[Federal Register Volume 62, Number 172 (Friday, September 5, 1997)]
[Rules and Regulations]
[Pages 47114-47136]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-23352]



[[Page 47113]]

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Part II





Environmental Protection Agency





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40 CFR Parts 9 and 86



Test Procedures for Heavy-Duty Engines, and Light-Duty Vehicles and 
Trucks, and Emission Standard Provisions for Gaseous Fueled Vehicles, 
and Engines, Amendments; Final Rule

  Federal Register / Vol. 62, No. 172 / Friday, September 5, 1997 / 
Rules and Regulations  

[[Page 47114]]


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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 
Register withdrawing any regulation for which adverse or critical 
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

[[Page 47115]]

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

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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

[[Page 47118]]

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
    <5> Heavy-duty/Diesel
    <1> 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 
(c) to read as follows:


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

* * * * *
    (c) No crankcase emissions shall be discharged into the ambient 
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).
* * * * *
    (c) No crankcase emissions shall be discharged into the ambient 
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 
(c) to read as follows:


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

* * * * *
    (c) No crankcase emissions shall be discharged into the ambient 
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):
* * * * *
    (c) No crankcase emissions shall be discharged into the ambient 
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.

* * * * *
    (c) * * *
    (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 
(c) to read as follows:


Sec. 86.884-8  Dynamometer and engine equipment.

* * * * *
    (c) An exhaust system with an appropriate type of smokemeter placed 
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).
* * * * *
    (c) Assembling equipment. (1) The optical unit of the smokemeter 
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.
    (c) Average the 15 readings in Sec. 86.884-13(d)(4) or the 
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 
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.
* * * * *
    19. Section 86.1008-2001 of subpart K is amended by adding 
paragraph (a)(1)(iii) to read as follows:


Sec. 86.1008-2001  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.
* * * * *
    20. Section 86.1111-87 is amended by redesignating paragraph (a)(4) 
as paragraph (a)(5) and adding a new paragraph (a)(4) to read as 
follows:


Sec. 86.1111-87  Test procedures for PCA testing.

* * * * *
    (a) * * *
    (4) 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.
* * * * *
    21. Section 86.1310-90 of subpart N is amended by revising 
paragraphs (b)(1)(iv)(C), (b)(3)(v), (b)(3)(vi), (b)(6)

[[Page 47124]]

introductory text, and (b)(7)(iv) to read as follows:


Sec. 86.1310-90  Exhaust gas sampling and analytical system; diesel 
engines.

* * * * *
    (b) * * *
    (1) * * *
    (iv) * * *
    (C) Primary dilution air may be sampled to determine background 
particulate levels, which can then be subtracted from the values 
measured in the diluted exhaust stream. 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, if 
used.
* * * * *
    (3) * * *
    (v) The continuous HC sampling system shall consist of a probe 
(which must raise the sample to the specified temperature) and, where 
used, a sample transfer system (which must maintain the specified 
temperature). The continuous hydrocarbon sampling system (exclusive of 
the probe) shall:
    (A) Maintain a wall temperature of 464K  11K (191 deg.C 
 11 deg.C) as measured at every separately controlled 
heated component (i.e., filters, heated line sections), using permanent 
thermocouples located at each of the separate components.
    (B) Have a wall temperature of 464K  11K (191 deg.C 
 11 deg.C) over its entire length. The temperature of the 
system shall be demonstrated by profiling the thermal characteristics 
of the system at initial installation and after any major maintenance 
performed on the system. The temperature profile of the HC sampling 
system shall be demonstrated by inserting thermocouple wires (typically 
Teflon coated for ease of insertion) into the sampling 
system assembled in-situ where possible, using good engineering 
judgement. The wire should be inserted up to the HFID inlet. Stabilize 
the sampling system heaters at normal operating temperatures. Withdraw 
the wires in increments of 5 cm to 10 cm (2 inches to 4 inches) 
including all fittings. Record the stabilized temperature at each 
position. The system temperature will be monitored during testing at 
the locations and temperature described in Sec. 86.1310-90(b)(v)(A). 
Comment: It is understood that profiling of the sample line can be done 
under flowing conditions also as required with the probe.
    (C) Maintain a gas temperature of 464K 11K (191 deg.C 
11 deg.C) immediately before the heated filter and HFID. 
These gas temperatures will be determined by a temperature sensor 
located immediately upstream of each component.
    (vi) The continuous hydrocarbon sampling probe shall:
    (A) Be defined as the first 25.4 cm (10 in) to 76.2 cm (30 in) of 
the continuous hydrocarbon sampling system.
    (B) Have a 0.483 cm (0.19 in) minimum inside diameter.
    (C) Be installed in the primary dilution tunnel at a point where 
the dilution air and exhaust are well mixed (i.e., approximately 10 
tunnel diameters downstream of the point where the exhaust enters the 
dilution tunnel).
    (D) Be sufficiently distant (radially) from other probes and the 
tunnel wall so as to be free from the influence of any wakes or eddies.
    (E) Increase the gas stream temperature to 464K 11K 
(191 deg.C 11 deg.C) by the exit of the probe. The ability 
of the probe to accomplish this shall be demonstrated at typical sample 
flow rates using the insertion thermocouple technique at initial 
installation and after any major maintenance. Compliance with the 
temperature specification shall be demonstrated by monitoring during 
each test the temperature of either the gas stream or the wall of the 
sample probe at its terminus.
* * * * *
    (6) Particulate sampling system. The particulate collection system 
must be configured in either of two ways. The single-dilution method 
collects a proportional sample from the primary tunnel, and then passes 
this sample through the collection filter. The double-dilution method 
collects a proportional sample from the primary tunnel, and then 
transfers this sample to a secondary dilution tunnel where the sample 
is further diluted; the double-diluted sample is then passed through 
the collection filter. Proportionality (i.e., mass flow ratio) between 
the primary tunnel flow rate and the sample flow rate must be 
maintained within 5 percent. The requirements for these two 
systems are:
* * * * *
    (7) * * *
    (iv) It is recommended that the filter loading should be maximized 
consistent with other temperature requirements and the requirement to 
avoid moisture condensation. A filter pair loading of 1 mg is typically 
proportional to a 0.1 g/bhp-hr emission level. All particulate filters, 
reference filters, and background filters shall be handled in pairs 
during all weighing operations for emissions testing.
* * * * *
    22. Section 86.1312-88 of subpart N is amended by revising 
paragraph (a) to read as follows:


Sec. 86.1312-88  Weighing chamber and microgram balance specifications.

    (a) Ambient conditions. (1) Temperature. The ambient temperature of 
the chamber (or room) in which the particulate filters are conditioned 
and weighed shall be maintained at 295 K  3 K (22  deg.C 
 3  deg.C) during all filter conditioning and weighing.
    (2) Humidity. The humidity of the chamber (or room) in which the 
particulate filters are conditioned and weighed shall be maintained at 
a dew point temperature of 282.5 K  3 K (9.4  deg.C 
 3  deg.C) and a relative humidity of 45% 8%. 
Either the dew point temperature or the relative humidity or both may 
be averaged over the preceding 10 minute period on a moving average 
basis.
    (3) The chamber (or room) environment shall be free of any ambient 
contaminates (such as dust) that would settle on the particulate 
filters during their stabilization. It is required that at least two 
unused reference filter pairs remain in the weighing room at all times 
in covered (to reduce dust contamination) but unsealed (to permit 
humidity exchange) petri dishes. These reference filter pairs shall be 
placed in the same general area as the sample filters. These reference 
filter pairs shall be weighed within 4 hours of, but preferably at the 
same time as, the sample filter pair weighings.
    (4) If the average weight of the reference filter pairs changes 
between sample filter weighings by more than 40 micrograms, then all 
sample filters and background filters in the process of stabilization 
shall be discarded and the emissions tests repeated.
    (5) If the room (or chamber) environmental conditions are not met, 
then the filters shall remain in the conditioning room for at least one 
hour after correct conditions are met prior to weighing.
    (6) The reference filter pairs shall be changed at least once a 
month, but never between clean and used weighings of a given sample 
filter pairs. More than one set of reference filter pair may be used. 
The reference filters shall be the same size and material as the sample 
filters.
* * * * *
    23. Section 86.1313-91 of subpart N is amended by revising 
paragraph (b)(2) including Table N91-2 to read as follows:


Sec. 86.1313-91  Fuel specifications.

* * * * *

[[Page 47125]]

    (b) * * *
    (2) Petroleum fuel for diesel engines meeting the specifications in 
Table N91-2, or substantially equivalent specifications approved by the 
Administrator, shall be used in exhaust emissions testing. The grade of 
petroleum fuel used shall be commercially designated as ``Type 2-D'' 
grade diesel fuel except that fuel commercially designated as ``Type 1-
D'' grade diesel fuel may be substituted provided that the manufacturer 
has submitted evidence to the Administrator demonstrating to the 
Administrator's satisfaction that this fuel will be the predominant in-
use fuel. Such evidence could include such things as copies of signed 
contracts from customers indicating the intent to purchase and use 
``Type 1-D'' grade diesel fuel as the primary fuel for use in the 
engines or other evidence acceptable to the Administrator.

                                                   Table N91-2                                                  
----------------------------------------------------------------------------------------------------------------
                   Item                                   ASTM                    Type 1-D          Type 2-D    
----------------------------------------------------------------------------------------------------------------
Cetane Number............................  D613                                          48-54             42-50
Cetane Index.............................  D86                                           40-54             40-48
Distillation range:                                                                                             
    IBP  deg.F...........................  D86                                         330-390           340-400
    ( deg.C).............................  .................................     (165.6-198.9)     (171.1-204.4)
    10 percent point,  deg.F.............  D86                                         370-430           400-460
    ( deg.C).............................  .................................     (187.8-221.1)     (204.4-237.8)
    50 percent point,  deg.F.............  D86                                         410-480           470-540
    ( deg.C).............................  .................................       (210-248.9)     (243.3-282.2)
    90 percent point,  deg.F.............  D86                                         460-520           560-630
    ( deg.C).............................  .................................     (237.8-271.1)     (293.3-332.2)
    EP,  deg.F...........................  D86                                         500-560           610-690
    ( deg.C).............................  .................................     (260.0-293.3)     (321.1-365.6)
Gravity,  deg.API........................  D287                                          40-44             32-37
Total Sulfur, percent....................  D2622                                     0.08-0.12         0.08-0.12
Hydrocarbon composition:                                                                                        
    Aromatics, pct.......................  D1319 or D5186                                \1\ 8            \1\ 27
    Paraffins, Naphthenes, Olefins.......  D1319                                       ( \2\ )           ( \2\ )
Flashpoint,  deg.F.......................  D93                                             120               130
    ( deg.C).............................  .................................            (48.9)            (54.4)
    (minimum)............................  .................................  ................  ................
Viscosity, Centistokes...................  D445                                        1.6-2.0           2.0-3.2
----------------------------------------------------------------------------------------------------------------
\1\ Minimum.                                                                                                    
\2\ Remainder.                                                                                                  

* * * * *
    24. Section 86.1313-94 of subpart N is amended by revising 
paragraph (b)(2) including Table N94-2 to read as follows:


Sec. 86.1313-94  Fuel specifications.

* * * * *
    (b) * * *
    (2) Petroleum fuel for diesel engines meeting the specifications in 
Table N94-2, or substantially equivalent specifications approved by the 
Administrator, shall be used in exhaust emissions testing. The grade of 
petroleum fuel used shall be commercially designated as ``Type 2-D'' 
grade diesel fuel except that fuel commercially designated at ``Type 1-
D'' grade diesel fuel may be substituted provided that the manufacturer 
has submitted evidence to the Administrator demonstrating to the 
Administrator's satisfaction that this fuel will be the predominant in-
use fuel. Such evidence could include such things as copies of signed 
contracts from customers indicating the intent to purchase and use 
``Type 1-D'' grade diesel fuel as the primary fuel for use in the 
engines or other evidence acceptable to the Administrator.

                                                   Table N94-2                                                  
----------------------------------------------------------------------------------------------------------------
                   Item                                   ASTM                    Type 1-D          Type 2-D    
----------------------------------------------------------------------------------------------------------------
Cetane Number............................  D613                                          40-54             40-48
Cetane Index.............................  D976                                          40-54             40-48
Distillation range:                                                                                             
    IBP  deg.F...........................  D86                                         330-390           340-400
    ( deg.C).............................  .................................     (165.6-198.9)     (171.1-204.4)
    10 percent point,  deg.F.............  D86                                         370-430           400-460
    ( deg.C).............................  (187.8-221.1)                         (204.4-237.8)                  
    50 percent point,  deg.F.............  D86                                         410-480           470-540
    ( deg.C).............................  .................................       (210-248.9)     (243.3-282.2)
    90 percent point,  deg.F.............  D86                                         460-520           560-630
    ( deg.C).............................  .................................     (237.8-271.1)     (293.3-332.2)
    EP,  deg.F...........................  D86                                         500-560           610-690
    ( deg.C).............................  .................................     (260.0-293.3)     (321.1-365.6)
Gravity,  deg.API........................  D287                                          40-44             32-37
Total Sulfur, percent....................  D2622                                     0.03-0.05         0.03-0.05
Hydrocarbon composition:                                                                                        
    Aromatics, pct.......................  D1319 or D5186                                \1\ 8            \1\ 27
    Paraffins, Naphthenes, Olefins.......  D1319                                       ( \2\ )           ( \2\ )

[[Page 47126]]

                                                                                                                
Flashpoint,  deg.F.......................  D93                                             120               130
    ( deg.C).............................  .................................            (48.9)            (54.4)
    (minimum)............................  .................................  ................  ................
Viscosity, Centistokes...................  D445                                        1.6-2.0           2.0-3.2
----------------------------------------------------------------------------------------------------------------
\1\ Minimum.                                                                                                    
\2\ Remainder.                                                                                                  

* * * * *
    25. Section 86.1313-98 is added to subpart N to read as follows:


Sec. 86.1313-98  Fuel specifications.

    Section 86.1313-98 includes text that specifies requirements that 
differ from Sec. 86.1313-94. Where a paragraph in Sec. 86.1313-94 is 
identical and applicable to Sec. 86.1313-98, this may be indicated by 
specifying the corresponding paragraph and the statement ``[Reserved]. 
For guidance see Sec. 86.1313-94''.
    (a) through (b)(1) [Reserved]. For guidance see Sec. 86.1313-94.
    (b)(2) Petroleum fuel for diesel engines meeting the specifications 
in Table N98-2, or substantially equivalent specifications approved by 
the Administrator, shall be used in exhaust emissions testing. The 
grade of petroleum fuel used shall be commercially designated as ``Type 
2-D'' grade diesel fuel except that fuel commercially designated at 
``Type 1-D'' grade diesel fuel may be substituted provided that the 
manufacturer has submitted evidence to the Administrator demonstrating 
to the Administrator's satisfaction that this fuel will be the 
predominant in-use fuel. Such evidence could include such things as 
copies of signed contracts from customers indicating the intent to 
purchase and use ``Type 1-D'' grade diesel fuel as the primary fuel for 
use in the engines or other evidence acceptable to the Administrator.

                                                   Table N98-2                                                  
----------------------------------------------------------------------------------------------------------------
                   Item                                   ASTM                    Type 1-D          Type 2-D    
----------------------------------------------------------------------------------------------------------------
Cetane Number............................  D613                                          40-54             40-48
Cetane Index.............................  D976                                          40-54             40-48
Distillation range:                                                                                             
    IBP  deg.F...........................  D86                                         330-390           340-400
    ( deg.C).............................  .................................     (165.6-198.9)     (171.1-204.4)
    10 percent point,  deg.F.............  D86                                         370-430           400-460
    ( deg.C).............................  .................................     (187.8-221.1)     (204.4-237.8)
    50 percent point,  deg.F.............  D86                                         410-480           470-540
    ( deg.C).............................  .................................       (210-248.9)     (243.3-282.2)
    90 percent point,  deg.F.............  D86                                         460-520           560-630
    ( deg.C).............................  .................................     (237.8-271.1)     (293.3-332.2)
    EP,  deg.F...........................  D86                                         500-560           610-690
    ( deg.C).............................  .................................     (260.0-293.3)     (321.1-365.6)
Gravity,  deg.API........................  D287                                          40-44             32-37
Total Sulfur, percent....................  D2622                                     0.03-0.05         0.03-0.05
Hydrocarbon composition:                                                                                        
    Aromatics, pct.......................  D5186                                         \1\ 8            \1\ 27
    Paraffins, Naphthenes, Olefins.......  D1319                                         (\2\)             (\2\)
Flashpoint,  deg.F.......................  D93                                             120               130
    ( deg.C).............................  .................................            (48.9)            (54.4)
    (minimum)............................  .................................  ................  ................
Viscosity, Centistokes...................  D445                                        1.6-2.0           2.0-3.2
----------------------------------------------------------------------------------------------------------------
\1\ Minimum.                                                                                                    
\2\ Remainder.                                                                                                  

    (b)(3) through (e) [Reserved]. For guidance see Sec. 86.1313-94.
    26. Section 86.1316-90 of subpart N is amended by revising 
paragraph (b)(1) and adding paragraph (f) to read as follows:


Sec. 86.1316-90  Calibrations; frequency and overview.

* * * * *
    (b) * * *
    (1) Calibrate the hydrocarbon analyzer, carbon dioxide analyzer, 
carbon monoxide analyzer, oxides of nitrogen analyzer, methanol 
analyzer and formaldehyde analyzer (certain analyzers may require more 
frequent calibration depending on the equipment and use). New 
calibration curves need not be generated each month if the existing 
curve meets the requirements of Secs. 86.1321 through 86.1324.
* * * * *
    (f) For diesel fuel testing only. The carbon monoxide analyzer 
shall be calibrated at least every two months or after any maintenance 
which could alter calibration.
    27. Section 86.1316-94 of subpart N is amended by revising 
paragraph (b)(1) and adding paragraph (f) to read as follows:


Sec. 86.1316-94  Calibrations; frequency and overview.

* * * * *
    (b) * * *
    (1) Calibrate the hydrocarbon analyzer, carbon dioxide analyzer, 
carbon monoxide analyzer, and oxides of nitrogen analyzer (certain 
analyzers may require more frequent calibration depending on the 
equipment and use).

[[Page 47127]]

New calibration curves need not be generated each month if the existing 
curve meets the requirements of Secs. 86.1321 through 86.1324.
* * * * *
    (f) For diesel fuel testing only. The carbon monoxide analyzer 
shall be calibrated at least every two months or after any maintenance 
which could alter calibration.
    28. Section 86.1319-84 of subpart N is amended by revising 
paragraph (d)(3) and adding paragraph (d)(8) to read as follows:


Sec. 86.1319-84  CVS calibration.

* * * * *
    (d) * * *
    (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)                       .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) of 
this section, 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] TR05SE97.002

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] TR05SE97.003

Where:

Pin-i and Pout-i are the venturi inlet and outlet 
pressures, in absolute 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.
* * * * *
    29. Section 86.1319-90 of subpart N is amended by revising 
paragraph (d)(3) and adding paragraph (d)(8) to read as follows:


Sec. 86.1319-90  CVS calibration.

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

                                                              Calibration Data Measurements                                                             
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Parameter                         Symbol                          Units                             Sensor-readout tolerances            
--------------------------------------------------------------------------------------------------------------------------------------------------------
Barometric pressure (corrected).......  Pb                       in Hg (kPa)                           .01 in Hg (.034 kPa).    
Air temperature, into flowmeter.......  ETI                       deg.F( deg.C)                        0.5  deg.F (0.28  deg.C).
Pressure drop between the inlet and     EDP                      Inches H2O (kPa)                      0.05 in H2O (0.012 kPa). 
 throat of metering venturi.                                                                                                                            
Air flow..............................  Qs                       Ft3/min. (m3/min,)                    .5% of NBS ``true'' value            
CFV inlet depression..................  PPI                      Inches fluid (kPa)                    .13 in fluid (.055 kPa). 
CFV outlet pressure...................  PPO                      Inches Hg (kPa)                       .05 in Hg (.17 kPa).     
Temperature at venturi inlet..........  Tv                        deg.F ( deg.C)                       4.0  deg.F (2.22  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) 
of this section, 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] TR05SE97.004

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] TR05SE97.005

Where:


[[Page 47128]]


Pin-i and Pout-i are the venturi inlet and outlet 
pressures, in absolute 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.
* * * * *
    30. Section 86.1321-90 of subpart N is amended by revising 
paragraphs (a) and (b)(3) to read as follows:


Sec. 86.1321-90  Hydrocarbon analyzer calibration.

* * * * *
    (a) Initial and periodic optimization of detector response. Prior 
to introduction into service and at least annually thereafter, the FID 
hydrocarbon analyzer shall be adjusted for optimum hydrocarbon 
response.
    (1) Follow good engineering practices for initial instrument start-
up and basic operating adjustment using the appropriate fuel (see 
Sec. 86.1314) and zero-grade air.
    (2) Optimize the FID's response on the most common operating range. 
The response is to be optimized with respect to fuel pressure or flow 
while meeting the analyzer response time given in 
Sec. 86.1310(b)(3)(vii)(A) for continuous HC measurement. Efforts shall 
be made to minimize response variations to different hydrocarbon 
species that are expected to be in the exhaust. Good engineering 
judgement is to be used to trade off optimal FID response to propane-
in-air against reductions in relative responses to other hydrocarbons. 
A good example of trading off response on propane for relative 
responses to other hydrocarbon species is given in Society of 
Automotive Engineers (SAE) Paper No. 770141, ``Optimization of Flame 
Ionization Detector for Determination of Hydrocarbon in Diluted 
Automotive Exhausts''; author Glenn D. Reschke. It is also required 
that the response be set to optimum condition with respect to air flow 
and sample flow. Heated Flame Ionization Detectors (HFIDs) must be at 
their specified operating temperature.
    (3) One of the following procedures is to be used for FID or HFID 
optimization:
    (i) Use the procedures outlined in Society of Automotive Engineers 
(SAE) paper No. 770141, ``Optimization of Flame Ionization Detector for 
Determination of Hydrocarbons in Diluted Automobile Exhaust''; author, 
Glenn D. Reschke, as an example.
    (ii) The HFID optimization procedures outlined in 40 CFR part 86, 
subpart D, Sec. 86.331-79(c).
    (iii) Alternative procedures may be used if approved in advance by 
the Administrator.
    (iv) The procedures specified by the manufacturer of the FID or 
HFID.
    (4) After the optimum fuel, air, and sample pressures or flow rates 
have been determined, they shall be recorded for future reference.
    (b) * * *
    (3) Calibrate on each used operating range with a minimum of 6, 
approximately equally spaced, propane-in-air calibration gases (e.g., 
15, 30, 45, 60, 75, and 90 percent of that range). For each range 
calibrated, if the deviation from a least-squares best-fit straight 
line is within 2 percent of the value at each non-zero data 
point and within 0.3 percent of full scale on the zero data 
point, then concentration values may be calculated by using the linear 
calibration equation for that range. If the deviation exceeds these 
limits, then the best-fit non-linear equation which represents the data 
within these limits shall be used to determine concentration values.
* * * * *
    31. Section 86.1321-94 of subpart N is amended by revising 
paragraphs (a) and (b)(3) to read as follows:


Sec. 86.1321-94  Hydrocarbon analyzer calibration.

* * * * *
    (a) Initial and periodic optimization of detector response. Prior 
to introduction into service and at least annually thereafter, the FID 
hydrocarbon analyzer shall be adjusted for optimum hydrocarbon 
response.
    (1) Follow good engineering practices for initial instrument start-
up and basic operating adjustment using the appropriate fuel (see 
Sec. 86.1314) and zero-grade air.
    (2) Optimize the FID's response on the most common operating range. 
The response is to be optimized with respect to fuel pressure or flow 
while meeting the analyzer response time given in 
Sec. 86.1310(b)(3)(vii)(A) for continuous HC measurement. Efforts shall 
be made to minimize response variations to different hydrocarbon 
species that are expected to be in the exhaust. Good engineering 
judgement is to be used to trade off optimal FID response to propane-
in-air against reductions in relative responses to other hydrocarbons. 
A good example of trading off response on propane for relative 
responses to other hydrocarbon species is given in Society of 
Automotive Engineers (SAE) Paper No. 770141, ``Optimization of Flame 
Ionization Detector for Determination of Hydrocarbon in Diluted 
Automotive Exhausts''; author Glenn D. Reschke. It is also required 
that the response be set to optimum condition with respect to air flow 
and sample flow. Heated Flame Ionization Detectors (HFIDs) must be at 
their specified operating temperature.
    (3) One of the following procedures is to be used for FID or HFID 
optimization:
    (i) Use the procedures outlined in Society of Automotive Engineers 
(SAE) paper number 770141, ``Optimization of Flame Ionization Detector 
for Determination of Hydrocarbons in Diluted Automobile Exhaust''; 
author, Glenn D. Reschke, as an example. Available from Society of 
Automotive Engineers International, 400 Commonwealth Dr., Warrendale, 
PA 15096-0001.
    (ii) The procedure listed in subpart D, Sec. 86.331-79(c) of this 
part.
    (iii) The procedures specified by the manufacturer of the FID or 
HFID.
    (iv) Alternative procedures may be used if approved in advance by 
the Administrator.
    (4) After the optimum fuel, air and sample pressures or flow rates 
have been determined, they shall be recorded for future reference.
    (b) * * *
    (3) Calibrate on each used operating range with a minimum of 6, 
approximately equally spaced, propane-in-air calibration gases (e.g., 
15, 30, 45, 60, 75, and 90 percent of that range). For each range 
calibrated, if the deviation from a least-squares best-fit straight 
line is within 2 percent of the value at each non-zero data 
point and within 0.3 percent of full scale on the zero data 
point, then concentration values may be calculated by using the linear 
calibration equation for that range. If the deviation exceeds these 
limits, then the best-fit non-linear equation which represents the data 
within these limits shall be used to determine concentration values.
* * * * *
    32. Section 86.1322-84 of subpart N is amended by revising 
paragraph (b)(3) to read as follows:


Sec. 86.1322-84  Carbon monoxide analyzer calibration.

* * * * *
    (b) * * *
    (3) Calibrate on each used operating range with a minimum of 6, 
approximately equally spaced, carbon monoxide-in-N2 
calibration gases (e.g., 15, 30, 45, 60, 75, and 90 percent of that 
range). For each range calibrated, if the deviation from a least-
squares best-fit straight line is within 2 percent of the

[[Page 47129]]

value at each non-zero data point and within 0.3 percent of 
full scale on the zero data point, then concentration values may be 
calculated by using the linear calibration equation for that range. If 
the deviation exceeds these limits, then the best-fit not-linear 
equation which represents the data within these limits shall be used to 
determine concentration values.
* * * * *
    33. Section 86.1323-84 of subpart N is amended by revising 
paragraph (b)(3) to read as follows:


Sec. 86.1323-84  Oxides of nitrogen analyzer calibration.

* * * * *
    (b) * * *
    (3) Calibrate on each used operating range with a minimum of 6, 
approximately equally spaced, NO-in-N2 calibration gases 
(e.g., 15, 30, 45, 60, 75, and 90 percent of that range). For each 
range calibrated, if the deviation from a least-squares best-fit 
straight line is within 2 percent of the value at each non-
zero data point and within 0.3 percent of full scale on the 
zero data point, then concentration values may be calculated using the 
linear calibration equation for that range. If the deviation exceeds 
these limits, then the best-fit non-linear equation which represents 
the data within these limits shall be used to determine concentration 
values.
* * * * *
    34. Section 86.1324-84 of subpart N is amended by revising 
paragraph (c) to read as follows:


Sec. 86.1324-84  Carbon dioxide analyzer calibration.

* * * * *
    (c) Calibrate on each used operating range with a minimum of 6, 
approximately equally spaced, carbon dioxide-in-N2 
calibration or span gases (e.g., 15, 30, 45, 60, 75, and 90 percent of 
that range). For each range calibrated, if the deviation from a least-
squares best-fit straight line is within 2 percent or less 
of the value at each non-zero data point and within 0.3 
percent of full scale on the zero data point, then concentration values 
may be calculated by using the linear calibration equation for that 
range. If the deviation exceeds these limits, then the best-fit non-
linear equation which represents the data within these limits shall be 
used to determine concentration values.
* * * * *
    35. Section 86.1325-94 of subpart N is amended by revising 
paragraph (c) to read as follows:


Sec. 86.1325-94  Methane analyzer calibration.

* * * * *
    (c) Calibrate on each used operating range with a minimum of 6, 
approximately equally spaced, CH4 in air calibration gases (e.g., 15, 
40, 45, 60, 75, and 90 percent of that range). For each range 
calibrated, if the deviation from a least-squares best-fit straight 
line is within 2 percent of the value at each non-zero data 
point and within 0.3 percent of full scale on the zero data 
point, then concentration values may be calculated by using the linear 
calibration equation for that range. If the deviation exceeds these 
limits, then the best-fit non-linear equation which represents the data 
within these limits shall be used to determine concentration values.
    36. Section 86.1327-90 of subpart N is amended by revising 
paragraphs (b), (f)(1), (f)(2) introductory text and (f)(2)(i) to read 
as follows:


Sec. 86.1327-90  Engine dynamometer test procedures; overview.

* * * * *
    (b) Engine torque and rpm command set points shall be issued at 5 
(10 Hz recommended) Hz or greater during both the cold and hot start 
tests. Feedback engine torque and rpm shall be recorded at least once 
every second during the test.
* * * * *
    (f) * * *
    (1) Gasoline-fueled and methanol-fueled Otto-cycle engines. A 
chassis-type exhaust system shall be used. For all catalyst systems, 
the distance from the exhaust manifold flange(s) to the catalyst shall 
be the same as in the vehicle configuration unless the manufacturer 
provides data showing equivalent performance at another location. 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.
    (2) Petroleum-fueled and methanol-fueled diesel engines. Either a 
chassis-type or a facility-type exhaust system or both systems 
simultaneously may be used. If the engine is equipped with an exhaust 
aftertreatment device, the exhaust pipe must be the same diameter as 
found in-use for at least 4 pipe diameters upstream to the inlet of the 
beginning of the expansion section containing the aftertreatment 
device. The exhaust backpressure or restriction shall follow the same 
criteria as in Sec. 86.1330-90(f) and may be set with a valve (muffler 
omitted). 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.
    (i) The engine exhaust system shall meet the following 
requirements:
    (A) The total length of the tubing from the exit of the engine 
exhaust manifold, turbocharger outlet or aftertreatment device to the 
primary dilution tunnel shall not exceed 32 feet (9.8 m).
    (B) The initial portion of the exhaust system may consist of a 
typical in-use (i.e., length, diameter, material, etc.) chassis-type 
exhaust system.
    (C) The distance from the exhaust manifold flange(s) or 
turbocharger outlet to any exhaust aftertreatment device shall be the 
same as in the vehicle configuration or within the distance 
specifications provided by the manufacturer.
    (D) For engines which are not equipped with exhaust aftertreatment 
devices, all tubing in excess of 12 feet (3.7 m) from the exit of the 
turbocharger or exhaust manifold shall be insulated. For engines 
equipped with exhaust aftertreatment devices, all tubing after the 
aftertreatment device which is in excess of 12 feet (3.7 m) shall be 
insulated.
    (E) If the tubing is required to be insulated, the radial thickness 
of the insulation must be at least 1.0 inch (25 mm). The thermal 
conductivity of the insulating material must have a value no greater 
than 0.75 BTU-in/hr/ft\2\/ deg.F (0.065 W/m-K) measured at 700  deg.F 
(371  deg.C).
    (F) A smoke meter or other instrumentation may be inserted into the 
exhaust system tubing. If this option is exercised in the insulated 
portion of the tubing, then a minimal amount of tubing not to exceed 18 
inches may be left uninsulated. However, no more than 12 feet (3.66 m) 
of tubing can be left uninsulated in total, including the length at the 
smoke meter.
* * * * *
    37. Section 86.1327-94 of subpart N is amended by revising 
paragraphs (b), (f)(1), (f)(2) introductory text and (f)(2)(i) to read 
as follows:


Sec. 86.1327-94  Engine dynamometer test procedures; overview.

* * * * *
    (b) Engine torque and rpm command set points shall be issued at 5 
(10 Hz recommended) Hz or greater during both the cold and hot start 
tests. Feedback engine torque and rpm shall be recorded at least once 
every second during the test.
* * * * *
    (f) * * *
    (1) Otto-cycle engines. A chassis-type exhaust system shall be 
used. For all catalyst systems, the distance from the exhaust manifold 
flange(s) to the catalyst shall be the same as in the

[[Page 47130]]

vehicle configuration unless the manufacturer provides data showing 
equivalent performance at another location. 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.
    (2) Diesel engines. Either a chassis-type or a facility-type 
exhaust system or both systems simultaneously may be used. If the 
engine is equipped with an exhaust aftertreatment device, the exhaust 
pipe must be the same diameter as found in-use for at least 4 pipe 
diameters upstream to the inlet of the beginning of the expansion 
section containing the aftertreatment device. The exhaust backpressure 
or restriction shall follow the same criteria as in Sec. 86.1330-90 (f) 
and may be set with a valve (muffler omitted). 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.
    (i) The engine exhaust system shall meet the following 
requirements:
    (A) The total length of the tubing from the exit of the engine 
exhaust manifold, turbocharger outlet or aftertreatment device to the 
primary dilution tunnel shall not exceed 32 feet (9.8 m).
    (B) The initial portion of the exhaust system may consist of a 
typical in-use (i.e., length, diameter, material, etc.) chassis-type 
exhaust system.
    (C) The distance from the exhaust manifold flange(s) or 
turbocharger outlet to any exhaust aftertreatment device shall be the 
same as in the vehicle configuration or within the distance 
specifications provided by the manufacturer.
    (D) For engines which are not equipped with exhaust aftertreatment 
devices, all tubing in excess of 12 feet (3.7 m) from the exit of the 
turbocharger or exhaust manifold shall be insulated. For engines 
equipped with exhaust aftertreatment devices, all tubing after the 
aftertreatment device which is in excess of 12 feet (3.7 m) shall be 
insulated.
    (E) If the tubing is required to be insulated, the radial thickness 
of the insulation must be at least 1.0 inch (25 mm). The thermal 
conductivity of the insulating material must have a value no greater 
than 0.75 BTU-in/hr/ft2/ deg.F (0.065 W/m-K) measured at 700 
 deg.F (371  deg.C).
    (F) A smoke meter or other instrumentation may be inserted into the 
exhaust system tubing. If this option is exercised in the insulated 
portion of the tubing, then a minimal amount of tubing not to exceed 18 
inches may be left uninsulated. However, no more than 12 feet (3.66 m) 
of tubing can be left uninsulated in total, including the length at the 
smoke meter.
* * * * *
    38. Section 86.1327-96 of Subpart N is amended by revising 
paragraphs (b), (f)(1), (f)(2) introductory text, and (f)(2)(i) to read 
as follows:


Sec. 86.1327-96   Engine dynamometer test procedures; overview.

* * * * *
    (b) Engine torque and rpm command set points shall be issued at 5 
(10 Hz recommended) Hz or greater during both the cold and hot start 
tests. Feedback engine torque and rpm shall be recorded at least once 
every second during the test.
* * * * *
    (f) * * *
    (1) Gasoline-fueled and methanol-fueled Otto-cycle engines. A 
chassis-type exhaust system shall be used. For all catalyst systems, 
the distance from the exhaust manifold flange(s) to the catalyst shall 
be the same as in the vehicle configuration unless the manufacturer 
provides data showing equivalent performance at another location. 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.
    (2) Petroleum-fueled and methanol-fueled diesel engines. Either a 
chassis-type or a facility-type exhaust system or both systems 
simultaneously may be used. If the engine is equipped with an exhaust 
aftertreatment device, the exhaust pipe must be the same diameter as 
found in-use for at least 4 pipe diameters upstream to the inlet of the 
beginning of the expansion section containing the aftertreatment 
device. The exhaust backpressure or restriction shall follow the same 
criteria as in Sec. 86.1330-90(f) and may be set with a valve (muffler 
omitted). 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.
    (i) The engine exhaust systems shall meet the following 
requirements:
    (A) The total length of the tubing from the exit of the engine 
exhaust manifold, turbocharger outlet or aftertreatment device to the 
primary dilution tunnel shall not exceed 32 feet (9.8 m).
    (B) The initial portion of the exhaust system may consist of a 
typical in-use (i.e., length, diameter, material, etc.) chassis-type 
exhaust system.
    (C) The distance from the exhaust manifold flange(s) or 
turbocharger outlet to any exhaust aftertreatment device shall be the 
same as in the vehicle configuration or within the distance 
specifications provided by the manufacturer.
    (D) For engines which are not equipped with exhaust aftertreatment 
devices, all tubing in excess of 12 feet (3.7 m) from the exit of the 
turbocharger or exhaust manifold shall be insulated. For engines 
equipped with exhaust aftertreatment devices, all tubing after the 
aftertreatment device which is in excess of 12 feet (3.7 m) shall be 
insulated.
    (E) If the tubing is required to be insulated, the radial thickness 
of the insulation must be at least 1.0 inch (25 mm). The thermal 
conductivity of the insulating material must have a value no greater 
than 0.75 BTU-in/hr/ft2/ deg.F (0.065 W/m-K) measured at 700 
 deg.F (371  deg.C).
    (F) A smoke meter or other instrumentation may be inserted into the 
exhaust system tubing. If this option is exercised in the insulated 
portion of the tubing, then a minimal amount of tubing not to exceed 18 
inches may be left uninsulated. However, no more than 12 feet (3.66 m) 
of tubing can be left uninsulated in total, including the length at the 
smoke meter.
* * * * *
    39. Section 86.1327-98 is added to subpart N to read as follows:


Sec. 86.1327-98  Engine dynamometer test procedures; overview.

    Section 86.1327-98 includes text that specifies requirements that 
differ from Sec. 86.1327-96. Where a paragraph in Sec. 86.1327-96 is 
identical and applicable to Sec. 86.1327-98, this may be indicated by 
specifying the corresponding paragraph and the statement ``[Reserved]. 
For guidance see Sec. 86.1327-96''.
    (a) through (d)(3) [Reserved]. For guidance see Sec. 86.1327-96.
    (d)(4) Additional accessories (e.g., oil cooler, alternators, air 
compressors, etc.) may be installed or their loading simulated if 
typical of the in-use application. This loading shall be parasitic in 
nature and, if used, shall be applied during all engine testing 
operations, including mapping. The accessory work performed shall not 
be included in the integrated work used in emissions calculations.
    (d)(5) through (f) [Reserved]. For guidance see Sec. 86.1327-96.
    40. Section 86.1330-84 of subpart N is amended by revising 
paragraphs (b)(1), (b)(2), and (f)(1)(i) and adding paragraph (b)(5) to 
read as follows:


Sec. 86.1330-84  Test sequence; general requirements.

* * * * *

[[Page 47131]]

    (b) * * *
    (1) The temperature of the CVS dilution air shall be maintained 
above 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 
throughout the test sequence, except as permitted by Sec. 86.1335-84.
    (2) For engines with auxiliary emission control devices which sense 
or detect ambient air temperature and operate at 68  deg.F or higher, 
the test cell ambient air temperature and the temperature of the engine 
intake air shall be maintained at 77  deg.F 9  deg.F (25 
deg.C 5  deg.C) throughout the test sequence. For engines 
with auxiliary emission control devices which are temperature dependent 
and operate at 68  deg.F or higher, the temperature of the engine 
intake air shall be maintained at 77  deg.F 9  deg.F (25 
deg.C 5  deg.C) throughout the test sequence.
* * * * *
    (5) For engines equipped with an air-to-air intercooler (or any 
other low temperature charge air cooling device) between the 
turbocharger compressor and the intake manifold, the procedure for 
simulating the device in the transient dynamometer test facilities 
shall follow the SAE Recommended Practice J1937, ``Engine Testing with 
Low Temperature Charge Air Cooling System in a Dynamometer Test Cell.''
* * * * *
    (f) Diesel-Fueled Engines only. (1)(i) Air inlet restriction shall 
be set to a value midway between a clean filter and the maximum 
restriction specified by the manufacturer. The exhaust restriction 
normally shall be set at 80 percent of the manufacturer's recommended 
maximum specified exhaust restriction. The manufacturer shall be liable 
for emission compliance from the minimum in-use restrictions to the 
maximum restrictions specified by the manufacturer for that particular 
engine.
* * * * *
    41. Section 86.1330-90 of subpart N is amended by revising 
paragraphs (b)(1), (b)(2), and (f)(1)(i) and adding paragraph (b)(5) to 
read as follows:


Sec. 86.1330-90  Test sequence; general requirements.

* * * * *
    (b) * * *
    (1) The temperature of the CVS dilution air shall be maintained at 
greater than 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 throughout the test sequence, except as permitted by 
Sec. 86.1335-84.
    (2) For engines with auxiliary emission control devices which sense 
or detect ambient air temperature and operate at 68  deg.F or higher, 
the test cell ambient air temperature and the temperature of the engine 
intake air shall be maintained at 77  deg.F 9  deg.F (25 
deg.C 5  deg.C) throughout the test sequence. For engines 
with auxiliary emission control devices which are temperature dependent 
and operate at 68  deg.F or higher, the temperature of the engine 
intake air shall be maintained at 77  deg.F 9  deg.F (25 
deg.C 5  deg.C) throughout the test sequence.
* * * * *
    (5) For engines equipped with an air-to-air intercooler (or any 
other low temperature charge air cooling device) between the 
turbocharger compressor and the intake manifold, the procedure for 
simulating the device in the transient dynamometer test facilities 
shall follow the SAE Recommended Practice J1937, ``Engine Testing with 
Low Temperature Charge Air Cooling System in a Dynamometer Test Cell.''
* * * * *
    (f) Petroleum-fueled and methanol-fueled diesel engines. (1)(i) Air 
inlet restriction shall be set to a value midway between a clean filter 
and the maximum restriction specified by the manufacturer. The exhaust 
restriction normally shall be set at 80 percent of the manufacturer's 
recommended maximum specified exhaust restriction. The manufacturer 
shall be liable for emission compliance from the minimum in-use 
restrictions to the maximum restrictions specified by the manufacturer 
for that particular engine.
* * * * *
    42. Section 86.1333-90 of subpart N is amended by revising 
paragraphs (c), (d) introductory text, (d)(1), (d)(2), (e)(2) and 
removing paragraphs (d)(3) and (d)(4) to read as follows:


Sec. 86.1333-90  Transient test cycle generation.

* * * * *
    (c) Engine speed and torque shall be recorded at least once every 
second during the cold start test and hot start test. The torque and 
rpm feedback signals may be filtered.
    (d) Idle Speed Enhancement Devices (e.g. cold idle, alternator 
idle, etc.). The zero percent speed specified in the engine dynamometer 
schedules (appendix I (f)(1), (f)(2), or (f)(3) to this part) shall be 
superseded by proper operation of the engine's idle speed enhancement 
device.
    (1) During idle speed enhancement device operation, a manual 
transmission engine shall be allowed to idle at whatever speed is 
required to target a feedback torque equal to zero (using, for example, 
clutch disengagement, speed to torque control switching, software 
overrides, etc.) at those points in appendix I (f)(1), (f)(2), or 
(f)(3) to this part where both reference speed and reference torque are 
zero percent values. For each idle segment that is seven seconds or 
longer, the average feedback torque must be within 10 ft-
lbs of zero. To allow for transition, up to the first four seconds may 
be deleted from each idle segment calculation.
    (2) During idle speed enhancement device operation, an automatic 
transmission engine shall be allowed to idle at whatever speed is 
required to target a feedback torque equal to CITT (see (e)(2) of this 
section for definition of CITT) at those points in appendix I (f)(1), 
(f)(2), or (f)(3) to this part where both reference speed and reference 
torque are zero percent values. For each idle segment that is seven 
seconds or longer, the average feedback torque must be within 
10 ft-lbs of CITT. To allow for transition, up to the first 
four seconds may be deleted from each idle segment calculation.
    (e) * * *
    (2) All zero-percent speed, zero-percent torque points (idle 
points) shall be modified to zero percent speed, Curb Idle Transmission 
Torque (CITT), except as permitted in Sec. 86.1337-90(a)(9). Also, all 
points with speed equal to or less than zero percent and torque less 
than CITT shall be modified to CITT. Motoring torque shall remain 
unchanged. In order to provide a smooth torque transition, all 
consecutive torque points that are between 0 and CITT shall be changed 
to CITT if the first of these is preceded or the last of these is 
succeeded by idle points. The manufacturer's specified CITT shall be 
based upon that value observed in typical applications at the mean of 
the manufacturers' specified idle speed range at stabilized temperature 
conditions.
* * * * *
    43. Section 86.1334-84 of subpart N is amended by revising 
paragraph (a)(2) to read as follows:


Sec. 86.1334-84  Pre-test engine and dynamometer preparation.

    (a) * * *
    (2) Following any practice runs or calibration procedures, the 
engine shall be cooled per Sec. 86.1335-90.
    44. Section 86.1335-90 of subpart N is revised to read as follows:


Sec. 86.1335-90  Cool-down procedure.

    (a) This cool-down procedure applies to Otto-cycle and diesel 
engines.
    (b) Engines may be soaked at ambient conditions. No substances or 
fluids may

[[Page 47132]]

be applied to the engine's internal or external surfaces except for 
water and air as prescribed in paragraphs (c) and (d) of this section.
    (c) For water-cooled engines, two types of cooling are permitted:
    (1) Water may be circulated through the engine's water coolant 
system.
    (i) The coolant may be flowed in either direction and at any 
desired flow rate. The thermostat may be removed or blocked open during 
the cool-down but must be restored before the exhaust emissions test 
begins.
    (ii) The temperature of the circulated or injected water shall be 
at least 10  deg.C (50  deg.F). In addition, the temperature of the 
cooling water shall not exceed 30  deg.C (86  deg.F) during the last 30 
minutes of the cool-down.
    (iii) Only water, including the use of a building's standard water 
supply, or the coolant type that is already in the engine (per 
Sec. 86.1327-90(e)) is permitted for cool-down purposes.
    (2) Flows of air may be directed at the exterior of the engine.
    (i) The air shall be directed essentially uniformly over the 
exterior surface of the engine at any desired flow rate.
    (ii) The temperature of the cooling air shall not exceed 86  deg.F 
(30  deg.C) during the last 30 minutes of the cool-down, but may be 
less than 68  deg.F (20  deg.C) at any time.
    (d) For air-cooled engines, only cooling as prescribed in paragraph 
(c)(2) of this section is permitted.
    (e)(1) The cold cycle exhaust emission test may begin after a cool-
down only when the engine oil and water temperatures are stabilized 
between 68  deg.F and 86  deg.F (20  deg.C and 30  deg.C) for a minimum 
of fifteen minutes.
    (i) These temperature measurements are to be made by temperature 
measurement devices immersed in the sump oil and in the thermostat 
housing or cylinder head cooling circuit, the sensor parts of which are 
not in contact with any engine surface.
    (ii) The flow of oil and water shall be shut off during this 
measurement. Air flow, except as necessary to keep the cell temperature 
between 68  deg.F and 86  deg.F (20  deg.C and 30  deg.C), shall be 
shut off. No engine oil change is permitted during the test sequence.
    (2) Direct cooling of engine oil through the use of oil coolers or 
heat exchangers is permitted. The cold cycle emission test may begin 
only when the requirements in paragraph (e)(1)(ii) are met.
    (3) Any other means for the direct cooling of the engine oil must 
be approved in advance by the Administrator.
    (f)(1) The cold cycle exhaust emission test for engines equipped 
with exhaust aftertreatment devices may begin after a cool-down only 
when the aftertreatment device is 77  deg.F 9  deg.F (25 
deg.C 5  deg.C), in addition to the temperature 
restrictions in paragraph (e) of this section. For catalysts, this 
temperature must be measured at the outlet of the catalyst bed.
    (2) Exhaust aftertreatment device cool-down may be accomplished in 
whatever manner and using whatever coolant deemed appropriate by proper 
engineering judgment. The aftertreatment device, engine, and exhaust 
piping configurations shall not be separated, altered, or moved in any 
way during the cool-down.
    (g) For engines with auxiliary emission control devices which are 
temperature dependent, the cold start shall not begin until the 
temperature readings of the auxiliary emission control devices are 
stable at 77  deg.F 9  deg.F (25  deg.C 5 
deg.C).
    (h) At the completion of the cool-down all of the general 
requirements specified in Sec. 86.1330, the oil temperature 
specification set forth in paragraph (e) of this section, and the 
catalyst temperature specifications in paragraph (f) of this section 
must be met before the cold cycle exhaust emission test may begin.
    45. Section 86.1337-90 of subpart N is amended by revising 
paragraphs (a)(9), (a)(10)(i), (a)(10)(ii), (a)(11), (a)(13), (a)(23), 
and (a)(26), and by removing paragraph (a)(10)(iii), to read as 
follows:


Sec. 86.1337-90  Engine dynamometer test run.

    (a) * * *
    (9) As soon as it is determined that the engine is started, start a 
``free idle'' timer. Allow the engine to idle freely with no-load for 
24 1 seconds. This idle period for automatic transmission 
engines may be interpreted as an idle speed in neutral or park. All 
other idle conditions shall be interpreted as an idle speed in gear. It 
is permissible to lug the engine down to curb idle speed during the 
last 8 seconds of the free idle period for the purpose of engaging 
dynamometer control loops.
    (10) * * *
    (i) During diesel particulate sampling it must be demonstrated that 
the ratio of main tunnel flow to particulate sample flow does not 
change by more than 5.0 percent of its set point value 
(except for the first 10 seconds of sampling).

    Note: For double dilution operation, sample flow is the net 
difference between the flow rate through the sample filters and the 
secondary dilution air flow rate.

    (ii) Record the average temperature and pressure at the gas 
meter(s) or flow instrumentation inlet, where needed to calculate flow. 
If the set flow rate cannot be maintained because of high particulate 
loading on the filter, the test shall be terminated. The test shall be 
rerun using a lower flow rate and/or a larger diameter filter.
    (11) Begin the transient engine cycles such that the first non-idle 
record of the cycle occurs at 25 1 seconds. The free idle 
time is included in the 25 1 seconds.
* * * * *
    (13) Immediately after the engine is turned off, turn off the 
engine cooling fan(s) if used, and the CVS blower (or disconnect the 
exhaust system from the CVS). As soon as possible, transfer the ``cold 
start cycle'' exhaust and dilution air bag samples to the analytical 
system and process the samples according to Sec. 86.1340. A stabilized 
reading of the exhaust sample on all analyzers shall be obtained within 
20 minutes of the end of the sample collection phase of the test. 
Analysis of the methanol and formaldehyde samples shall be obtained 
within 24 hours of the end of the sample collection period. For 
petroleum-fueled and methanol-fueled diesel engines, carefully remove 
the filter holder from the sample flow apparatus, and remove each 
particulate sample filter from its holder and invert the secondary 
filter and place it stain side to stain side on top of the primary 
filter. Place the filter pair in a petri dish and cover.
* * * * *
    (23) Allow the engine to idle freely with no-load for 24 
1 seconds. The provisions and interpretations of paragraph 
(a)(9) of this section apply.
* * * * *
    (26) As soon as possible, transfer the ``hot start cycle'' exhaust 
and dilution air bag samples to the analytical system and process the 
samples according to Sec. 86.1340. A stabilized reading of the exhaust 
sample on all analyzers shall be obtained within 20 minutes of the end 
of the sample collection phase of the test. Analyze the methanol and 
formaldehyde samples within 24 hours. (If it is not possible to perform 
analysis within 24 hours, the samples should be stored in a cold 
(approximately 0 deg.C) dark environment until analysis can be 
performed). For petroleum-fueled and methanol-fueled diesel engines, 
carefully remove the assembled filter holder from the sample flow lines 
and remove each particulate sample filter from its holder and invert 
the secondary filter and place it stain side to stain side on top of 
the primary filter. Place the filter pairs in a clean petri dish and

[[Page 47133]]

cover as soon as possible. Within 1 hour after the end of the hot start 
phase of the test, transfer the particulate filters to the weighing 
chamber for post-test conditioning.
* * * * *
    46. Section 86.1337-96 of subpart N is amended by revising 
paragraphs (a)(9), (a)(10)(i), (a)(10)(ii), (a)(11), (a)(13), (a)(23), 
and (a)(26), and by removing paragraph (a)(10)(iii) to read as follows:


Sec. 86.1337-96  Engine dynamometer test run.

    (a) * * *
    (9) As soon as it is determined that the engine is started, start a 
``free idle'' timer. Allow the engine to idle freely with no-load for 
241 seconds. This idle period for automatic transmission 
engines may be interpreted as an idle speed in neutral or park. All 
other idle conditions shall be interpreted as an idle speed in gear. It 
is permissible to lug the engine down to curb idle speed during the 
last 8 seconds of the free idle period for the purpose of engaging 
dynamometer control loops.
    (10) * * *
    (i) During diesel particulate sampling it must be demonstrated that 
the ratio of main tunnel flow to particulate sample flow does not 
change by more than 5.0 percent of its set point value 
(except for the first 10 seconds of sampling). For double dilution 
operation, sample flow is the net difference between the flow rate 
through the sample filters and the secondary dilution air flow rate.
    (ii) Record the average temperature and pressure at the gas 
meter(s) or flow instrumentation inlet, where needed to calculate flow. 
If the set flow rate cannot be maintained because of high particulate 
loading on the filter, the test shall be terminated. The test shall be 
rerun using a lower flow rate and/or a larger diameter filter.
    (11) Begin the transient engine cycles such that the first non-idle 
record of the cycle occurs at 251 seconds. The free idle 
time is included in the 251 seconds.
* * * * *
    (13) Immediately after the engine is turned off, turn off the 
engine cooling fan(s) if used, and the CVS blower (or disconnect the 
exhaust system from the CVS). As soon as possible, transfer the ``cold 
start cycle'' exhaust and dilution air bag samples to the analytical 
system and process the samples according to Sec. 86.1340. A stabilized 
reading of the exhaust sample on all analyzers shall be obtained within 
20 minutes of the end of the sample collection phase of the test. 
Analysis of the methanol and formaldehyde samples shall be obtained 
within 24 hours of the end of the sample collection period. For 
petroleum-fueled and methanol-fueled diesel engines, carefully remove 
the filter holder from the sample flow apparatus, remove each 
particulate sample filter from its holder and invert the secondary 
filter and place it stain side to stain side on top of the primary 
filter. Place the filter pair in a petri dish and cover.
* * * * *
    (23) Allow the engine to idle freely with no-load for 
241 seconds. The provisions and interpretations of 
paragraph (a)(9) of this section apply.
* * * * *
    (26) As soon as possible, transfer the ``hot start cycle'' exhaust 
and dilution air bag samples to the analytical system and process the 
samples according to Sec. 86.1340. A stabilized reading of the exhaust 
sample on all analyzers shall be obtained within 20 minutes of the end 
of the sample collection phase of the test. Analyze the methanol and 
formaldehyde samples within 24 hours. (If it is not possible to perform 
analysis within 24 hours, the samples should be stored in a cold 
(approximately 0  deg.C) dark environment until analysis can be 
performed). For petroleum-fueled and methanol-fueled diesel engines, 
carefully remove the assembled filter holder from the sample flow lines 
and remove each particulate sample filter from its holder and invert 
the secondary filter and place it stain side to stain side on top of 
the primary filter. Place the filter pairs in a clean petri dish and 
cover as soon as possible. Within 1 hour after the end of the hot start 
phase of the test, transfer the particulate filters to the weighing 
chamber for post-test conditioning.
* * * * *
    47. Section 86.1338-84 of subpart N is revised to read as follows:


Sec. 86.1338-84  Emission measurement accuracy.

    (a) Measurement accuracy--Bag sampling. (1) Good engineering 
practice dictates that exhaust emission sample analyzer readings below 
15 percent of full scale chart deflection should generally not be used.
    (2) Some high resolution read-out systems such as computers, data 
loggers, etc., can provide sufficient accuracy and resolution below 15 
percent of full scale. Such systems may be used provided that 
additional calibrations of at least 4 non-zero nominally equally spaced 
points, using good engineering judgement, below 15 percent of full 
scale are made to ensure the accuracy of the calibration curves.
    (3) The following procedure shall be followed:
    (i) Span the analyzer using a calibration gas that meets the 
accuracy requirements of Sec. 86.1314-84(f)(2), is within the operating 
range of the analyzer and at least 90% of full scale.
    (ii) Generate calibration data over the full concentration range at 
a minimum of 6, approximately equally spaced, points (e.g. 15, 30, 45, 
60, 75 and 90 percent of the range of concentrations provided by the 
gas divider). If a gas divider or blender is being used to calibrate 
the analyzer and the requirements of paragraph (a)(2) of this section 
are met, verify that a second calibration gas with a concentration 
between 10 and 20 percent of full scale can be named within 2 percent 
of its certified concentration. If more calibration points are needed 
to meet the requirements of paragraph (a)(2) of this section, continue 
with paragraph (a)(3)(iii) of this section.
    (iii) If a gas divider or blender is being used to calibrate the 
analyzer, input the value of a second calibration gas (a span gas may 
be used for calibrating a CO2 analyzer) having a named 
concentration between 10 and 20 percent of full scale. This gas shall 
be included on the calibration curve. Continue adding calibration 
points by dividing this gas until the requirements of paragraph (a)(2) 
of this section are met.
    (iv) Fit a calibration curve per Secs. 86.1321 through 86.1324 for 
the full scale range of the analyzer using the calibration data 
obtained with both calibration gases.
    (b) Measurement accuracy--Continuous sampling. (1) Analyzers used 
for continuous analysis must be operated such that the measured 
concentration falls between 15 and 100 percent of full scale chart 
deflection. Exceptions to these limits are:
    (i) Analyzer response less than 15 percent or more than 100 percent 
of full scale may be used if automatic range change circuitry is used 
and the limits for range changes are between 15 and 100 percent of full 
scale chart deflection;
    (ii) Analyzer response less than 15 percent of full scale may be 
used if one of the following is true:
    (A) Alternative (a)(2) of this section is used to ensure that the 
accuracy of the calibration curve is maintained below 15 percent; or
    (B) The full scale value of the range is 155 ppm (C) or less.
    (iii) Analyzer response over 100% of full scale may be used if it 
can be shown that readings in this range are accurate.
    (iv) The HC and CO readings are allowed to ``spike'' above full 
scale of the analyzer's maximum operating range for a maximum 
accumulation of 5

[[Page 47134]]

seconds. These analyzer readings shall default to the maximum readable 
value during this time.
    (c) If a gas divider is used, the gas divider shall conform to the 
accuracy requirements specified in Sec. 86.1314-84(g), and shall be 
used according to the procedures contained in (a) and (b) of this 
section.
    48. Section 86.1339-90 of subpart N is revised to read as follows:


Sec. 86.1339-90  Particulate filter handling and weighing.

    (a) At least 1 hour before the test, place a filter pair in a 
closed (to eliminate dust contamination) but unsealed (to permit 
humidity exchange) petri dish and place in a weighing chamber meeting 
the specifications of Sec. 86.1312 for stabilization.
    (b) At the end of the stabilization period, weigh each filter pair 
on a balance having a precision of 20 micrograms and a readability of 
10 micrograms. This reading is the tare weight of the filter pair and 
must be recorded (see Sec. 86.1344(e)(18)).
    (c) The filter pair shall then be stored in a covered petri dish or 
a sealed filter holder, either of which shall remain in the weighing 
chamber until needed for testing.
    (d) If the filter pair is not used within 1 hour of its removal 
from the weighing chamber, it must be re-weighed before use. This limit 
of 1 hour may be replaced by an 8-hour limit if either of the following 
three conditions are met:
    (1) A stabilized filter pair is placed and kept in a sealed filter 
holder assembly with the ends plugged; or
    (2) A stabilized filter pair is placed in a sealed filter holder 
assembly, which is then immediately placed in a sample line through 
which there is no flow; or
    (3) A combination of the conditions specified in paragraphs (d) (1) 
and (2) of this section.
    (e) After the emissions test, remove the filters from the filter 
holder and place them face to face in a covered but unsealed petri 
dish. They must then be conditioned in the weighing chamber for at 
least one hour. The filters are then weighed as a pair. This reading is 
the gross weight of the filters (Pf) and must be recorded (see 
Sec. 86.1344-90(e)(19)).
    (f) The net particulate weight (Pf) on each filter pair is the 
gross weight minus the tare weight. Should the sample on the filters 
(exhaust or background) contact the petri dish or any other surface, 
the test is void and must be rerun.
    (g) Static neutralizers shall be used on petri dishes in accordance 
with good engineering judgement.
    49. Section 86.1341-90 of subpart N is amended by revising 
paragraphs (b), (c) and (d) and removing paragraphs (e) through (h) to 
read as follows:


Sec. 86.1341-90  Test cycle validation criteria.

    (a) * * *
    (b) Brake horsepower-hour calculation. (1) Calculate the brake 
horsepower-hour for each pair of engine feedback speed and torque 
values recorded. Also calculate the reference brake horsepower-hour for 
each pair of engine speed and torque reference values. Calculations 
shall be to five significant digits.
    (2) In integrating the reference and the feedback horsepower-hour, 
all negative torque values shall be set equal to zero and included. If 
integration is performed at a frequency of less than 5 Hz, and if 
during a given time segment, the torque value changes from positive to 
negative or negative to positive, then the negative portion must be 
computed by linear interpolation and set equal to zero and the positive 
portion included. The same methodology shall be used for integrating 
both reference and actual brake horsepower-hour.
    (c) Regression line analysis to calculate validation statistics. 
(1) Linear regressions of feedback value on reference value shall be 
performed for speed, torque and brake horsepower on 1 Hz data after the 
feedback shift has occurred (see paragraph (a) of this section). The 
method of least squares shall be used, with the best fit equation 
having the form:

y=mx+b

Where:

y = The feedback (actual) value of speed (rpm), torque (ft-lbs), or 
brake horsepower.
m = Slope of the regression line.
x = The reference value (speed, torque, or brake horsepower).
b = The y-intercept of the regression line.

    (2) The standard error of estimate (SE) of y on x and the 
coefficient of determination (r2) shall be calculated for 
each regression line.
    (3) For a test to be considered valid, the criteria in Figure N90-
11 must be met for both cold and hot cycles individually. Point 
deletions from the regression analyses are permitted where noted in 
Figure N90-11.

                                                                      Figure N90-11                                                                     
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Speed                                    Torque                          BHP             
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Regression Line Tolerances                                                               
                                                                                                                                                        
                                                   Petroleum-fueled and methanol-fueled diesel engines                                                  
Standard error of estimate (SE) of Y    100 rpm...........................................  13 pct. of power map maximum   8 pct. of power map maximum  
 on X.                                                                                       engine torque                  BHP.                        
Slope of the regression line, m.......  0.970 to 1.030....................................  0.83-1.03 (hot), 0.77-1.03     0.89-1.03 (hot), 0.87-1.03   
                                                                                             (cold)                         (cold).                     
Coefficient of determination, r \2\...  \1\ 0.9700........................................  \1\ 0.8800 (hot), \1\ 0.8500   \1\ 0.9100.                  
                                                                                             (cold).                                                    
Y intercept of the regression line, b.  50 rpm................................  15 ft-lb.........  5.0 BHP.         
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Gasoline-fueled and methanol-fueled Otto-cycle engines                                                 
--------------------------------------------------------------------------------------------------------------------------------------------------------
Standard error of estimate (SE) of Y    100 rpm...........................................  10% (hot), 11% (cold) of       5% (hot), 6% (cold) of power 
 on X.                                                                                       power map max. engine torque.  map maximum BHP.            
Slope of the regression line, m.......  0.980 to 1.020....................................  0.92-1.03 (hot), 0.88-1.03     0.93-1.03 (hot), 0.89-1.03   
                                                                                             (cold)                         (cold).                     
Coefficient of determination, r \2\...  \1\ 0.9700........................................  \1\ 0.9300 (hot), \1\ 0.9000   \1\ 0.9400 (hot), \1\ 0.9300 
                                                                                             (cold)                         (cold).                     
Y intercept of the regression line, b.  25 (hot), 40 (cold).......  4% (hot), 2.0% (hot), 5 (cold) of power map    minus>2.5% (cold) of power  
                                                                                             max. engine torque.            map BHP.                    
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Minimum.                                                                                                                                            


[[Page 47135]]


           Permitted Point Deletions From Regression Analysis           
------------------------------------------------------------------------
                 Condition                      Points to be deleted    
------------------------------------------------------------------------
1. Wide Open Throttle and Torque Feedback   Torque, and/or BHP.         
 < Torque Reference.                                                    
2. Closed Throttle, Not an Idle Point,      Torque, and/or BHP.         
 Torque Feedback > Torque Reference.                                    
3. Closed Throttle, Idle Point, and Torque  Speed, and/or BHP.          
 Feedback = CITT (10 ft-lb).                                
                                                                        
  For the purposes of this discussion:                                  
                                                                        
  An Idle Point is defined as a point having a Normalized Reference     
Torque of 0 and a Normalized Reference Speed of 0 and an engine tested  
as having a manual transmission has a CITT of 0. Point deletion may be  
applied either to the whole or to any part of the cycle.                
------------------------------------------------------------------------

    (4)(i) For petroleum-fueled and methanol-fueled diesel engines, the 
integrated brake horsepower-hour for each cycle (cold and hot start) 
shall be between -15 percent and +5 percent of the integrated brake 
horsepower-hour for the reference cycle, or the test is void.
    (ii) For gasoline-fueled and methanol-fueled Otto-cycle engines, 
the integrated brake horsepower-hour of the feedback cycle shall be 
within 5 percent of the integrated brake horsepower-hour of the 
reference cycle for the cold cycle, or the test is void. The tolerance 
for the hot cycle shall be 4 percent.
    (5) If a dynamometer test run is determined to be statistically or 
experimentally void, corrective action shall be taken. The engine shall 
then be allowed to cool (naturally or forced) and the dynamometer test 
rerun per Sec. 86.1337 or be restarted at Sec. 86.1336-84(e).
    (d) For petroleum-fueled and methanol-fueled diesel engines, all 
reference torque values specified (in paragraph (f)(2) of appendix I to 
this part) as ``closed throttle'' shall be deleted from the calculation 
of cycle torque and power validation statistics.
    50. Section 86.1341-98 is added to subpart N and reads as follows:


Sec. 86.1341-98  Test cycle validation criteria.

    Section 86.1341-98 includes text that specifies requirements that 
differ from Sec. 86.1341-90. Where a paragraph in Sec. 86.1341-90 is 
identical and applicable to Sec. 86.1341-98, this may be indicated by 
specifying the corresponding paragraph and the statement ``[Reserved]. 
For guidance see Sec. 86.1341-90''
    (a) Through (b)(2) [Reserved]. For guidance see Sec. 86.1341-90.
    (b)(3) All feedback torques due to accessory loads, either actual 
or simulated as defined in Sec. 86.1327-90 (d)(4), shall be excluded 
from both cycle validation and the integrated work used for emissions 
calculations.
    (4) For reference idle portions of the cycle where CITT is not 
applied, use measured torque values for cycle validation and the 
reference torque values for calculating the brake horsepower-hour value 
used in the emission calculations. For reference idle portions of the 
cycle where CITT is applied, use measured torque values for cycle 
validation and calculating the brake horsepower-hour value used in the 
emission calculations.
    (c) Through (d) [Reserved]. For guidance see Sec. 86.1341-90.
    51. Section 86.1342-90 of subpart N is amended by removing 
paragraphs (h)(2)(i), (h)(2)(ii), (h)(2)(iii), (h)(2)(iv), (h)(2)(v), 
(h)(2)(vi), (h)(2)(vii) and adding paragraph (i) to read as follows:


Sec. 86.1342-90  Calculations; exhaust emissions.

* * * * *
    (i) For dilute sampling systems which require conversion of as-
measured dry concentrations to wet concentrations, the following 
equation shall be used for any combination of bagged, continuous, or 
fuel mass-approximated sample measurements (except for CO measurements 
made through conditioning columns, as explained in paragraph (d)(3) of 
this section):

Wet concentration = Kw  x  dry concentration.

Where:

    (1)(i) For English units,

Kw = 1-(/200)  x  CO2e(')-((1.608  x  
H)/(7000 + 1.608  x  H))

    See paragraph (d)(1) of this section for  values.
    (ii) For SI units,

Kw = 1-(/200)  x  CO2e(')-((1.608  x  
H)/(1000 + 1.608  x  H))

    See paragraph (d)(1) of this section for  values.

(2) CO2e(') = either CO2e or CO2e' as 
applicable.
(3)(i) H = Absolute humidity of the CVS dilution air, in grains (grams) 
of water per lb (kg) of dry air.

    (ii) For English units,

H ' = [(43.478)Ri'  x  Pd']/
[PB-(Pd'  x  Ri'/100)]

    (iii) For SI units,

H' = [(6.211)Ri'  x  Pd']/
[PB-(Pd'  x  Ri'/100)]
(4) Ri = Relative humidity of the CVS dilution air, in 
percent.
(5) Pd = Saturated vapor pressure, in mm Hg (kPa) at the 
ambient dry bulb temperature of the CVS dilution air.
(6) PB = Barometric pressure, mm Hg (kPa).

    52. Section 86.1342-94 is amended by revising paragraphs (e) 
through (h) and adding paragraph (i) to read as follows:


Sec. 86.1342-94  Calculations; exhaust emissions.

* * * * *
    (e) Through (i) [Reserved]. For guidance see Sec. 86.1342-90.
    53. Section 86.1343-88 is amended by revising the introductory text 
of paragraph (b), redesignating paragraphs (b)(2)(i) through (b)(2)(v) 
as paragraphs (b)(2)(ii) through (b)(2)(vi) respectively and by adding 
a new paragraph (b)(2)(i) to read as follows:


Sec. 86.1343-88  Calculations; particulate exhaust emissions.

* * * * *
    (b) The mass of particulate for the cold-start test and the hot-
start test is determined from the following equation:
* * * * *
    (2)(i)(A) For a CFV-CVS: Vmix = Total dilute exhaust 
volume corrected to standard conditions (293  deg.K (20  deg.C) and 
101.3 kPa (760 mm Hg)), cubic feet per test phase.
    (B) For a PDP-CVS:
    [GRAPHIC] [TIFF OMITTED] TR05SE97.006
    
in SI units,
[GRAPHIC] [TIFF OMITTED] TR05SE97.007

Where:
* * * * *
    \1\ Closed throttle motoring.
---------------------------------------------------------------------------

    \1\  

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

[[Page 47136]]

    53. Appendix I to part 86 is amended by revising the footnote to 
the table in paragraph (f)(2) to read as follows:

Appendix I to Part 86--Urban Dynamometer Schedules

* * * * *
    (f)(1) * * *
    (2) * * *

* * * * *
[FR Doc. 97-23352 Filed 9-4-97; 8:45 am]
BILLING CODE 6560-50-P