Direct Final Rule Amending the Test Procedures for Heavy-Duty Engines, and Light-Duty Vehicles and Trucks and the Amending of Emission Standard Provisions for Gaseous Fueled Vehicles and Engines

Federal RegisterSep 5, 1997

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 9 and 86

[FRL-5881-3]

Direct Final Rule Amending the Test Procedures for Heavy-Duty

Engines, and Light-Duty Vehicles and Trucks and the Amending of

Emission Standard Provisions for Gaseous Fueled Vehicles and Engines

AGENCY: Environmental Protection Agency (EPA).

ACTION: Direct final rule.

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SUMMARY: This action promulgates amendments to several sections of the

heavy-duty engine test procedure regulations in 40 CFR part 86. These

changes are needed in order to accommodate the use of new testing

equipment, to provide greater flexibility in the type of testing

equipment used and to ensure uniform calibration and use of the testing

equipment. The amendments will ensure the continued validity of testing

results and ensure that heavy-duty engines are being exercised

appropriately over the test procedures. This action also makes limited

changes to the light-duty vehicle and truck test procedure regulations

and the gaseous fuel emission standards in 40 CFR part 86. Because

changes are limited to technical issues, all of which have been

coordinated with industry, EPA expects no adverse comments.

DATES: This rule will be effective January 5, 1998 unless notice is

received by October 6, 1997 that adverse or critical comments will be

submitted on a specific element of this rule. If such comments are

received, then EPA will publish a subsequent document in the Federal

comments were made.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of January 5, 1998.

ADDRESSES: Interested parties may submit written comments in response

to this notice (in duplicate, if possible) to Public Docket A-96-07 at

Air Docket Section, U.S. Environmental Protection Agency, First Floor,

Waterside Mall, Room M-1500, 401 M Street SW, Washington DC 20460. A

copy of the comments should also be sent to the contact person listed

below.

FOR FURTHER INFORMATION CONTACT: Mr. Jaime Pagan, U.S. Environmental

Protection Agency, Engine Programs and Compliance Division, 2565

Plymouth Rd., Ann Arbor, MI 48105. Telephone: (313) 668-4574, fax:

(313) 741-7816.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction

II. List of Changes to Test Procedures

III. Environmental and Economic Impacts

IV. Public Participation

V. Statutory Authority

VI. Administrative Designation and Regulatory Analysis

VII. Compliance with Regulatory Flexibility Act

VIII. Unfunded Mandates

IX. Paperwork Reduction Act

X. Submission to Congress and the General Accounting Office

XI. Copies of Rulemaking Documents

I. Introduction

EPA's Smoke Exhaust and Gaseous and Particulate Exhaust Test

Procedures for certification and Selective Enforcement Audit (SEA)

provide a consistent method for testing and obtaining emissions data

from heavy-duty engines. This action promulgates amendments to the test

procedures in order to accommodate the use of new testing equipment and

clarify certain issues that have been identified since these procedures

were first published.

Over the last few years, EPA and the Engine Manufacturers

Association (EMA) have worked together to identify the issues that

needed revision or clarification. During these interactions,

suggestions were made involving specific changes to the test

procedures. In general, the technical amendments included in this

action fall into two categories. First, many of the amendments are

simply clarifications that will help remove any potential ambiguities

or inconsistencies. Second, another group of amendments take into

account testing equipment and/or engine technology that was not as

widely used when the rule was first written.

The changes to the Smoke Exhaust Test Procedure include

clarifications regarding the operation of the dynamometer,

accommodation of additional test equipment and more details on meter

light sources to be used. The test procedures for SEA contain a new

requirement that asks manufacturers to decide, before the initial cold

cycle, whether they will measure background particulate matter (PM) or

not. Promulgated amendments to the Gaseous and Particulate Test

Procedures cover the calibration requirements of gas analyzers, the use

of accessory loads, conditions for use of charge air cooling devices

and the permitted point deletions from regression analysis.

Lastly, three minor changes to the Gaseous Fueled Vehicle Rule,

established in a September 21, 1994 notice (59 FR 48472), are made. The

regulatory text of that rule contained several minor errors and areas

where the applicability of various standards to gaseous-fueled vehicles

was not clear in the regulations, although all of the applicability

issues were discussed in the preamble. The following section presents a

more detailed overview of the specific amendments that EPA is

promulgating in this action.

II. List of Changes to Test Procedures

1. Changes and clarifications regarding dynamometer control

throughout the operation cycle for smoke emission tests (Sec. 86.884-

7(a) and Sec. 86.884-13(b)(6)). These changes respond to the need to

better define the acceleration mode in the smoke test cycle. The

amendments to the regulatory language make the speed and acceleration

requirements more specific. In addition, it is clarified that during

the last 10 seconds of the lugging mode the average engine speed and

the average observed power shall be maintained within their specified

values. Furthermore, the regulations are revised to state that within

five seconds of the completion of the lugging mode, the dynamometer and

engine controls shall be returned to idle position. These

specifications are needed to ensure uniformity in how the procedures

are followed.

2. Allow the use of newer in-line smokemeters and accommodate

multistack engines to the smoke exhaust test procedure (Sec. 86.884-

8(c) and Sec. 86.884-14). In-line smokemeters, which were not available

when the original rule was written, are now taken into account in the

test procedure. The purpose of this addition is to provide engine

manufacturers the flexibility of using this type of equipment. The use

of in-line smokemeters is acceptable since it does not affect test

results. Also, specifications for the distance between the smokemeter

and the exhaust manifold, turbocharger outlet, aftertreatment device or

crossover junction (whichever is farthest downstream), are now included

in the regulations. Such distance specifications are needed to ensure a

uniform procedure and repeatable test results.

3. Clarify the specifications for the type of light sources to be

used during smoke testing (Sec. 86.884-9 (b)(2) and (c)). These

clarifications specify the color temperature range and spectral peak

for

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smokemeter light sources. It is also specified that light detectors

shall be a photocell or a photodiode. In addition, it is now specified

that the distance from the optical centerline of the smokemeter to the

exhaust pipe outlet is 10.25 inches. The new language adds

specificity by providing specific ranges for these parameters and adds

flexibility by allowing the use of more current smokemeter technology.

4. Semantic clarification for the smoke test: Curb Idle rpm versus

Idle rpm (Sec. 86.884-7(a)(4) and Sec. 86.884-10(a)(8)). The word

``Curb'' was eliminated from the term ``Curb Idle rpm'' in the smoke

test procedure. When running a smoke test on an engine with Curb Idle

Transmission Torque (CITT), it is very difficult to maintain the

desired idle speed without having to adjust the controls. The change in

the regulatory language simply allows to operate the engine at free

idle speed and does not affect test results.

5. New calculations are provided to support the use of in-line

smokemeters (Sec. 86.884-14(a)). EPA provides an equation to determine

the standard half-second percent opacity, if the opacity is being

measured using a smokemeter with a different optical path length than

the one specified in Sec. 86.884-8. This calculation will help support

the use of current in-line smokemeters.

6. Selective Enforcement Auditing Test Procedures: Require that

manufacturers decide, before the start of the cold cycle, whether they

will measure background particulate matter (PM). The test shall be

voided if the manufacturer fails to measure background PM after

initially saying it would (Sec. 86.1008-90(a), Sec. 86.1008-96(a),

Sec. 86.1008-2001(a) and Sec. 86.1111-87(a)). The CFR

(Sec. 86.1310(b)(1)(iv)(C)) states that the primary dilution air may be

sampled to determine background PM levels. Since this measurement is

not required, a valid test may be run without sampling for background

particulate. Background particulate can make a significant contribution

to the total particulate collected on the sample filter, especially at

emission levels of 0.10 g/bhp-hr and below. As a result, most

manufacturers choose to measure background particulate.

During Selective Enforcement Audit (SEA) testing, manufacturers

will occasionally have problems measuring background particulate.

Improper handling of the background filters is the usual cause of these

problems. Manufacturers typically want to weigh the sample filters

before deciding whether or not to void the test. If the engine passes

based on the sample filter weights, the manufacturer will not void the

test since including background emissions will only lower an already

passing particulate value. However, if the engine fails based solely on

the sample filter weights, the manufacturer will want to void the test

since the engine may pass if background correction is included.

Although it is certain that an engine that passes without

background correction will pass with background correction, it is

uncertain if an unmeasured background correction will lower the

particulate level of a failing engine enough to pass. An engine with

failing sample filter weights may pass when retested solely as the

result of test-to-test variability, lowering its emission level.

Therefore EPA will now require that manufacturers decide, before

the start of the cold cycle, whether they will measure background PM.

The test shall be voided if the manufacturer fails to measure

background PM after initially saying it would.

7. Clarify the procedure for sampling background particulate

(Sec. 86.1310-90(b)(1)(iv)(C)). The new language adds specificity to

the exhaust gas sampling method by stipulating that the primary

dilution air shall be sampled at the inlet to the primary dilution

tunnel, if unfiltered, or downstream of any primary dilution air

conditioning devices that are used.

8. Clarify the hydrocarbon (HC) probe location and line temperature

requirements and introduce a new approach for demonstrating the

temperature profile of heated lines (Sec. 86.1310-90(b)(3)). This

clarification will provide more uniformity to the test procedures by

requiring specific probe locations and line temperature requirements.

The revisions to the regulations require that the temperature

requirements of the hydrocarbon (HC) sample line shall be met over its

entire length and not just at the measurement points. Since the gas

temperature can not instantly be brought up to the required

temperature, the length of the sample probe is defined as the length at

which the gas temperature must meet specifications.

9. Require that all particulate matter (PM) filters (sample,

reference and background) are to be handled in pairs during all

weighing (Sec. 86.1310-90(b)(7), Sec. 86.1312-88(a) (3) & (4), and

Sec. 86.1337). This measure will help reduce error and ensure the

uniform use of all filter samples. More accurate measurements can be

obtained by weighing the filters in pairs.

10. Recommend that PM filter loading be maximized consistent with

other temperature requirements and the requirement to avoid moisture

condensation (Sec. 86.1310-90(b)(7)(iv)). The new language will ensure

that PM measurements are accurate by having a filter loading that is

consistent with temperature and moisture requirements. Furthermore, EPA

recommends that the filter pair loading be proportional to the engine's

emission level. For example, a filter pair loading of 1 mg is typically

proportional to a 0.1 g/bhp-hr PM emission level. This change

eliminates the previous 5.3 milligram filter loading requirement which

is too difficult to achieve with today's low PM emitting engines.

11. Apply the same proportional sampling requirement to the

Critical Flow Venturi (CFV-CVS) and the Positive Displacement Pump-

Constant Volume Sampler (PDP-CVS) systems (Sec. 86.1310-90(b)(6),

Sec. 86.1337-90(a)(10), Sec. 86.1337-96(a)(10)). This new language

consolidates the requirement for demonstrating, during diesel

particulate testing, sample flow proportionality for both the single-

dilution and double-dilution methods. Prior to the change, PDP-CVS

systems were only required to demonstrate that flow through the

particulate transfer tube was constant, plus or minus five percent. The

CFV-CVS was required to demonstrate that the ratio of main tunnel flow

to particulate sample flow did not change by more than plus or minus

five percent. The requirements for the two CVS systems are the same

assuming that flow through the PDP-CVS does not vary. Since this

assumption is not always true, the proportionality requirements for the

PDP-CVS and the CFV-CVS are not equivalent. To correct this,

laboratories with a PDP-CVS sampling system are required to meet the

same requirements as the CFV-CVS system, which is to demonstrate that

the ratio of main tunnel flow to particulate sample flow did not change

by more than plus or minus five percent.

12. Clarify the ambient condition requirements for the filter

weighing room (Sec. 86.1312-88(a) (1) & (2)). This new language helps

resolve some inconsistencies between the light-and heavy-duty test

procedures. The new humidity requirement states that the room shall be

maintained at a dew point temperature of 282.5K 3K

(9.4 deg.C 3 deg.C) and a relative humidity of 45%

8%. The ambient temperature requirement in the room is

revised to 295K 3K (22 deg.C 3 deg.C) during

all filter conditioning and weighing.

13. Allow a change in weight on the reference filters, between

weighings, by an absolute number rather than a percentage of the

nominal filter loading

[[Page 47116]]

(Sec. 86.1312-88(a)(4)). Sample and background filter pairs that are in

the process of stabilization shall be discarded if the average weight

of the reference filter pair changes by more than 40 micrograms. This

change simplifies the old requirement where a 5 percent

change from the nominal filter loading was allowed. EPA considers that

it is better practice to have a filter weight variation requirement

that does not vary with the nominal filter loading since a specific

loading is not required, but is only recommended.

14. Change in the conditioning room timing requirement

(Sec. 86.1312-88(a)(5)). If any of the environmental conditions in the

conditioning room, as specified in the test procedures, are not met,

then it is required that the filters remain in the conditioning room

for at least one hour after correct conditions are met prior to

weighing. This amendment eliminates a previously unnecessary timing

requirement and adds a new option for manufacturers that gives them

greater flexibility in following the test procedures.

15. Specify a new ASTM procedure for measuring aromatic composition

in diesel fuel (Sec. 86.1313-91, Sec. 86.1313-94, Sec. 86.1313-98). The

amendment allows, for heavy-duty diesel engines of model years 1987

thru 1997, the use of ASTM procedure D5186-91 for measuring aromatic

composition. For model years 1998 and later, ASTM D5186-91 will be the

required procedure for measuring aromatic composition.

16. For diesel fuel testing only, change the requirement of

calibrating the CO analyzer to bi-monthly or immediately after

maintenance (Sec. 86.1316-90). This amendment loosens the monthly

calibration requirement due to the typically low levels of CO, relative

to the standard, produced by heavy-duty diesel engines.

17. Change a requirement to generate new calibration curves each

month (Sec. 86.1316-90, Sec. 86.1316-94). This amendment adds

flexibility to the test procedure by allowing the manufacturer not to

generate a new calibration curve for an analyzer if they have

demonstrated that it has not significantly varied from its last

calibration. This change does not affect the accuracy of the analyzers,

but simplifies the calibration process.

18. Clarify the method for issuing speed and torque command

setpoints throughout the test cycle (Sec. 86.1327-90(b), Sec. 86.1327-

94(b), Sec. 86.1327-96(b)). The frequency for issuing the command

setpoints for engine torque and speed were not specified in the

original rule. It is now clarified that the torque and speed command

setpoints shall be issued at 5 Hz or greater.

19. Clarify the exhaust system and insulation requirements for

diesel engines equipped with catalysts (Sec. 86.1327-90(f),

Sec. 86.1327-94(f), Sec. 86.1327-96(f)). These amendments respond to

the need to account for exhaust aftertreatment technology, which is

seeing a wider use in current heavy-duty engines. The language being

added to the regulations specifies that the exhaust pipe diameter shall

be the same as that found in-use. In addition, it is specified that for

gasoline and diesel engines, the catalyst container may be removed

during all test sequences prior to the practice cycle, and replaced

with an equivalent container having an inactive catalyst support. The

reason for allowing such option to manufacturers is that the catalyst

may be consumed by the high exhaust temperatures experienced during

testing. Finally, it is also specified that the distance from the

exhaust manifold flange or turbocharger outlet to any exhaust

aftertreatment device shall be the same as the vehicle configuration or

within the distance specifications that the engine manufacturers

provide for the installation of such devices.

20. Clarify that loading from accessories is considered parasitic

in nature and that their work shall not be included in the emission

calculations (Sec. 86.1327-98, Sec. 86.1341-98(b)(3)). The accessory

loading is considered parasitic because it is not providing any

``useful work''. ``Useful work'' is the work that the application (that

uses the engine in question) does when commanded by an operator. The

amendment clarifies that accessories such as oil coolers, alternators,

air compressors, etc., if used, shall be applied to all engine testing

operations. Their work, however, shall not be included in the

integrated work used in emission calculations. This clarification adds

consistency between emission test results from different engines, which

do not necessarily operate with the same accessories.

21. Require the following of SAE Recommended Practice J1937 for

simulating the use of a charge air cooling device while running the FTP

in a dynamometer test cell (Sec. 86.1330-84(b)(5), Sec. 86.1330-

90(b)(5)). The following of this procedure will help ensure the uniform

use of such devices, which were not of common use when the original

rule was written.

22. Define new intake and exhaust restriction setting requirements

for diesel fueled heavy-duty engines (Sec. 86.1330-84(f) and

Sec. 86.1330-90(f)). This new language replaces earlier language that

required the manufacturers to demonstrate some average restrictions

that their engines would typically experience in-use. The old

requirements were very difficult to meet. The new requirement for the

air inlet specifies a restriction setting which is midway between a

clean filter and the maximum restriction specified by the manufacturer.

In addition, the new requirement for exhaust restriction is 80 percent

of the manufacturer's recommended maximum specified exhaust

restriction. Furthermore, EPA still holds the manufacturer accountable

for the entire range of restrictions that the engine might experience

in-use.

23. Correct the temperature requirement of the CVS dilution air

(Sec. 86.1330-84(b), Sec. 86.1330-90(b)). The language added makes the

dilution air temperature requirement consistent with Sec. 86.1310-90,

which is 68 deg.F (20 deg.C) for Otto cycle engines and between

68 deg.F and 86 deg.F (20 deg.C and 30 deg.C) for diesel cycle engines.

24. Change the required torque command set-points in the FTP that

utilize the provisions related to Curb Idle Torque (CITT)

(Sec. 86.1333-90). The manufacturer is allowed to modify all torque

command set-points to CITT when the speed command set-point is equal to

or less than zero percent and the ``initial'' torque command set-point

is less than CITT. This language corrects a problem where, in certain

cases, a low torque command resulted in a real torque command less than

CITT, which is an operating condition that these engines do not

typically encounter in-use.

25. Clarify the idle torque requirements for cycle validation

(Sec. 86.1333-90). The existing language for idle torque requirements

is clarified to make it more understandable.

26. Apply a single set of requirements to both forced and natural

cool downs which precede the cold start exhaust emissions test

(Sec. 86.1334-84 and Sec. 86.1335-90). This change defines a cold

engine as one with oil and water temperatures between 68 and 86 deg.F.

This is a change from the existing natural cool down requirements which

call for only oil temperature to be stabilized between 68 and 86

deg.F. The temperature requirements for forced cool down are now the

same as for natural cool down, thus providing one definition for a cold

engine regardless of the cool down procedure.

27. Correct an oversight regarding the first FTP idle definition

(Sec. 86.1337-90 and Sec. 86.1337-96). This amendment adds language to

Sec. 86.1337-90 and Sec. 86.1337-96 that was inadvertently lost

[[Page 47117]]

from Sec. 86.1337-88. It also corrects a paragraph reference in the

same sections and eliminates specifications for particulate testing

without the use of flow compensation because these specifications are

no longer needed since the same particulate sampling requirements now

apply for systems with and without flow compensation.

28. Clarify the procedure for calibrating gaseous emission

analyzers (Sec. 86.1321-90, Sec. 86.1321-94, Sec. 86.1322-84,

Sec. 86.1323-84, Sec. 86.1324-84 and Sec. 86.1325-94, Sec. 86.1338-84).

The data points requirements for calibrating analyzers below 15 percent

of full scale are specified in order to ensure an accurate curve. The

previous calibration procedure was defined by the type of gas divider

used for the calibration. Not all gas dividers were covered by the

previous procedure and no procedure was provided for a laboratory which

uses gas bottles. Changes to the procedure now allow the generation of

calibration data with six points that are approximately equally spaced.

Finally, analyzer response over 100% of full scale may be used if it

can be shown that readings in this range are accurate. These changes

give more flexibility without affecting the accuracy of the

calibrations.

29. Require that particulate sample filters be placed in unsealed

petri dishes during conditioning after the emissions test

(Sec. 86.1339-90). This language will help ensure that particulate

filters will be handled consistently in all laboratories and makes it

consistent with the pre-conditioning requirements. The unsealed petri

dish requirement is needed in order to have a uniform method for

handling PM filters that also eliminates the possibility of filter

contamination.

30. Eliminate the 80 hour maximum for pre-conditioning PM filters

(Sec. 86.1339-90). This change simplifies the filter pre-conditioning

procedure by eliminating the 80 hour maximum time requirement. It was

found that only the minimum 1 hour requirement was of meaningful value

for filter pre-conditioning.

31. Clarify the permitted point deletions from regression analysis

for validation statistics (Sec. 86.1341-90, Sec. 86.1341-98 and

Appendix I, paragraph (f)(2)). A table that describes the permitted

point deletions from regression analysis is simplified by removing some

language and adding three sentences. The changes will make the table

easier to understand and do not affect test results.

32. Correct an oversight regarding the calculation of cycle work

(Sec. 1341-90). This clarification adds language to Sec. 86.1341-90

that was inadvertently not included from Sec. 86.1341-84.

33. Clarify that no useful work is generated from spurious non-

zero/CITT torques that occur during idle (Sec. 86.1341-98(b) (3) &

(4)). For manual transmissions, all spurious non-zero torques at

reference idle portions of the cycle shall be set equal to zero and

included in the horsepower-hour calculation used for emission

determinations. For automatic transmissions, all spurious non-CITT

torques at reference idle portions of the cycle shall be included in

the horsepower-hour calculation used in the emission determination.

34. Clarify the calculations for converting emission measurements

from as-measured dry concentrations to wet concentrations

(Sec. 86.1342-90, Sec. 86.1342-94). An equation used to convert as-

measured dry concentrations to wet concentrations is amended in order

to correct an error in its derivation.

35. Correct an error that occurred from Sec. 86.1342-84 to

Sec. 86.1342-90 when some guidelines for converting dry measurements to

wet concentrations became subordinate to a section describing the

calculation of brake-specific fuel consumption (Sec. 86.1342-90,

Sec. 86.1342-94).

36. Clarify what calculations should be used for determining the

emission of particulate matter depending on what type of CVS sampling

system is used (Sec. 86.1343-88). The original language did not

distinguish between critical flow venturi (CFV) CVS and positive

displacement pump (PDP) CVS, which require different calculations for

determining the mass of particulate matter. The new language now

provides distinct calculations for both systems for emission

calculation purposes.

37. Add provisions for testing heavy-duty engines and light-duty

vehicles that require the manufacturer to verify that the venturi is

achieving sonic flow when using a CFV-CVS sampling system (Sec. 86.119-

90, Sec. 86.1319-84 and Sec. 86.1319-90). Having sonic flow during

emission tests, when using a CFV-CVS sampling system, is of critical

importance in order to achieve accurate and reliable emission results.

Manufacturers have two options for verifying sonic flow. The first

option involves calculating CFV pressure ratio, which must be less than

or equal to the calibration pressure ratio limit derived from the CFV

calibration data. Other sonic flow verification methods may be allowed

with prior approval from the Administrator.

38. Revise Incorporation by Reference (Sec. 86.1). Section 86.1

contains a listing of all items in part 86 which are incorporated by

reference, along with the section numbers where they are incorporated.

The SAE Recommended Practice J1937 and the standard test method ASTM

5186-91 are added to such list. In addition, several minor corrections

to section 86.1 are made. In the Gaseous Fuels Rule the changes to

section 86.1 to incorporate the standards ASTM D2163-91 and ASTM D1945-

91 were in some cases incorrect and did not properly list the part 86

sections in which these standards were incorporated.

39. Correct Certification Specifications for Diesel Fuel for Light-

Duty Vehicles and Trucks (Sec. 86.113-94). In the Gaseous Fuels Rule

(59 FR 48472) the section specifying certification fuel parameters for

light-duty vehicles and trucks (Sec. 86.113-94) was modified to include

natural gas and liquefied petroleum gas specifications. In addition to

new gaseous fuels specifications, this section was restructured to make

future additions of other fuels easier. Although these were the only

intended changes, some changes were inadvertently made to the

specifications for diesel fuel as well. Thus, in this notice such

section is being revised to correct for these inadvertent changes to

the diesel fuel specifications. Corrections involve the cetane number

and cetane index in paragraph (b)(2), and the cetane index, 90 percent

distillation point and gravity in paragraph (b)(3). These changes will

bring the diesel fuel certification specifications back to their

original state, prior to the publication of the Gaseous Fuels Rule.

40. Clarify Gaseous Fuel Standards Applicability (Sec. 86.094-8,

Sec. 86.094-9, Sec. 86.094-11, Sec. 86.096-8 and Sec. 86.096-11). In

the Gaseous Fuels Rule there were several instances where the

regulatory text did not mirror the preamble discussion concerning the

applicability of various standards to gaseous-fueled vehicles,

especially as they relate to the options on the applicability of the

standards prior to the 1997 model year. EPA is revising the regulatory

text to clarify the provisions of the Gaseous Fuels Rule regulations.

The clarifications are summarized briefly in the following sentences.

In sections 86.094-8, 86.094-9, 86.096-8 and 86.096-11, the language

concerning the crankcase emissions prohibition is being clarified to

show that it is optional for the 1994 through 1996 model years and also

optional for 1997 model year turbocharged gaseous fueled heavy-duty

engines. In sections 86.094-9 and 86.096-11 the language concerning

exhaust emission standards is being

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clarified to show that those standards are optional for gaseous-fueled

vehicles through the 1996 model year. In section 86.094-9 the language

concerning idle carbon monoxide (CO) emission standards is being

clarified to show that those standards are applicable to gaseous-fueled

engines, but optional through the 1996 model year. Finally, the section

86.094-11 language concerning smoke standards is being clarified to

show that those standards are applicable to gaseous-fueled vehicles,

but optional through the 1996 model year.

41. Clarify Exhaust Emission Calculations Sec. 86.144-94). In

section 86.144-94, the density of nonmethane hydrocarbons in natural

gas and liquefied petroleum gas is used for emission calculations. The

description of this term incorrectly specifies that it be defined

simply as the density of hydrocarbon components in the fuel. This

definition does not exclude methane, as it should. The definition is

being corrected here to refer to the density of only the nonmethane

components.

42. Clarify Changes to the Flame Ionization Detector (FID)

optimization (Sec. 86.1321-90 and Sec. 86.1321-94). More language is

incorporated to resolve some previous inconsistencies with the

procedure. For instance, the FID response now can be optimized with

respect to fuel flow or to fuel pressure. Furthermore, it is also

clarified that the optimum fuel, air, and sample pressures or flow

rates shall be recorded after their determination.

III. Environmental and Economic Impacts

EPA believes that these technical amendments will not have any

significant economic or environmental impacts. The changes have the

objective to clarify inconsistencies that might have been present in

the original rule or to allow the use of new testing equipment that

gives more flexibility, but does not affect test results.

IV. Public Participation

EPA believes that the provisions of this action are

noncontroversial since all the changes to the test procedures have been

previously discussed and resolved with the Engine Manufacturers

Association (EMA) and its members. Nonetheless, if public comments are

to be submitted, the Agency requests that wherever applicable, full

supporting data and detailed analysis should be submitted to allow EPA

to make maximum use of the comments. Commentators should provide

specific suggestions for any changes to any aspect of the regulations

that they believe need to be modified or improved. If EPA receives

adverse or critical comments regarding any specific element of this

rule, EPA will withdraw those regulations for which adverse or critical

comments were received. All comments should be directed to EPA Air

Docket, Docket No. A-96-07. The official comment period will last for

30 days following publication of this notice.

Commentators desiring to submit proprietary information for

consideration should clearly distinguish such information from other

comments to the greatest extent possible, and clearly label it

``Confidential Business Information''. Submissions containing such

proprietary information should be sent directly to the contact person

listed above, and not to the public docket, to ensure that proprietary

information is not inadvertently placed in the docket.

Information covered by such a claim of confidentiality will be

disclosed by EPA only to the extent allowed and by the procedures set

forth in 40 CFR part 2. If no claim of confidentiality accompanies the

submission when it is received by EPA, it may be made available to the

public without further notice to the commentator.

V. Statutory Authority

The statutory authority for this action is granted by Sections 202,

206, 207, 208 and 301(a) of the Clean Air Act.

VI. Administrative Designation and Regulatory Analysis

Under Executive Order 12866 (58 FR 51735 (October 4, 1993)), the

Agency must determine whether this 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:

(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, EPA believes that

this action is not a ``significant'' regulatory action within the

meaning of the Executive Order.

VII. Compliance With Regulatory Flexibility Act

EPA has determined that it is not necessary to prepare a regulatory

flexibility analysis in connection with this final rule. In support of

its proposed rule entitled Control of Emissions of Air Pollution from

Highway Heavy-Duty Engines (61 FR 33421, June 27, 1996), EPA

characterized the heavy-duty engine manufacturing industry in Chapter 3

of its Regulatory Impact Analysis (RIA). Based on that

characterization, EPA has determined that these technical amendments

will not have a significant impact on a substantial number of small

entities.

VIII. Unfunded Mandates

Under section 202 of the Unfunded Mandates Reform Act of 1995

(``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA

must prepare a written statement to accompany any rule where the

estimated costs to State, local, or tribal governments, or to the

private sector will be $100 million or more in any one year. Under

section 205, EPA must select the most cost-effective and least

burdensome alternative that achieves the objective of the rule and that

is consistent with statutory requirements. Section 203 requires EPA to

establish a plan for informing and advising any small governments that

may be significantly and uniquely impacted by the rule. EPA estimates

that the costs to State, local, or tribal governments, or the private

sector, from this rule will be less than $100 million.

IX. Paperwork Reduction Act

The technical amendments promulgated by this action do not create

or change the information collection burden under the provisions of the

Paperwork Reduction Act, 44 U.S.C. 3501 et. seq. The Office of

Management and Budget (OMB) has previously approved the information

collection requirements already contained in all the Part 86 sections

amended by this action and has assigned OMB control numbers 2060-0104

and 2060-0064.

X. Submission to Congress and the General Accounting Office

Under 5 U.S.C. 801(a)(1)(A) as added by the Small Business

Regulatory Enforcement Fairness Act of 1996, EPA

[[Page 47119]]

submitted a report containing this rule and other required information

to the U.S. Senate, the U.S. House of Representatives and the

Comptroller General of the General Accounting Office prior to

publication of this rule in today's Federal Register. This rule is not

a ``major rule'' as defined by 5 U.S.C. 804(2).

XI. Copies of Rulemaking Documents

The preamble and regulatory language are available in the public

docket as described under ADDRESSES above and is also available

electronically on the Technology Transfer Network (TTN), which is an

electronic bulletin board system (BBS) operated by EPA's Office of Air

Quality Planning and Standards and via the Internet. The service is

free of charge, except for the cost of the phone call.

A. Technology Transfer Network (TTN)

Users are able to access and download TTN files on their first call

using a personal computer and modem per the following information.

TTN BBS: 919-541-5742 (1200-14400 bps, no parity, 8 data bits, 1 stop

bit)

Voice Helpline: 919-541-5384

Also accessible via Internet: TELNET ttnbbs.rtpnc.epa.gov

Off-line: Mondays from 8:00 AM to 12:00 Noon ET

A user who has not called TTN previously will first be required to

answer some basic informational questions for registration purposes.

After completing the registration process, proceed through the

following menu choices from the Top Menu to access information on this

rulemaking.

GATEWAY TO TTN TECHNICAL AREAS (Bulletin Boards)

OMS--Mobile Sources Information

Rulemaking & Reporting

Heavy-duty/Diesel

File area #1 . . . Heavy-duty Truck and Bus Standards

At this point, the system will list all available files in the

chosen category in reverse chronological order with brief descriptions.

To download a file, select a transfer protocol that is supported by the

terminal software on your own computer, then set your own software to

receive the file using that same protocol.

If unfamiliar with handling compressed (i.e. ZIP'ed) files, go to

the TTN top menu, System Utilities (Command: 1) for information and the

necessary program to download in order to unZIP the files of interest

after downloading to your computer. After getting the files you want

onto your computer, you can quit the TTN BBS with the oodbye

command.

Please note that due to differences between the software used to

develop the document and the software into which the document may be

downloaded, changes in format, page length, etc. may occur.

B. Internet

Rulemaking documents may be found on the Internet as follows:

World Wide Web: http://www.epa.gov/omswww

FTP: ftp://ftp.epa.gov Then CD to the /pub/gopher/OMS/ directory

Gopher: gopher://gopher.epa.gov:70/11/Offices/Air/OMS

Alternatively, go to the main EPA gopher, and follow the menus:

gopher.epa.gov

EPA Offices and Regions

Office of Air and Radiation

Office of Mobile Sources

List of Subjects

40 CFR Part 9

Reporting and recordkeeping requirements.

40 CFR Part 86

Environmental protection, Administrative practice and procedures,

Air pollution control, Confidential business information, Gasoline,

Incorporation by reference, Labeling, Motor vehicles, Motor vehicle

pollution, Reporting and recordkeeping requirements.

Dated: August 18, 1997.

Carol M Browner,

Administrator.

For the reasons set forth in the preamble, parts 9 and 86 of title

40 of chapter I of the Code of Federal Regulations are amended as

follows:

PART 9--[AMENDED]

1. The authority citation for part 9 continues to read as follows:

Authority: 7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001, 2003,

2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33

U.S.C. 1251 et seq., 1311, 1313d, 1314, 1321, 1326, 1330, 1344, 1345

(d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR 1971-1975 Comp. p.

973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g, 300g-1, 300g-2,

300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2, 300j-3, 300j-4,

300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542, 9601-9657,

11023, 11048.

1a. Section 9.1 is amended in the table by adding in numerical

order new entries under the center heading ``Control of Air Pollution

from New and In-Use Motor Vehicles and New and In-Use Motor Vehicle

Engines: Certification and Test Procedures,'' to read as follows:

Sec. 9.1 OMB approvals under the Paperwork Reduction Act.

* * * * *

40 CFR citation OMB control no.

* * * * *

Control of Air Pollution From New and In-Use Motor Vehicles and New and

In-Use Motor Vehicle Engines: Certification and Test Procedures

* * * * *

86.1313-98................................................. 2060-0104

* * * * *

86.1327-98................................................. 2060-0104

* * * * *

86.1341-98................................................. 2060-0104

* * * * *

PART 86--CONTROL OF AIR POLLUTION FROM NEW AND IN-USE MOTOR

VEHICLES AND NEW AND IN-USE MOTOR VEHICLE ENGINES: CERTIFICATION

AND TEST PROCEDURES

1b. The authority citation for part 86 is revised to read as

follows:

Authority: 42 U.S.C. 7401-7671q.

2. In Sec. 86.1 the tables in paragraphs (b)(1) and (b)(2) are

amended by adding an entry for ASTM D5186-91 after ASTM E29-90, and by

revising the entries for ASTM D2163-91 and ASTM D1945-91 to read as

follows:

Sec. 86.1 Reference materials.

* * * * *

(b) * * *

(1) * * *

------------------------------------------------------------------------

Document number and name 40 CFR part 86 reference

------------------------------------------------------------------------

* * * * *

ASTM D5186-91, Standard Test Method for 86.1313-91, 86.1313-94,

Determination of Aromatic Content of 86.1313-98.

Diesel Fuels by Supercritical Fluid

Chromatography.

ASTM D2163-91, Standard Test Method for 86.113-94; 86.1213-94;

Analysis of Liquefied Petroleum (LP) 86.1313-94.

Gases and Propane Concentrates by Gas

Chromatography.

[[Page 47120]]

ASTM D1945-91, Standard Test Method for 86.113-94; 86.513-94;

Analysis of Natural Gas By Gas 86.1213-94; 86.1313-94.

Chromatography.

------------------------------------------------------------------------

(2) * * *

------------------------------------------------------------------------

Document No. and name 40 CFR part 86 reference

------------------------------------------------------------------------

* * * * *

SAE Recommended Practice J1937, November 86.1330-84; 86.1330-90.

1989, Engine Testing with Low Temperature

Charge Air Cooler Systems in a

Dynamometer Test Cell.

------------------------------------------------------------------------

* * * * *

3. Section 86.094-8 of subpart A is amended by revising paragraph

Sec. 86.094-8 Emission standards for 1994 and later model year light-

duty vehicles.

* * * * *

atmosphere from any 1994 and later model year Otto-cycle, or methanol-

or gaseous-fueled diesel light-duty vehicle. This requirement is

optional for 1994 through 1996 model year gaseous-fueled light-duty

vehicles.

* * * * *

4. Section 86.094-9 of subpart A is amended by revising paragraphs

(a)(1)(i) introductory text, (a)(1)(ii) introductory text, (a)(1)(iii)

and (c), to read as follows:

Sec. 86.094-9 Emission standards for 1994 and later model year light-

duty trucks.

(a) * * *

(1) * * *

(i) Light light-duty trucks. Exhaust emission from 1994 and later

model year light light-duty trucks shall meet all standards in Tables

A94-8, A94-9, A94-11 and A94-12 in the rows designated with the

applicable fuel type and loaded vehicle weight, according to the

implementation schedule in Tables A94-7 and A94-10 as follows (optional

for 1994 through 1996 model year gaseous-fueled light light-duty

trucks):

* * * * *

(ii) Heavy light-duty trucks. Exhaust emissions from 1994 and later

model year heavy light-duty trucks shall meet all standards in Tables

A94-14 and A94-15 in the rows designated with the applicable fuel type

and loaded vehicle weight or adjusted loaded vehicle weight, as

applicable, according to the implementation schedule in Table A94-13,

as follows (optional for 1994 through 1996 model year gaseous-fueled

heavy light-duty trucks):

* * * * *

(iii) Exhaust emissions of carbon monoxide from 1994 and later

model year light-duty trucks shall not exceed 0.50 percent of exhaust

gas flow at curb idle at a useful life of 11 years or 120,000 miles,

whichever first occurs (for Otto-cycle, and methanol-and gaseous-fueled

diesel light-duty trucks only--optional for 1994 through 1996 model

year gaseous-fueled light-duty trucks).

* * * * *

atmosphere from any 1994 and later model year light-duty truck. This

requirement is optional for 1994 through 1996 model year gaseous-fueled

light-duty trucks.

* * * * *

5. Section 86.094-11 of subpart A is amended by revising paragraph

(b)(1) introductory text to read as follows:

Sec. 86.094-11 Emission standards for 1994 and later model year diesel

heavy-duty engines and vehicles.

* * * * *

(b)(1) The opacity of smoke from new 1994 and later model year

diesel heavy-duty engines shall not exceed (optional for 1994 through

1996 model year gaseous-fueled diesel heavy-duty engines):

* * * * *

6. Section 86.096-8 of subpart A is amended by revising paragraph

Sec. 86.096-8 Emission standards for 1996 and later model year light-

duty vehicles.

* * * * *

atmosphere from any 1996 and later model year Otto-cycle, or methanol-

or gaseous-fueled diesel light-duty vehicle. This requirement is

optional for 1996 model year gaseous-fueled light-duty vehicles.

* * * * *

7. Section 86.096-11 of subpart A is amended by revising paragraphs

(a) introductory text and (c) to read as follows:

Sec. 86.096-11 Emission standards for 1996 and later model year diesel

heavy-duty engines and vehicles.

(a) Exhaust emissions from new 1996 and later model year diesel

heavy-duty engines shall not exceed the following (optional for 1996

model year gaseous-fueled diesel heavy-duty engines):

* * * * *

atmosphere from any new 1996 or later model year methanol-or gaseous-

fueled diesel, or any naturally aspirated diesel heavy-duty engine. For

petroleum-fueled engines only, this provision does not apply to engines

using turbochargers, pumps, blowers, or superchargers for air

induction. This provision is optional for all 1996 model year gaseous-

fueled diesel heavy-duty engines, and for 1997 model year gaseous-

fueled diesel heavy-duty engines using turbochargers, pumps, blowers or

superchargers for air induction.

* * * * *

8. Section 86.113-94 of subpart B is amended by revising the tables

after paragraphs (b)(2) and (b)(3) to read as follows:

Sec. 86.113-94 Fuel specifications.

* * * * *

(b) * * *

(2) * * *

----------------------------------------------------------------------------------------------------------------

Item ASTM test method No. Type 2-D

----------------------------------------------------------------------------------------------------------------

Cetane Number........................... ............................ D613 40-48

Cetane Index............................ ............................ D976 40-48

Distillation range:

IBP................................... deg.F D86 340-400

( deg.C) ....................... (171.1-204.4)

10 pct. point......................... deg.F D86 400-460

( deg.C) ....................... (204.4-237.8)

50 pct. point......................... deg.F D86 470-540

( deg.C) ....................... (243.3-282.2)

[[Page 47121]]

90 pct. point......................... deg.F D86 560-630

( deg.C) ....................... (293.3-332.2)

EP.................................... deg.F D86 610-690

( deg.C) ....................... (321.1-365.6)

Gravity................................. deg.API D287 32-37

Total sulfur............................ pct. D2622 0.03-0.05

Hydrocarbon composition:

Aromatics, min........................ pct. D1319 27

Paraffins, Naphthenes, Olefins........ ............................ D1319 (1)

Flashpoint, min......................... deg.F D93 130

( deg.C) ....................... (54.4)

Viscosity, centistokes.................. ............................ D445 2.0-3.2

----------------------------------------------------------------------------------------------------------------

\1\ Remainder.

(3) * * *

----------------------------------------------------------------------------------------------------------------

Item ASTM test method No. Type 2-D

----------------------------------------------------------------------------------------------------------------

Cetane Number........................... ............................ D613 38-58

Cetane Index............................ ............................ D976 min. 40

Distillation range:

90 pct. point......................... deg.F D86 540-630

( deg.C) ....................... (282.2-343.3)

Gravity................................. deg.API D287 30-39

Total sulfur............................ pct. D2622 0.03-0.05

Flashpoint, min......................... deg.F D93 130

( deg.C) ....................... (54.4)

Viscosity............................... centistokes D445 1.5-4.5

----------------------------------------------------------------------------------------------------------------

* * * * *

9. Section 86.119-90 of subpart B is amended by revising paragraph

(b)(3) and adding paragraph (b)(8) to read as follows:

Sec. 86.119-90 CVS calibration.

* * * * *

(b) * * *

(3) Measurements necessary for flow calibration are as follows:

Calibration Data Measurements

--------------------------------------------------------------------------------------------------------------------------------------------------------

Parameter Symbol Units Tolerances

--------------------------------------------------------------------------------------------------------------------------------------------------------

Barometric pressure (corrected)....... Pb Inches Hg (kPa) .01 in Hg (.034 kPa).

Air temperature, flowmeter............ ETI deg.F ( deg.C) .25 deg.F (.14 deg.C).

Pressure depression upstream of LFE... EPI Inches H2O (kPa) .05 in H2O (.012 kPa).

Pressure drop across LFE matrix....... EDP Inches H2O (kPa) .005 in H2O (.001 kPa).

Air flow.............................. Qs Ft3/min. (m3/min,) .5 pct.

CFV inlet depression.................. PPI Inches fluid (kPa) .13 in fluid (.055 kPa).

CFV outlet pressure................... PPO Inches Hg (kPa) 0.05 in. Hg (0.17 kPa)

Temperature at venturi inlet.......... Tv deg.F ( deg.C) 0.5 deg.F (0.28 deg.C).

Specific gravity of manometer fluid Sp. Gr .................................... .................................................

(1.75 oil).

--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * *

(8) Calculation of a parameter for monitoring sonic flow in the CFV

during exhaust emissions tests:

(i) Option 1. (A) CFV pressure ratio. Based upon the calibration

data selected to meet the criteria for paragraphs (d)(7)(iv) and (v),

in which Kv is constant, select the data values associated

with the calibration point with the lowest absolute venturi inlet

pressure. With this set of calibration data, calculated the following

CFV pressure ratio limit, Prratio-lim:

[GRAPHIC] [TIFF OMITTED] TR05SE97.000

Where:

Pin-cal=Venturi inlet pressure (PPI in absolute pressure

units), and

Pout-cal=Venturi outlet pressure (PPO in absolute pressure

units), measured at the exit of the venturi diffuser outlet.

(B) The venturi pressure ratio (Prratio-i) during all

emissions tests must be less than, or equal to, the calibration

pressure ratio limit (Prratio-lim) derived from the CFV

calibration data, such that:

[GRAPHIC] [TIFF OMITTED] TR05SE97.001

Where:

Pin-i and Pout-i are the venturi inlet and outlet

pressures, in absolute

[[Page 47122]]

pressure units, at each i-th interval during the emissions test.

(ii) Option 2. Other methods: With prior Administrator approval,

any other method may be used that assure that the venturi operates at

sonic conditions during emissions tests, provided the method is based

upon sound engineering principles.

* * * * *

10. Section 86.144-94 of subpart B is amended by revising paragraph

(c)(8)(ii)(B) to read as follows:

Sec. 86.144-94 Calculations; exhaust emissions.

* * * * *

(8) * * *

(ii) * * *

(B) For natural gas and liquefied petroleum gas fuel;

DensityNMHC=1.1771(12.011+H/C(1.008))g/ft3-carbon

atom (0.04157(12.011+H/C(1.008))kg/m3-carbon atom), where H/

C is the hydrogen to carbon ratio of the non-methane hydrocarbon

components of the test fuel, at 68 deg.F (20 deg.C) and 760 mm Hg

(101.3 kPa) pressure.

* * * * *

11. Section 86.884-7 of subpart I is amended by revising paragraphs

(a)(2)(i), (a)(3) and (a)(4) to read as follows:

Sec. 86.884-7 Dynamometer operation cycle for smoke emission tests.

(a) * * *

(1) * * *

(2) Acceleration mode. (i) The engine speed shall be increased to

200 50 rpm above the measured free idle speed measured at

the point where the throttle begins to move from part-throttle to the

full throttle position. The speed anywhere during this mode should not

exceed this checkpoint speed by more than 50 rpm. The duration of this

first acceleration shall be three seconds or less measured from the

point where the speed first begins to increase above idle to the point

where the throttle reaches full open position.

* * * * *

(3) Lugging mode. (i) Immediately upon the completion of the

preceding acceleration mode, the dynamometer controls shall be adjusted

to permit the engine to develop maximum horsepower at rated speed. This

transition period shall be 50 to 60 seconds in duration. During the

last 10 seconds of this period, the average engine speed shall be

maintained within 50 rpm of the rated speed, and the average observed

power (corrected, if necessary, to rating conditions) shall be no less

than 95 percent of the maximum horsepower developed during the

preconditioning prior to the smoke cycle.

(ii) With the throttle remaining in the fully open position, the

dynamometer controls shall be adjusted gradually so that the engine

speed is reduced to the intermediate speed. This lugging operation

shall be performed smoothly over a period of 355 seconds.

The rate of slowing of the engine shall be linear, within 100 rpm, as

specified in Sec. 86.884-13(c).

(4) Engine unloading. Within five seconds of completing the

preceding lugging mode, the dynamometer and engine controls shall be

returned to the idle position described in paragraph (a)(1) of this

section. The engine must be at free idle condition within one minute

after completion of the lugging mode.

* * * * *

12. Section 86.884-8 of subpart I is amended by revising paragraph

Sec. 86.884-8 Dynamometer and engine equipment.

* * * * *

10 to 32 feet from the exhaust manifold(s), turbocharger outlet(s),

exhaust aftertreatment device(s), or crossover junction (on Vee

engines), whichever is farthest downstream. The smoke exhaust system

can share the same hardware required in part 86, subpart N,

Sec. 86.1327-84(f)(2), insofar as that hardware also meets the

following smoke test requirements. The smoke exhaust system shall

present an exhaust backpressure within +0.2 inch Hg of the upper limit

at maximum rated horsepower, as established by the engine manufacturer

in his sales and service literature for vehicle application. The

following options may also be used:

(1) For engines with multiple exhaust outlets, join the exhaust

outlets together into a single exhaust system and install the

smokemeter 10 to 32 feet downstream from the junction of the individual

exhaust outlets, or exhaust aftertreatment device(s), whichever is

farthest downstream.

(2) For engines with multiple exhaust outlets, install a smokemeter

in each of the exhaust pipes 10 to 32 feet downstream from each exhaust

manifold, turbocharger outlet, or exhaust aftertreatment device,

whichever is farthest downstream.

(3) For engines with multiple exhaust outlets, install a smokemeter

on the exhaust pipe which produces the highest smoke levels 10 to 32

feet downstream from the exhaust manifold, turbocharger outlet, or

exhaust aftertreatment device, whichever is farthest downstream. It may

be required to make smoke measurements from other exhaust outlets if

deemed appropriate by the Administrator.

(4) When utilizing an end-of-line smokemeter, the terminal two feet

of the exhaust pipe used for smoke measurement shall be of a circular

cross section and be free of elbows and bends. The end of the pipe

shall be cut off squarely. The terminal two feet of the exhaust pipe

shall have a nominal inside diameter in accordance with the engine

being tested, as specified below:

------------------------------------------------------------------------

Standard Exhaust Pipe Diameter,

Maximum Rated Horsepower inches (meters)

------------------------------------------------------------------------

Less than 101.................... 2 (0.051)

101 to 200....................... 3 (0.076)

201 to 300....................... 4 (0.102)

301 to 500....................... 5 (0.127)

501 or more...................... 5 (0.127)\1\ or 6 (0.152)\2\

------------------------------------------------------------------------

\1\ Applicable for on-highway engines.

\2\ Applicable for nonroad engines.

(5) When utilizing an in-line smokemeter, there shall be no change

in the exhaust pipe diameter within 3 exhaust pipe diameters before or

after the centerline of the smokemeter optics. Within 6 exhaust pipe

diameters upstream of the centerline of the smokemeter optics, no

change in exhaust pipe diameter may exceed a 12 degree half-angle.

* * * * *

13. Section 86.884-9 of subpart I is amended by revising paragraphs

(b)(2)(i), (b)(2)(ii), (b)(2)(iii), (b)(2)(iv), and (c)(1) to read as

follows:

Sec. 86.884-9 Smoke measurement system.

* * * * *

(b) * * *

(2) * * *

(i) It is positioned so that a built-in light beam traverses the

exhaust smoke plume at right angles to the axis of the exhaust stream.

(ii) The smokemeter light source shall be an incandescent lamp with

a color temperature range of 2800K to 3250K, or a light source with a

spectral peak between 550 to 570 nanometers.

(iii) The light output is collimated to a beam with a maximum

diameter of 1.125 inches and an included angle of divergence within a

6 deg. included angle.

(iv) The light detector shall be a photocell or photodiode. If the

light source is an incandescent lamp, the detector shall have a

spectral response similar to the photopic curve of the human eye (a

maximum response in the range of 550 to 570 nanometers, to less than 4

percent of that maximum

[[Page 47123]]

response below 430 nanometers and above 680 nanometers).

* * * * *

shall be mounted radially to the exhaust pipe so that the measurement

will be made at right angles to the axis of the exhaust plume. For an

end-of-line smokemeter the distance from the optical centerline to the

exhaust pipe outlet shall be 1 0.25 inch. The full flow of

the exhaust stream shall be centered between the source and the

detector apertures (or windows and lenses) and on the axis of the light

beam.

* * * * *

14. Section 86.884-10 of subpart I is amended by revising paragraph

(a)(8) to read as follows:

Sec. 86.884-10 Information.

* * * * *

(a) * * *

(8) Idle rpm.

* * * * *

15. Section 86.884-13 of subpart I is amended by revising

paragraphs (b)(6)(ii) and (b)(6)(iii) to read as follows:

Sec. 86.884-13 Data analysis.

* * * * *

(b) * * *

(6) * * *

(ii) Average speed during the last 10 seconds shall be within

50 rpm of rated speed.

(iii) Average observed power during the last 10 seconds shall be at

least 95 percent of the horsepower developed during the preconditioning

mode.

* * * * *

16. Section 86.884-14 of subpart I is revised to read as follows:

Sec. 86.884-14 Calculations.

(a) If the measured half-second opacity values were obtained with a

smokemeter with an optical path length different than shown in the

table in Sec. 86.884-8(c), then convert the measured half-second values

or the original instantaneous values to the appropriate equivalent

optical path length values specified in the table. Convert the opacity

values according to the following equations:

Ns=100 x (1-(1-Nm/

100)Ls/Lm)

Lm and Ls must use consistent units in the above

equation

Where:

Nm=Measured half-second value for conversion, percent

opacity

Lm=Measuring smokemeter optical path length, meters

Ls=Standard optical path length corresponding with engine

power, n

Ns=Standard half-second value, percent opacity

(b) Average the 45 readings in Sec. 86.884-13(d)(3) or the

equivalent converted values from paragraph (a) of this section if

appropriate, and designate the value as ``A''. This is the value for

the engine acceleration mode.

equivalent converted values from paragraph (a) of this section if

appropriate, and designate the value as ``B''. This is the value for

the engine lugging mode.

(d) Average the 9 readings in Sec. 86.884-13(d)(5) or the

equivalent converted values from paragraph (a) of this section if

appropriate, and designate the value as ``C''. This is the value for

the peaks in either mode.

(e)(1) If multiple smokemeters were used, the half-second values

for each mode from each smokemeter shall be combined and the calculated

average based upon the total number of combined values.

(2) For example, if two smokemeters were used for acceleration mode

data, 45 half-second values in each data set from both smokemeters

would be combined to form a data set of 90 values, which would then be

averaged.

17. Section 86.1008-90 of subpart K is amended by adding paragraph

(a)(1)(iii) to read as follows:

Sec. 86.1008-90 Test procedures.

(a)(1)(i) * * *

(iii) During the testing of heavy-duty diesel engines, the

manufacturer shall decide for each engine, prior to the start of the

initial cold cycle, whether the measurement of background particulate

is required for the cold and hot cycles to be valid. The manufacturer

may choose to have different requirements for the cold and hot cycles.

If a manufacturer chooses to require the measurement of background

particulate, failure to measure background particulate shall void the

test cycle regardless of the test results. If a test cycle is void, the

manufacturer shall retest using the same validity requirements of the

initial test.

* * * * *

18. Section 86.1008-96 of subpart K is amended by revising

paragraph (a)(1) to read as follows:

Sec. 86.1008-96 Test procedures

* * * * *

(a)(1)(i) For heavy-duty engines, the prescribed test procedure is

the Federal Test Procedure, as described in subparts N, I, and P of

this part.

(ii) During the testing of heavy-duty diesel engines, the