
horsepower-hour (2.2 grams per megajoule). This ceiling value applies
whether credits for the family are derived from averaging, trading or
banking programs.
(vi) For natural gas-fueled Otto-cycle engines intended for use
only in vehicles with a Gross Vehicle Weight Rating of greater than
14,000 lbs.
(A) Nonmethane hydrocarbons. 1.7 grams per brake horsepower-hour
(0.63 gram per megajoule), as measured under transient operating
conditions.
(B) Carbon monoxide. (1) 37.1 grams per brake horsepower-hour (13.8
grams per megajoule), as measured under transient operating conditions.
(2) For natural gas-fueled Otto-cycle heavy-duty engines utilizing
aftertreatment technology. 0.50 percent of exhaust gas flow at curb
idle.
(C) Oxides of nitrogen. (1) 5.0 grams per brake horsepower-hour
(1.9 grams per megajoule), as measured under transient operating
conditions.
(2) A manufacturer may elect to include any or all of its natural
gas-fueled Otto-cycle heavy-duty engine families in any or all of the
NOX averaging, trading or banking programs for heavy-duty engines,
within the restrictions described in Sec. 86.091-15. If the
manufacturer elects to include engine families in any of these
programs, the NOX FELs may not exceed 6.0 grams per brake
horsepower-hour (2.2 grams per megajoule). This ceiling value applies
whether credits for the family are derived from averaging, trading or
banking programs.
* * * * *
(3)(i) A manufacturer may certify one or more Otto-cycle heavy-duty
engine configurations intended for use in all vehicles to the emission
standards set forth in paragraphs (a)(1)(ii), (a)(1)(iv) or (a)(1)(vi)
of this section: Provided, that the total model year sales of such
configuration(s), segregated by fuel type, being certified to the
emission standards in paragraph (a)(1)(ii) of this section represent no
more than five percent of total model year sales of each fuel type
Otto-cycle heavy-duty engine intended for use in vehicles with a Gross
Vehicle Weight Rating of up to 14,000 pounds by the manufacturer.
(ii) The configurations certified to the emission standards of
paragraphs (a)(1) (ii), (iv) and (vi) of this section under the
provisions of paragraph (a)(3)(i) of this section shall still be
required to meet the evaporative emission standards set forth in
paragraphs (b)(1)(i), (b)(2)(i) and (b)(3)(i) of this section.
* * * * *
16. Section 86.091-28 of subpart A is amended by revising
paragraphs (a)(4)(i) introductory text, (a)(4)(i)(C), (a)(4)(ii)(B),
(a)(7)(i), (b)(4)(ii), (b)(4)(iii), (b)(6)(i), (c)(4)(ii),
(c)(4)(iii)(A)(1), (c)(4)(iii)(A)(2), (c)(4)(iii)(B)(1),
(c)(4)(iii)(B)(2) and (d)(1) to read as follows:
Sec. 86.091-28 Compliance with emission standards.
(a) * * *
(4) * * *
(i) Separate emission deterioration factors shall be determined
from the exhaust emission results of the durability-data vehicle(s) for
each engine-system combination. A separate factor shall be established,
as required for compliance with applicable emission standards for
exhaust HC, exhaust OMHCE, exhaust NMHC, exhaust CO, exhaust NOX
and exhaust particulate for each engine-system combination. A separate
evaporative emission deterioration factor, as required for compliance
with applicable emission standards, shall be determined for each
evaporative emission family-evaporative emission control system
combination from the testing conducted by the manufacturer.
* * * * *
(C)(1) An evaporative emissions deterioration factor shall be
determined from the testing conducted as described in Sec. 86.090-
21(b)(4)(i), for each evaporative emission family- evaporative emission
control system combination to indicate the evaporative emission level
at 50,000 miles relative to the evaporative emission level at 4,000
miles as follows:
Factor = Evaporative emission level at 50,000 miles minus the
evaporative emission level at 4,000 miles.
(2) The factor in paragraph (a)(4)(i)(C)(1) of this section shall
be established to a minimum of two places to the right of the decimal.
(ii) * * *
(B) The official evaporative emission test results for each
evaporative emission-data vehicle at the selected test point shall be
adjusted by addition of the appropriate deterioration factor: Provided,
that if a deterioration factor as computed in paragraph (a)(4)(i)(C) of
this section is less than zero, that deterioration factor shall be zero
for the purposes of this paragraph.
* * * * *
(7) * * *
(i) Separate deterioration factors shall be determined from the
exhaust emission results of the durability-data vehicles for each
engine family group. A separate factor as necessary to establish
compliance with applicable emission standards shall be established for
exhaust HC, exhaust OMHCE, exhaust NMHC, exhaust CO and exhaust
NOX for each engine family group. The evaporative emission
deterioration factor for each evaporative family will be determined and
applied in accordance with paragraph (a)(4) of this section.
* * * * *
(b) * * *
(4) * * *
(ii) Separate exhaust emission deterioration factors, determined
from tests of vehicles, engines, subsystems or components conducted by
the manufacturer, shall be supplied for each engine-system combination.
Separate factors shall be established as required for compliance with
applicable emission standards for transient HC, OMHCE, NMHC, CO, and
NOX, idle CO and exhaust particulate.
(iii) For tr
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