# Emission Standards for Clean-Fuel Vehicles and Engines, Requirements for Clean-Fuel Vehicle Conversions, and California Pilot Test Program; Final Rule ENVIRONMENTAL PROTECTION AGENCY

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URL: https://www.frixlaw.com/law-library/documents/fr%3A94-22132

## Record

- **Collection:** Federal Register
- **Document type:** Uncategorized Document
- **Published:** September 30, 1994

## Text

SUMMARY: The 1990 Clean Air Act Amendments require the establishment of
two clean-fuel vehicle programs: a Clean Fuel Fleet Program and a
California Pilot Test Program. Under the Clean Fuel Fleet Program, a
percentage of new vehicles acquired by certain fleet owners located in
covered areas will be required to meet clean-fuel fleet vehicle
emission standards. Fleet owners can comply with this requirement by
purchasing new clean-fuel fleet vehicles, by converting conventional
vehicles to clean-fuel fleet vehicles, or by acquiring ``credits''
pursuant to a credits program. Affected states are required to revise
their State Implementation Plans to implement the fleet program,
including provisions to implement a credit program and exempt clean-
fuel fleet vehicles from certain transportation control measures.
Regulations have already been promulgated for the credit program and
transportation control measures exemptions. Also, definitions of terms
used with the Clean Fuel Fleet program have recently been finalized.
The other Clean Air Act clean-fuel vehicle program is the California
Pilot Test program. This program requires manufacturers to sell light-
duty clean-fuel vehicles in the state of California. EPA has
established a credit program for the California Pilot Test Program in a
separate rulemaking.
This action promulgates the statutory requirements that have not
been implemented to date. These include the emission standards for
light-duty and heavy-duty clean-fuel vehicles, regulations for the
conversion of conventional vehicles to clean-fuel fleet vehicles,
manufacturer California clean-fuel vehicles sales requirements under
the California Pilot Test Program, and a state opt-in program for the
California Pilot Test Program. The part of the conversion provisions
addressing the sales volume limit beyond which special small-volume
manufacturer provisions will not apply, will not become effective
sooner than 60 days after publication and then only if no adverse
comment is received within 30 days of publication. If adverse comment
is received within 30 days of publication, EPA will withdraw this part
of the rule pending a full notice and comment process on this topic.

DATES: This regulation is effective October 31, 1994, except that 40
CFR 88.306-94(b)(3) will become effective on November 29, 1994, unless
notice is received on or before October 31, 1994, that adverse or
critical comments will be submitted. EPA will publish a timely document
in the Federal Register if the effective date is delayed for this
reason. The effective date may also be delayed if the information
collection requirements contained in this section have not been
approved by the Office of Management and Budget. In that case, EPA will
publish a timely document in the Federal Register delaying the
effective date. The incorporation by reference of certain publications
listed in the regulations is approved by the Director of the Federal
Register as of October 31, 1994, except as specified elsewhere in this
DATES section. Sections 40 CFR 88.104-94 (b) and (d), 88.201-94 through
88.206-94, and 88.306-94(b) (1), (2), and (4) are not effective until
the Office of Management and Budget approves the information collection
requirements contained in them. EPA will publish a document in the
Federal Register once the information collection requirements are
approved.

ADDRESSES: Comments on 40 CFR 88.306-94(b)(3) may be submitted to
Docket No. A-92-30 at the following address. Materials relevant to this
proposal have been placed in Docket Nos. A-92-30 (Clean Fuel Fleet
Program) and A-92-69 (California Pilot Test Program) by EPA. The docket
is located at: Air and Radiation Docket and Information Center, Room M-
1500, Waterside Mall, U.S. Environmental Protection Agency, 401 M
Street SW., Washington, DC 20460. These dockets may be inspected
between 8:30 a.m. and noon, and between 1:30 and 3:30 p.m. on weekdays.
EPA may charge a reasonable fee for copying docket materials. In
addition, copies of the Summary and Analysis of Comments document,
which develops certain issues relevant to this final rulemaking, may be
obtained by request from the contact person below. This document
contains the Agency's response to the public comments received in
regard to the two Notices of Proposed Rulemaking (NPRM).
Electronic copies of the preamble, regulations, Regulatory Impact
Analysis, Regulatory Support Document for heavy-duty clean-fuel
vehicles, and the Summary and Analysis of Comments for this rulemaking
are available on the Office of Air Quality Planning and Standards
(OAQPS) Technology Transfer Network Bulletin Board System (TTNBBS).
Instructions for accessing TTNBBS and downloading the above rulemaking
files are described under SUPPLEMENTARY INFORMATION in section I.A.

FOR FURTHER INFORMATION CONTACT: Mr. Bryan Manning, U.S. EPA (SRPB-12),
Regulatory Development and Support Division, 2565 Plymouth Rd, Ann
Arbor, MI 48105. Telephone (313) 741-7832.

SUPPLEMENTARY INFORMATION:

I. Introduction

A. Accessing Electronic Copies of Rulemaking Documents through the
Technology Transfer Network Bulletin Board System (TTNBBS)

TTNBBS can be accessed using a dial-in telephone line (919-541-
5742) and a 1200, 2400, 9600, or 14,400 bps modem. The parity of the
modem should be set to N or none, the data bits to 8, and the stop bits
to 1. When first signing on to the bulletin board, the user will be
required to answer some basic informational questions to register into
the system. After registering, proceed through the following options
from a series of menus:

OMS;
Rulemaking and Reporting;
Alternative Fuels/Fleets;
Clean Fuel Fleets or California Pilot Program.

A list of ``.ZIP'' files will be displayed, all of which relate to
the Clean Fuel Fleet or California Pilot Program rulemakings. The above
five documents for the Emission Standards for Clean-Fuel Vehicles and
Engines, Requirements for Clean-Fuel Vehicle Conversions, and
California Pilot Test Program rulemaking will be listed in the form of
``.ZIP'' files and are identified by the following titles:

``CFF-PRE.ZIP'' (Preamble)
``CFF-REG.ZIP'' (Regulations)
``CFF-COM.ZIP'' (Summary and Analysis of Comments)
``CFF-RIA.ZIP'' (Regulatory Impact Analysis)
``CFF-RSD.ZIP'' (Regulatory Support Document for heavy-duty CFVs)

To download these files, type the instructions below and transfer
according to the appropriate software on your computer: ownload,
rotocol, xamine, ew, ist, elp or to exit: D
filename.ZIP
The user needs to choose a file transfer protocol appropriate for
the user's computer from the options listed on the terminal. The user's
computer is then ready to receive the file by invoking the user's
resident file transfer software. Programs and instructions for de-
archiving compressed files can be found under ystems Utilities from
the top menu, under rchivers/de-archivers.
TTNBBS is available 24 hours a day, 7 days a week except Monday
morning from 8-12 EST, when the system is down for maintenance and
backup. For help in accessing the system, call the systems operator at
919-541-5384 in Research Triangle Park, North Carolina, during normal
business hours EST.

B. Background

The Clean Air Act (CAA) Amendments of 1990 (Public Law 101-549)
added part C to Title II of the CAA entitled, ``Clean Fuel Vehicles''.
Under part C, states are to establish clean fuel fleet programs
(collectively called the Clean Fuel Fleet (or CFF) program) in certain
nonattainment areas and EPA is to establish a clean-fuel vehicle (CFV)
pilot program in the State of California (the California Pilot Test
program or Pilot program).
The purpose of the Clean Fuel Fleet Program is to introduce light-
and heavy-duty CFVs in specified ``covered areas'' with air quality
problems. CAA section 246(a)(2) defines a ``covered area'' for purposes
of the fleet program as an area having a 1980 population of 250,000 or
more that is also (1) a serious, severe, or extreme ozone nonattainment
area (based on 1987-1989 data), or (2) a carbon monoxide (CO)
nonattainment area with a CO design value at or above 16.0 parts per
million (based on 1988-1989 data). Currently, there are 22 such areas
in 19 states (Table 1).

Table 1.--States and Areas Affected by the Clean-Fuel Fleet Program
------------------------------------------------------------------------
Affected area State(s)
------------------------------------------------------------------------
1. Atlanta........................................ Georgia.
2. Baltimore...................................... Maryland.
3. Baton Rouge.................................... Louisiana.
4. Beaumont-Port Arthur........................... Texas.
5. Boston-Lawrence-Worcester (Eastern Massachusetts, New
Massachusetts). Hampshire.
6. Chicago-Gary-Lake County....................... Illinois, Indiana.
7. Denver-Boulder................................. Colorado.
8. El Paso........................................ Texas.
9. Greater Connecticut............................ Connecticut.
10. Houston-Galveston-Brazoria.................... Texas.
11. Los Angeles-South Coast Air Basin............. California.
12. Milwaukee-Racine.............................. Wisconsin.
13. New York-Northern New Jersey-Long Island...... Connecticut, New
Jersey, New York.
14. Philadelphia-Wilmington-Trenton............... Delaware, Maryland,
New Jersey,
Pennsylvania.
15. Providence (All Rhode Island)................. Rhode Island.
16. Sacramento Metro.............................. California.
17. San Diego..................................... California.
18. San Joaquin Valley............................ California.
19. Southeast Desert Modified AQMA................ California.
20. Springfield (Western Massachusetts)........... Massachusetts.
21. Ventura County................................ California.
22. Washington (District of Columbia)............. Maryland, Virginia,
District of
Columbia.
------------------------------------------------------------------------

These states are required to revise their State Implementation
Plans (SIPs) to ensure that ``covered fleet'' owners will include,
through purchase or lease, a minimum percentage of CFVs among the new
vehicles they purchase for their fleets. (A ``covered fleet'' is
defined in CAA section 241 as a fleet of ten or more motor vehicles
which are owned or operated, leased, or otherwise controlled by a
single person.) Both private business and government (federal, state,
and local) fleets are subject to the statute. However, certain fleets
and vehicles are exempt from the regulations, including fleets with
vehicles that cannot be fueled at a central location, vehicles that are
normally garaged at a personal residence, or vehicles that belong to
vehicle classes without applicable CFV standards. (See the Definitions
Rule: 58 FR 64679, December 9, 1993). In their SIP revisions, states
must include provisions to require that CFVs used in the clean fuel
fleet program operate on fuels on which they comply with the CFV
standards.
Covered fleet operaters can also meet the requirements by
converting conventional vehicles to CFVs, or by obtaining credits. CAA
section 246(a)(3) requires that all states containing all or part of an
ozone and/or CO nonattainment area described above that is reclassified
in the future as a serious, severe, or extreme ozone nonattainment
area, or has a CO design value at or above 16.0 parts per million, must
prepare revised SIPs implementing the CFF program within one year of
reclassification.
Three vehicle classes are included in the CFF program: light-duty
vehicles (LDVs) and light-duty trucks (LDTs) up to 8,500 lbs GVWR,\1\
and heavy-duty vehicles (HDVs) between 8,500 lbs and 26,000 lbs
GVWR.\2\ To qualify as a CFV, a vehicle must meet one of three sets of
increasingly stringent standards. These are referred to as low-emission
vehicle (LEV) standards, ultra low-emission vehicle (ULEV) standards,
and zero-emission vehicle (ZEV) standards.
---------------------------------------------------------------------------

\1\Gross Vehicle Weight Rating.
\2\HDVs over 26,000 lbs GVWR are not included in the mandatory
program.
---------------------------------------------------------------------------

CAA section 242(a) requires EPA to promulgate CFV emission
standards for purposes of compliance with the CFF program and the Pilot
program (LEV standards). In addition, section 246(f)(4) requires EPA to
promulgate emission standards for purposes of the CFF program credit
program (ULEV and ZEV standards). Under section 249(d)(3), the CFF
credit program standards will also apply to the Pilot credit program.
Therefore, vehicles that meet ULEV or ZEV standards are eligible for
vehicle purchase credits under the CFF program and for manufacturers'
credits under the Pilot program.
The CAA Amendments of 1990 require EPA to promulgate a Pilot
program for the sale of CFVs in the State of California. Whereas the
CFF program will be run by individual states, the Pilot program is a
federal program that will be administered in California. Manufacturers
with motor vehicle sales in California are required to sell a minimum
number of light-duty CFVs (CFVs up to 8,500 lbs. GVWR) in California on
an annual basis. Manufacturers may meet their share of required sales
by selling the required number of CFVs or by using earned credits or
credits they have acquired from other manufacturers. (EPA established
the credits program in a previous rulemaking (57 FR 60038; December 17,
1992)). To earn credits, a manufacturer may sell more CFVs than
required or sell CFVs which meet stricter exhaust emission standards.
Except for heavy LDTs, for model years 1996 through 2001, the
compliance standards for the Pilot program are known as the TLEV
standards and credits are available for LEV, ULEV and ZEV purchases.
Beginning in 2001, the compliance vehicle shifts to the LEV standards,
and credits are only available for ULEV and ZEV purchases. This
provision commences in the 1998 model year for heavy LDTs.
The CAA also directs EPA to establish a voluntary opt in program
for states that want to adopt the Pilot program. States which contain
all or part of any ozone nonattainment areas classified under subpart D
of Title II as serious, severe, or extreme are eligible to participate.
To do so, states are to revise their state implementation plans (SIPs)
to include incentives for the sale and use of CFVs as well as the
production and distribution of clean alternative fuels. States may not
establish CFV sales or production mandates, however.
The remainder of today's action covers light- and heavy-duty CFV
exhaust emission standards, requirements for vehicle conversions to
CFVs, and the Pilot program, as well as regulatory impacts of the CFF
and Pilot programs. In addition, EPA has included several technical
amendments and clarifications related to the Definitions rule (58 FR
64679) and the rulemaking for the CFF credits program and
transportation control measure exemptions (58 FR 11888; March 1, 1993).

II. Description of Action

A. Clean-Fuel Vehicle Emission Standards

CAA section 242 requires EPA to promulgate regulations setting
emission standards and other requirements for CFVs. For LDVs and LDTs,
EPA is required to adopt the standards set forth in sections 242 and
243 unless it finds that the standards of the California Air Resources
Board LEV program are, in the aggregate, at least as protective of
public health and welfare as the federal standards that would apply to
CFVs. EPA cannot make such a finding at this time so today's
regulations adopt the standards set forth in the CAA.
1. Light-Duty Vehicle and Light-Duty Truck Clean-Fuel Vehicle Standards
a. Requirements of the CAA. Clean Air Act section 241(7) defines a
CFV as a vehicle that meets the emission standards applicable under
part C of Title II of the CAA. As discussed later in this preamble,
CFVs will satisfy the requirements of both the Pilot program and the
CFF program. The CFV emission standards for LDVs and LDTs are set forth
in sections 242 and 243. (Standards for heavy-duty CFVs under section
245 of the Act are discussed in II.A.2 below.) Any LDV, LDT, or HDV
that can operate on only one fuel and that meets these standards will
be classified as a CFV regardless of the fuel that is used to meet the
CFV standards. However, a CFV in the CFF program must operate on clean
alternative fuels, as defined in section 241(2) of the Act, when
operating in the covered area.
Subsections 243(a) through (d) specify LDV and LDT exhaust emission
standards (50K and 100K miles)\3\ for the following pollutants: non-
methane organic gas (NMOG), carbon monoxide (CO), oxides of nitrogen
(NOX), diesel particulate matter (PM) (only for the 100,000 mile
point), and formaldehyde (HCHO). These standards are prescribed in two
phases for LDVs and light LDTs (up to 5,750 pounds loaded vehicle
weight (LVW) and 6,000 pounds GVWR). Phase I applies only to the Pilot
program and takes effect with the 1996 model year (MY), the first year
of required sales under the Pilot program. These statutory Phase I
standards are numerically identical to those which define the
California Transitional Low Emission Vehicle (TLEV).\4\ The Phase I
standards apply to the Pilot program in MYs 1996 through 2001. Phase II
standards are identical to those which define the California Low
Emission Vehicle (LEV).\5\ The Phase II standards apply to the CFF
program in MY 1998 and to the Pilot program beginning in MY 2001. Only
one set of exhaust emission standards applies to heavy LDTs (above
6,000 lbs. GVWR). These standards take effect in MY 1998 and apply to
both the CFF and the Pilot program. Table 2 contains the TLEV and LEV
standards for LDV and LDT CFVs.
---------------------------------------------------------------------------

\3\The intermediate useful life for LDV and LDTs is 50,000 (50K)
miles. The full useful life for such vehicles is 100,000 (100K)
miles.
\4\The California TLEV standards are effective in model years
1994 through 1996.
\5\The California LEV standards are effective in model years
1997 through 2003.
---------------------------------------------------------------------------

CAA part C section 241 specifies that definitions contained in part
A, section 216, shall apply to the CFV programs. The heavy LDT
subcategories (i.e., above 6,000 lbs. GVWR) shown in Table 2 are based
on test weight. CAA section 216(8) defines ``test weight'', or ``TW'',
as the sum of the curb weight and the GVWR divided by two:

TW = (Curb weight + GVWR)/2 = ALVW

This definition was established in 40 CFR 86.129-94 by the federal Tier
1 rulemaking (56 FR 25724; June 5, 1991) and is referred to as
``adjusted loaded vehicle weight'', or ``ALVW''. The Agency chose to
use ALVW, as opposed to TW, to minimize confusion with the term
``equivalent test weight'', which is used interchangeably with ``test
weight'' throughout current EPA motor vehicle regulations and test
procedures. Therefore, ``test weight'' defined in CAA section 216(8) is
referred to as ALVW in this Final Rule, which is consistent with its
definition established in the Tier 1 regulations.

Table 2.-- Phase I and II LDV and LDT Clean Fuel Vehicle Emission
Standards
------------------------------------------------------------------------
Pollutant (grams/mile)
Standards (Effective Dates) --------------------------------------------
NMOG CO NOX HCHO PM\1\
------------------------------------------------------------------------
All LDVs; LDTs 3750 lbs LVW; 6000 lbs GVWR:

Phase I (1996 MY):

50,000 miles........... 0.125 3.4 0.4 0.015 ...
100,000 miles.......... 0.156 4.2 0.6 0.018 0.08

Phase II (1998 MY for CFFP; 2001 MY for Pilot program):

50,000 miles........... 0.075 3.4 0.2 0.015 ...
100,000 miles.......... 0.090 4.2 0.3 0.018 0.08
LDTs >3750 and K5750 lbs LVW; 6000 lbs GVWR:

Phase I (1996 MY):

50,000 miles........... 0.160 4.4 0.7 0.018 ...
100,000 miles.......... 0.200 5.5 0.9 0.023 0.08

Phase II (1998 MY for CFFP; 2001 MY for Pilot program):

50,000 miles........... 0.100 4.4 0.4 0.018 ...
100,000 miles.......... 0.130 5.5 0.5 0.023 0.08

LDTs >6000 lbs GVWR (1998
MY):
3750 lbs ALVW:
50,000 miles........... 0.125 3.4 \2\0.4 0.015 ...
120,000 miles.......... 0.180 5.0 0.6 0.022 0.08
375065750 lbs ALVW:
50,000 miles........... 0.160 4.4 \2\0.7 0.018 ...
120,000 miles.......... 0.230 6.4 1.0 0.027 0.10
57508500 lbs ALVW:\3\
50,000 miles........... 0.195 5.0 \2\1.1 0.022 ...
120,000 miles.......... 0.280 7.3 1.5 0.032 0.12
------------------------------------------------------------------------
\1\Applicable to diesel-fueled vehicles only.
\2\Standards not applicable to diesel-fueled vehicles.
\3\Option of certifying HDEs in vehicles up to 10,000 lbs GVWR using the
LDT standards.

CAA section 242(c) lists the useful life and in-use testing
limitations for purposes of determining in-use compliance with the
standards in section 243. The useful life for CFVs is the same as
adopted in EPA's regulations for 1994 and later model year LDVs and
LDTs, commonly called Tier 1 standards (56 FR 25724, June 5, 1991). For
LDVs and LDTs, the standards in section 243 are established at the
intermediate useful life of five years or 50,000 miles (5/50,000),
whichever occurs first, and a full useful life of 10 years or 100,000
miles (10/100,000), whichever occurs first (see Table 2). With respect
to in-use testing, however, section 242(c) provides that such testing
for these vehicle classes would not be done beyond seven years or
75,000 miles, whichever occurs first. The analogous intermediate and
full useful life levels for heavy LDTs are 5/50,000 and 11/120,000,
respectively (see Table 2). Similarly, section 242(c) provides that the
in-use testing for these vehicles would not be done beyond seven years
or 90,000 miles, whichever occurs first.
While the standards described above apply to single fuel CFVs,
subsection 243(d) also establishes different CFV NMOG standards for
dual and flexible fuel LDVs and LDTs.\6\ These vehicles are to be
certified to two sets of NMOG standards (Table 3). One set contains the
same NMOG levels that apply to single fuel CFVs; dual and flexible fuel
vehicles must meet this standard when operating on the clean
alternative fuel on which they are certified (section 243(d)(2)). The
second set of NMOG standards applies to flexible and dual fuel vehicles
when operated on conventional fuel for which they are certified
(section 243(d)(3)).\7\ This second set of standards is, in effect,
equivalent to the next less stringent set of standards for the
applicable vehicle category and model year. For example, the Phase I
NMOG standard for flexible or dual fuel CFVs using conventional fuel is
equivalent to the Tier I non-methane hydrocarbon (NMHC) emissions
standard.\8\ The Phase II NMOG standard for flexible or dual fuel CFVs
using conventional fuel is equivalent to the Phase I standard for
single fuel CFVs. The NMOG standards for flexible and dual fuel
vehicles are listed in Table 3. Flexible or dual fuel vehicles must
comply with all other CFV exhaust standards shown in Table 2 and with
all other applicable requirements of Title II.
---------------------------------------------------------------------------

\6\Dual fuel vehicle is defined as any motor vehicle or motor
vehicle engine engineered and designed to be operated on two
different fuels, but not on a mixture of the fuels. The term ``bi-
fuel'' is often used for this type of design. Flexible fuel vehicle
is defined as any motor vehicle or motor vehicle engine engineered
and designed to be operated on any mixture of two or more different
fuels. The term ``variable-fuel'' is often used for this type of
design. These definitions are contained in section Sec. 88.102-94 of
the regulatory text.
\7\CAA section 241 requires that dual and flexible fuel vehicles
are to operate on the fuels on which they are certified. As
discussed in the CFF credit program and TCM exemptions rulemaking
(58 FR 11888, March 1, 1993), dual and flexible fuel vehicles shall
operate only on the clean alternative fuel on which they are
certified to the CFV standards when operating in a covered area, as
provided in section 246(a)(2).
\8\NMOG and NMHC emissions are essentially equivalent when the
fuel combusted is conventional gasoline.

Table 3.--NMOG Standards for Flexible- and Dual-Fueled Vehicles
------------------------------------------------------------------------
Standard\1\ (g/mi)
Vehicle subclass -------------------------
50,000mi 100,000mi
------------------------------------------------------------------------
LDVs, LDTs (6000 lbs GVWR):

Beginning MY 1996 for Pilot program:

LDTs (0-3,750 lbs. LVW), LDTs............. 0.125/0.25 0.156/0.31
LDTs (3,751-5,750 lbs. LVW)............... 0.160/0.32 0.200/0.40

Beginning MY 1998 for CFFP; MY 2001 for Pilot program:

LDTs (0-3,750 lbs. LVW), LDVs............. 0.075/0.125 0.090/0.156
LDTs (3,751-5,750 lbs. LVW)............... 0.100/0.160 0.130/0.200
LDTs (>6,000 lbs GVWR):

Beginning MY 1998:

LDTs (0-3,750 lbs. ALVW).................. 0.125/0.25 0.180/0.36
LDTs (3,751-5,750 lbs. ALVW).............. 0.160/0.32 0.230/0.46
LDTs (>5,750 lbs. ALVW)................... 0.195/0.39 0.280/0.56
------------------------------------------------------------------------
\1\The standards are presented for flexible- and dual-fueled CFVs when
operating on clean alternative fuel and conventional fuel in the
format ``x/y'' where x represents the NMOG standard when the vehicle
is operated on a clean alternative fuel and y represents the NMOG
standard when the vehicle is operated on a conventional fuel.

CAA section 246(f)(4) directs EPA to establish additional CFV
standards for ULEVs and ZEVs (discussed earlier). These standards,
shown in Table 4, should be more stringent than the CFV standards in
section 243. Vehicles meeting these more stringent standards are
eligible to earn credits which may be used toward compliance under the
CFF program or the Pilot program, as specified in sections 246(f) and
249(d)(3), respectively. The Act requires EPA to set these more
stringent standards for LDVs and LDTs so that they conform ``as closely
as possible'' to the ULEV and ZEV standards established by California
for vehicles in the same class. The California ULEV and ZEV standards
are described below in section A.1.b. in this preamble.

Table 4.--LDV and LDT Clean Fuel Vehicle ULEV Emission Standards
----------------------------------------------------------------------------------------------------------------
Pollutant (grams/mile)
Vehicle category --------------------------------------------------------
NMOG CO NOX HCHO PM\1\
----------------------------------------------------------------------------------------------------------------
LDVs & LDTs 3750 lbs LVW; 6000
lbs GVWR
50,000 miles....................................... 0.040 1.7 0.2 0.008 0.08
100,000 miles...................................... 0.055 2.1 0.3 .011 0.04
LDTs >3750 and 5750 lbs LVW; 6000
lbs GVWR:
50,000 miles....................................... 0.050 2.2 0.4 0.009 0.08
100,000 miles...................................... 0.070 2.8 0.5 0.013 0.04
LDTs >6000 lbs GVWR (1998 MY):
3750 lbs ALVW:
50,000 miles....................................... 0.075 1.7 0.2 0.008
120,000 miles...................................... 0.107 2.5 \2\0.3 0.012 0.04
37505750 lbs ALVW:
50,000 miles....................................... 0.100 2.2 0.4 0.009
120,000 miles...................................... 0.143 3.2 \2\0.5 0.013 0.05
57508500 lbs ALVW:\3\
50,000 miles....................................... 0.117 2.5 0.6 0.011
120,000 miles...................................... 0.167 3.7 \2\0.8 0.016 0.06
----------------------------------------------------------------------------------------------------------------
\1\Applies to diesel vehicles only.
\2\Does not apply to diesel vehicles.
\3\Option of certifying HDEs in vehicles up to 10,000 lbs GVWR using the LDT standards.

CAA section 242(b) states that CFVs up to 8,500 lbs. GVWR ``shall
comply with all motor vehicle requirements of this title (i.e., on-
board diagnostics, evaporative emissions, etc.) which are applicable to
conventional gasoline-fueled vehicles of the same category and model
year, except as provided in section 244 with respect to administration
and enforcement, and except to the extent that any such requirement is
in conflict with the provisions of'' part C. These include, but are not
limited to, standards for cold temperature CO exhaust emissions (cold
CO), on-board diagnostics (OBD), evaporative emission controls (evap),
and onboard refueling vapor recovery (ORVR). Previous requirements such
as crankcase controls and vehicle labeling also apply.
CAA section 243(e) directs EPA to apply the standards of the
California Air Resources Board (CARB) LEV program in lieu of the
standards otherwise applicable to CFVs under sections 242 and 243 if
the CARB standards are, in the aggregate, at least as protective of
public health and welfare as the federal standards that apply to CFVs.
Section 243(e)(1) addresses the replacement of CAA standards if CARB
promulgates a single set of standards while section 243(e)(2) addresses
the replacement if CARB promulgates multiple sets of standards. CARB's
LEV program contains multiple sets of standards to which vehicles can
certify (i.e., LEV, ULEV, and ZEV); therefore, section 243(e)(2) is the
appropriate language for consideration and is provided below:

Section 243(e)(2): If the State of California promulgates
regulations establishing and implementing several different sets of
standards applicable in California pursuant to a waiver approved
under section 209 to any category of vehicles referred to in
subsection (a), (b), (c), or (d) of this section and each of such
sets of California standards is, in the aggregate, at least as
protective of public health and welfare as the otherwise applicable
standards set forth in section 242 and subsection (a), (b), (c), or
(d) of this section, such standards shall be treated as `qualifying
California standards' for purposes of this paragraph. Where more
than one set of qualifying standards are established and
administered by the State of California, the least stringent set of
qualifying California standards shall apply to the clean-fuel
vehicles concerned in lieu of the standards otherwise applicable to
such vehicles under section 242 and this section.

EPA believes that the required comparison between the federal and
CARB standards is not limited to the CFV exhaust emission standards of
sections 242 and 243 but must also include the other Title II standards
referred to in CAA section 242 (i.e., OBD, evap, etc.) and any
California counterparts. Thus, EPA is required to compare the standards
in CAA sections 242(b) and 243 with the CARB standards to determine
whether the CARB standards should replace the federal standards.
As is discussed below in Section II.c., EPA cannot at this time
make the determination that each set of CARB standards is, in the
aggregate, at least as protective as the federal standards that apply
to CFVs. Therefore, this final rule promulgates the emission standards
and requirements for CFVs found in sections 242 and 243 of the CAA.
EPA's reasoning to support this conclusion is included in Section II.c.
Finally, CAA section 244 provides requirements regarding the
administration and enforcement of CFV exhaust emission standards. In
the event that numerical emission standards for CFVs up to 8,500 lbs.
GVWR are the same under the federal and California LEV program, EPA is
to administer and enforce those standards in the same manner and with
the same flexibility as CARB does under the California LEV program.
This requires utilizing the same interpretations and policy judgments
including, but not limited to, requirements regarding certification,
production-line testing, and in-use compliance. The application of
California's administration and enforcement practices does not depend
on whether EPA replaces federal requirements with California
requirements under section 243(e). If the Administrator determines that
adopting California's administration and enforcement approaches would
not meet the criteria for a waiver under section 209, then federal
administration and enforcement procedures and interpretations would
apply.
b. CARB's Low-Emission Vehicle Standards. Pursuant to CAA section
209, the State of California applied to EPA for a waiver on October 4,
1991 for its ``Low-Emission Vehicle and Clean Fuels Regulations''. EPA
granted the waiver on January 7, 1993 (58 FR 4166, January 13, 1993).
(Although states are generally preempted by CAA section 209 from
adopting their own motor vehicle standards, California may adopt its
own standards provided that EPA waivers the preemption provision of
section 209.)
California's regulations establish four new levels of vehicle
emission standards, termed ``vehicle emission categories'', for LDVs,
LDTs, and medium-duty trucks (MDTs).\9\ These new standards are
effective with 1994 model year vehicles.\10\ The California emission
categories are, in order of increasing stringency: TLEV (Transitional
Low Emission Vehicle); LEV (Low Emission Vehicle); ULEV (Ultra Low
Emission Vehicle); and ZEV (Zero Emission Vehicle). The TLEV exhaust
emission standards for NMOG, CO, NOX, PM, and HCHO are identical
to the federal Phase I CFV standards described above. The LEV exhaust
emission standards are identical to the federal Phase II CFV standards.
The California ULEV and ZEV standards are the same as the federal ULEV
and ZEV categories, established for purposes of the CFF and Pilot
program credit programs. CARB defines a ZEV as:

\9\The medium-duty truck class is a vehicle class unique to CARB
and includes trucks between 6,000 and 14,000 lbs GVWR.
\10\See CARB's Proposed Regulations for Low-Emission Vehicles
and Clean Fuels, Staff Report, available in EPA Air Docket A-91-23.
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* * * any vehicle which is certified * * * to produce zero
emissions of any criteria pollutants under any and all possible
operational modes and conditions. A ZEV may be equipped with a fuel
fired heater provided that the fuel fired heater cannot be operated
at ambient temperatures above 40 degrees Fahrenheit and the heater
is demonstrated to have zero evaporative emissions under any and all
possible operational modes and conditions.\11\
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\11\California Code of Regualtions, Title 13, Definitions
Section, Paragraph 15.
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CARB is allowing the use of intermediate in-use compliance
standards that are intended to facilitate compliance by vehicle
manufacturers. These in-use standards are numerically half way between
the certification standards of the new emission category and the old
emission category (e.g., half way between TLEV and LEV standards).
These intermediate standards will be effective through MY 1995 for
TLEVs and through MY 1998 for LEVs and ULEVs.
c. Comparison of CAA and CARB Requirements. As discussed above, CAA
section 243(e) provides that CARB's standards shall replace the federal
CFV and other motor vehicle standards if the CARB standards are, in the
aggregate, at least as protective of public health and welfare as the
CAA standards. While EPA believes that Congress preferred that the
statutory standards be replaced with the CARB standards, EPA cannot at
this time make the determination that CARB standards are, in the
aggregate, at least as protective as the federal standards. Therefore,
as mentioned earlier, EPA is at this time establishing federal
standards that will apply to CFVs in the CFF and Pilot program.
As stated in the proposal, EPA believes that section 243(e)(2)
requires a separate comparison of federal Phase I and Phase II
standards to CARB standards. For the least stringent set of federal CFV
standards (the Phase I standards), the appropriate comparison is to the
least stringent set of California CFV standards (the TLEV standards).
Similarly, the appropriate comparison for the federal Phase II
standards is with the California LEV standards.
The Phase I standards will apply to the Pilot program in the 1996
MY. The phase II standards will apply to the CFF program in the 1998
MY, and to the Pilot program in the 2001 MY. Therefore, the federal
Phase I standards will not apply to any federal CFV program after MY
2001. For this reason, EPA considers the California LEV standards to be
the least stringent set of qualifying California standards after MY
2001, and currently intends to apply the California LEV standard to the
CFF and Pilot programs at that time if replacement of the federal Phase
II standards is warranted under section 243(e)(2). EPA requested
comment in the proposal on this interpretation of the CAA and no
adverse comments were received.
EPA must also compare CARB standards to the following federal
requirements that apply to CFVs to assess whether ``each of such sets
of California standards is, in the aggregate, at least as protective''
as the federal standards: cold CO emissions, evaporative emissions,
onboard refueling vapor recovery, on-board diagnostics, total
hydrocarbons, and non-methane hydrocarbon standards. These standards
are compared individually below.
i. Cold CO emissions. The currently waived California program does
not have a cold CO standard which corresponds to the federal cold CO
standard. It is not yet possible for EPA to consider CARB's cold CO
standards in its comparison of the respective mobile source programs
since California has not yet requested nor received a waiver.
In vehicles using liquid fuel, the difficult process of vaporizing
cold liquid fuel for combustion contributes significantly to cold start
emissions. Gasoline vehicles are most susceptible to this phenomenon in
cold conditions. On July 17, 1992, EPA promulgated a cold CO standard
(57 FR 31888, 40 CFR 86.201) in order to control CO emissions from
gasoline-powered vehicles when operating in cold temperatures.\12\
These regulations became effective for MY 1994. Although these
regulations cover only gasoline-fueled vehicles, CAA section 242(b)
extends the regulations to all CFVs regardless of fuel type by
requiring that CFVs meet all federal requirements of Title II of the
CAA that apply to gasoline vehicles of the same category and model
year.
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\12\CAA Section 202(j) contains provisions for cold CO
requirements.
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On January 14, 1993, CARB approved a cold CO standard which became
effective in September 1993. CARB's regulations include gasoline-
fueled, LPG, and alcohol-fueled vehicles, but do not cover other fuels.
EPA is not able at this time to consider the CARB cold CO regulations
because CARB has not requested nor received a waiver of federal
preemption for its cold CO requirements.
ii. Evaporative emissions. The currently waived CARB evaporative
emission standards and test procedures are not comparable to the
recently promulgated federal evaporative emission standards and test
procedures. Current federal regulations for evaporative emissions
testing are effective through MY 1995, after which new federal
regulations will be phased in. California has two sets of new
evaporative emissions regulations: one set will be implemented only for
10 percent of California's MY 1995 vehicles and the second set, which
CARB is in the process of finalizing at this time, will be phased in
beginning in MY 1996. Indications are that CARB will seek a waiver for
their 1996 evaporative emission regulations once they are finalized.
EPA cannot yet consider CARB's revised evaporative emission regulations
applicable to the 1995 and later model years because CARB has not yet
received a waiver for them.
iii. Refueling emissions. Based on the currently waived California
program, EPA cannot at this time conclude that CARB's refueling
emission control regulations are as stringent as the federal onboard
refueling vapor recovery (ORVR) standards. The currently waived
California Program does not have a mobile source component which
addresses refueling emissions. Federal Title II standards for ORVR will
be required on certain vehicles beginning in MY 1998 (59 FR 16262;
April 6, 1994).\13\ CARB, which currently requires the use of Stage II
vapor recovery equipment at most service stations in California, has
held two workshops to discuss the proper application of refueling
control (November 2, 1993 and March 15, 1994). CARB considered three
options: adopting the federal ORVR regulations,; adopting a California-
specific ORVR rule, test, or standard; or maintaining that California's
current motor vehicle control program is, in the aggregate, at least as
protective as the federal program notwithstanding the lack of ORVR
controls. In a recent CARB mailout (94-27) dated May 27, 1994, ARB
staff announced their proposal to allow the certification of ORVR-
equipped vehicles for sale in California. However, the ARB staff did
not address the equipped vehicles for sale in California. However, the
ARB staff did not address the specific issue of whether ARB will
require ORVR controls for certification. California's final
determination regarding ORVR control must ultimately be approved by the
Air Resources Board.
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\13\The phase-in schedule requires that ORVR standards apply to
40 percent of each manufacturer's LDV sales volume in MY 1998, 80
percent in 1999, and 100 percent in MY 2000. The same phase-in
schedule applies to LDTs up to 8,500 lbs. GVWR but will not begin
until MY 2001 for LDTs up to 6,000 lbs. GVWR and in MY 2004 for LDTs
between 6,001 and 8,500 lbs. GVWR. The requirements do not apply to
vehicles above 8,500 lbs. GVWR.
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EPA is likely to consider California's lack of an ORVR aspect of
its program in the next section 209 waiver proceeding for CARB
regulations applicable to model years 1998 and later. EPA will likely
decide in that context whether California's motor vehicle program
absent ORVR is at least as protective of California as the federal
program.
iv. Volatile organic compound emissions. EPA and California use
different approaches to regulate emissions of volatile organic
compounds (VOCs) from vehicles. Therefore, EPA believes it is useful to
compare California VOC emission standards to the analogous federal
standards on a fuel-by-fuel basis, as presented below. For gasoline-
and diesel-fueled vehicles, EPA concludes that the CARB VOC emission
standards are individually at least as stringent as the federal
standards. However, EPA cannot make this comparison for gaseous and
alcohol fuels at this time because CARB has not yet finalized RAFs
(reactivity adjustment factors) for these fuels.
v. Fuel-by-fuel comparison. As stated above, EPA and CARB use
different approaches to establish VOC emission standards.
Traditionally, federal organic emissions controls have been based on
total hydrocarbon (THC) emissions where mass of THC emissions is
measured by a flame ionization detector (FID), implicitly assuming that
all hydrocarbon emissions behave similarly with respect to ozone
reactivity and FID response. This approach is not used for methanol-
fueled vehicles because emissions from these vehicles consist primarily
of methanol and formaldehyde, and a FID will only detect about 70 to 80
percent of the methanol and very little of the formaldehyde. For
methanol-fueled vehicles, the methanol and formaldehyde emissions are
sampled separately and measured chromatographically while other
emissions are measured by a FID. The oxygen mass is factored out of the
methanol and formaldehyde emissions resulting in ``equivalent
hydrocarbon emissions'', which are then summed with the other FID-
measured hydrocarbons to yield organic material (or total) hydrocarbon
equivalent (OMHCE or THCE) mass. A third approach involves separately
measuring methane and subtracting it from the THC to result in a non-
methane hydrocarbon (NMHC) mass. For methanol-fueled vehicles, NMHC is
equivalent to OMNMHCE (organic material non-methane hydrocarbon
equivalent) or NMHCE (non-methane hydrocarbon equivalent).
The CAA has established THC and NMHC exhaust emission standards for
conventional light-duty gasoline and diesel vehicles (0.41 g/mile for
THC and 0.25 g/mile for NMHC). EPA has also established OMHCE and
OMNMHCE standards for methanol-fueled vehicles (0.41 and 0.25 g/mile,
respectively), an NMHC standard for CNG-fueled vehicles (0.25 g/mile),
and THC and NMHC standards for LPG-fueled vehicles identical to the
gasoline THC and NMHC standards.\14\
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\14\EPA Gaseous Fuels Rule: ``Standards for Emissions from
Natural Gas-Fueled, and Liquified Petroleum Gas-Fueled Motor
Vehicles and Motor Vehicle Engines and Certification Procedures for
Aftermarket Conversion Hardware.'' (Published in the Federal
Register on September 21, 1994).
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CARB measures VOC emissions as non-methane organic gases (NMOG).
Under this approach, the mass of each organic compound except methane
is measured and adjusted according to its ozone-forming reactivity
relative to gasoline emissions. The sum of these adjusted masses is the
amount of NMOG emitted from the vehicle. An alternative CARB NMOG
method involves measuring the total mass of organic emissions and
multiplying this mass by a single RAF for the particular fuel used. A
RAF is equivalent to the ratio of the ozone-forming potential of
emissions from a given fuel and the ozone-forming potential of
conventional gasoline emissions. CARB determines a RAF for each fuel.
Therefore, the relative stringency of the CARB and EPA standards for
organic emissions should be compared for each fuel individually.

Gasoline and Diesel Fuel

For gasoline- and diesel-fueled vehicles, NMHC and NMOG standards
are equivalent since CARB has established a RAF of 1.0 for these fuels.
In addition, since the methane fraction of the THC emissions from these
vehicles is very low,\15\ and since CARB's TLEV and LEV NMOG standards
(.125 and .075 g/mile, respectively) are well below the federal THC
standard (0.41 g/mile), vehicles designed to meet the CARB NMOG
standard will not exceed the federal THC standard. Thus, for gasoline-
and diesel-fueled vehicles, the CARB NMOG standards are at least as
stringent as the federal THC and NMHC standards.
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\15\U.S. Environmental Protection Agency, Office of Mobile
Sources, ``Specifications for S.A.I. Runs,'' Memorandum from Chris
Lindhjem, Penny Carey, and Joe Somers to the Record, April 24, 1992.
---------------------------------------------------------------------------

CNG Fuel

The equivalency of CARB's NMOG standard with the federal NMHC
standards cannot be strictly determined at this point for natural gas
vehicles since CARB has not finalized a RAF for natural gas.
Indications are that CARB may enact a CNG RAF between 0.5 and 0.6. If
CARB adopts a RAF of 0.5 or more, then EPA expects that the CARB TLEV
NMOG standard of 0.125 grams/mile (representing the least stringent set
of CARB standards) will be at least as stringent as the 0.25 grams/mile
federal NMHC standard. A RAF of 0.3 or more would make the CARB LEV
NMOG standard of 0.075 grams/mile equivalent to the federal NMHC
standard.
CNG vehicles being certified as CFVs for use in the CFF and Pilot
program will not be subject to the federal THC standard, therefore, a
comparison of the relative stringency between the federal THC and the
CARB NMOG standard is not appropriate. In the Pilot program NPRM (58 FR
34727, June 29, 1993), EPA requested comment on the appropriateness of
applying a THC standard to natural gas CFVs even though a THC standard
is not applied to other natural gas vehicles. EPA believes that
requiring CNG vehicles to meet the federal THC standard would exclude
CNG vehicles from participating in the CFF and Pilot programs. CNG
vehicles do produce high methane emissions; however, these emissions
have a very low ozone reactivity and are therefore not a significant
contributor to ozone formation, which is a primary objective of both
programs.\16\ In addition, CNG vehicles typically produce lower NMHC
emissions than gasoline-fueled vehicles. Therefore, although a THC
standard would strictly limit the amount of methane emissions a CNG
vehicle could emit, this result would be contrary to the ozone-
reduction goals of the programs when methane reactivity and lower NMHC
emissions of CNG vehicles relative to gasoline-fueled vehicles are
considered. A further consideration in deciding whether to apply a THC
standard to CNG CFVs was the Agency's desire to maintain consistency
with its Gaseous Fuels rule whenever possible; that rule also does not
apply THC standards to CNG vehicles. Commenters were not supportive of
CNG vehicles, including CFVs, being subject to a THC standard.
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\16\See CAA sections 246, 247, and 248.
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LPG Fuel

CARB has not finalized a RAF for LPG fuel. Therefore, EPA cannot at
this time strictly compare the CARB NMOG standard to the federal NMHC
standard for LPG vehicles. However, as with CNG, if CARB adopts a RAF
of at least 0.5, EPA expects that the CARB TLEV and LEV NMOG standard
will be individually at least as stringent as the federal NMHC
standard.

Alcohol Fuels

CARB has finalized a RAF of 0.41 for M85 vehicles and EPA's
analysis indicates that the CARB NMOG standard is individually as
protective as the federal NMHC equivalent standard for M85 fuel.
However, CARB has not established a RAF for E85 and M100 fuel. EPA thus
cannot determine at this time whether the CARB NMOG standards are
individually as protective of public health and welfare as the federal
NMHC equivalent standards for all alcohol-fueled vehicles.
Regarding THC, methane emissions from alcohol-fueled vehicles, as
with gasoline- and diesel-fueled vehicles, are generally low enough
that vehicles meeting the CARB NMOG standards would also comply with
the federal THC standards. Therefore, EPA concludes that the CARB NMOG
standards are individually at least as stringent as the federal THC
standard.
vi. Onboard diagnostics. The currently waived California onboard
diagnostic I (OBD I) regulation is not comparable to the recently
promulgated federal OBD regulation ( 58 FR 9468, February 19, 1993).
The recently promulgated federal OBD regulation is comparable to the
recently revised California OBD II regulation. In fact, EPA has decided
that vehicles demonstrating compliance with CARB onboard diagnostic
(OBD) regulations will be deemed to satisfy federal OBD requirements
through the 1998 model year. However, EPA cannot properly consider
California's OBD II regulations under section 243(e) of the CAA because
California has not yet received a waiver of federal preemption for
them. Thus, in subsequent model years after 1998, vehicle OBD systems
must comply with the federal OBD requirements.
vii. Summary. While the basic CFV exhaust standards are identical
to CARB standards, EPA is not able to find that each set of currently
waived CARB standards are as protective as the federal standards. By
comparison to the federal program established for CFVs today pursuant
to section 242 and 243, the California program lacks comparable
components for at least the federal cold CO standards, recently
promulgated evaporative emission standards and on-board diagnostics, as
well as mobile source control for vehicle refueling vapor recovery.
Since EPA cannot at this time make the required determination under
section 243(e)(2), EPA is promulgating federal standards and
requirements in this final rule that will apply to CFVs. The CAA
exhaust standards will apply to clean fuel vehicles, and will be
administered and enforced according to CARB practices under CAA section
244, which is discussed later under ``Administration and Enforcement''.
Pursuant to section 242(b), federal requirements for cold CO,
evaporative emissions, refueling emissions, OBD (onboard diagnostics),
NMHC, and, with certain exceptions, THC will also apply to CFVs. As
proposed, EPA is waiving testing requirements for the cold CO standards
for gaseous-fueled, diesel-fueled and electric CFVs when manufacturers
demonstrate compliance with the cold CO standard through engineering
analysis or test data.\17\ EPA does not expect problematic cold
temperature CO emissions from gaseous-fueled CFVs since they do not
generally use fuel enrichment strategies to aid with cold starts.
Because of efficient combustion in diesel-fueled vehicles and the
minimal emissions inherent with electric vehicles, EPA does not expect
problematic cold CO emissions from these vehicles either. Also as
discussed above, EPA will not require CNG vehicles to meet the THC
standard due to the conflict with provisions of part C of the Act and
other factors.
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\17\This provision is similar to the requirements for Otto-cycle
vehicles which must show compliance with a PM standard in the Tier 1
rulemaking (56 FR 25730).
---------------------------------------------------------------------------

In the NPRM, EPA had anticipated that the regulatory processes
underway would allow EPA to conclude at the time of this final rule
that each set of California standards is, in the aggregate, at least as
protective of public health and welfare as the otherwise applicable
standards set forth in section 242 and 243. The Agency still believes
that such a conclusion may be possible in the future. EPA will continue
to monitor developments on these issues and, if changing circumstances
warrant, EPA intends to revisit this rule and propose replacing the
federal CFV standards with CARB standards under section 243(e)(2). In
such a situation, the Agency will supplement the record and provide an
opportunity for comment as appropriate.
d. Credit Generating Standards. As mentioned previously, the CAA
requires EPA to establish standards for Ultra-Low Emission Vehicles
(ULEVs) and Zero Emission Vehicles (ZEVs) which are more stringent than
the standards that otherwise apply to CFVs. Section 246(f)(4) of the
CAA states that, ``[t]he standards established by the Administrator
under this paragraph for vehicles under 8,500 lbs. GVWR or greater
shall conform as closely as possible to standards which are established
by the State of California for ULEV and ZEV vehicles in the same
class''. As proposed, EPA is promulgating the ULEV and ZEV standards
established by CARB in the California LEV program as the federal ULEV
and ZEV standards. Section 249(d)(3) specifies that these and other
requirements established for purposes of the credit program for the
Clean Fuel Fleet program shall also apply for purposes of issuing
credits in the Pilot Program.
A ZEV (e.g., an electric vehicle) is defined as a vehicle that
complies with the applicable ZEV standards (40 CFR 88.101). Like CARB,
EPA will determine compliance with the ZEV standard through engineering
analysis rather than by testing. As per section 244 of the CAA, the
federal ZEV standards will be administered and enforced in accordance
with applicable CARB procedures for LDVs and LDTs.
Consistent with the CARB, EPA is establishing ZEV standards which
require zero emissions of the following pollutants: NMOG, NOx, CO,
particulates, and HCHO. (Emissions from non-fuel sources, like tires,
seats, paint, etc., will likely exist as they do for conventional
vehicles and other CFVs.) Compliance with this requirement may be
assessed through engineering analysis. This analysis will include a
description and analysis of all primary or auxiliary equipment and
engines which concludes that no emissions of the stated pollutants is
possible. The engineering analysis will determine that the vehicle fuel
system(s) does not contain either carbon or nitrogen compounds
(including air) which, when burned, form the above regulated exhaust
emissions. Such criteria will also assure that evaporative emissions
will not occur. Emission testing will not be necessary. When
applicable, compliance testing on ZEVs may be performed according to
the testing requirements of CFR Part 86 and 88 (Federal Test Procedure)
at EPA's discretion. As with other CFVs, ZEVs will be subject to the
standards of part 88 which will be administered per CARB's procedures
for LDVs and LDTs and which are incorporated by reference.
Like CARB, EPA will consider a vehicle with an auxiliary heater to
be a ZEV if the heater will not operate at ambient temperatures above
40 degrees Fahrenheit and the heater's power and/or fuel source does
not have any evaporative emissions in use. Commenters responding to
this issue supported this definition, on which EPA requrested comment
in the NPRM. This auxiliary heater will not be subject to the cold CO
standard (contained in 40 CFR Part 86.201-94) because the cold CO
regulations do not require the testing of heaters. In addition, CARB
has provided a specific exemption for ZEVs from the CARB cold CO
requirements (whether or not the vehicle is equipped with an auxiliary
heater); thus EPA's action on this issue is consistent with CARB's
approach. EPA may reconsider subjecting ZEV auxiliary heaters to the
federal cold CO requirement through regulation if circumstances warrant
in the future. Any vehicle with additional power system(s) or auxiliary
engine(s) that might produce regulated pollutants (e.g., a hybrid
vehicle or electric vehicle with an auxiliary power source to run other
vehicle systems) will be subject to the standards of 40 CFR Part 88
(administered per CARB procedures, which are incorporated by reference)
or future applicable regulations and might not qualify as a ZEV. One
respondent requested that EPA establish ZEV exhaust emission standards
above zero such that hybrid electric vehicles may qualify as ZEVs. EPA
has not promulgated a test procedure for such vehicles and therefore
standards have not been established.
e. Administration and Enforcement Per California Practice. As
proposed in the NPRM, EPA will administer and enforce the numerical CFV
exhaust emission standards in the same manner as does the state of
California. Section 244 of the Act directs EPA to administer and
enforce the numerical CFV emission standards in the same manner as CARB
does for vehicles less than 8,500 lbs. GVWR. Specifically, section 244
states that when the applicable CAA and CARB numerical standards are
the same,

Such standards shall be administered and enforced by the
Administrator (1) in the same manner and with the same flexibility
as the State of California administers and enforces corresponding
standards * * *; and (2) subject to the same requirements, and
utilizing the same interpretations and policy judgments, as are
applicable in the case of such CARB standards, including, but not
limited to, requirements regarding certification, production-line
testing, and in-use compliance.

The application of California administration and enforcement
procedures does not depend on whether EPA has replaced federal CFV
standards with California standards under section 243(e). Section
246(f)(4) provides that the credit generating standards are to be
administered and enforced in the same manner as the other CFV
standards. Therefore, EPA will administer and enforce the ULEV and ZEV
standards in the same manner as does CARB.
Section 244 states that EPA shall use California administration and
enforcement procedures unless EPA determines that doing so will not
meet the criteria for a waiver of preemption under section 209. EPA
believes that the application of current California procedures would
meet the criteria for a section 209 waiver. However, in a letter dated
February 17, 1994, CARB requested that EPA waive preemption under
section 209 for certain proposed amendments to California certification
test procedures. EPA is currently analyzing this waiver request to
determine whether these test procedure amendments meet the criteria for
a waiver under section 209. For example, EPA must determine if the
California enforcement procedures, as amended, are consistent with
section 202(a) of the Act.
Until it has completed its analysis of the waiver request, EPA
cannot present a determination that the amended California regulation,
and thus California administration and enforcement, do not meet the
criteria for a waiver under section 209. Given that section 244 directs
EPA to adopt California's procedures unless it makes such a
determination, EPA believes that it is required to adopt today
California's administration and enforcement procedures. EPA believes
this adoption is in accordance with the plain language of section 244.
If EPA later determines that the California enforcement procedures do
not meet the section 209 waiver criteria, it will propose to amend its
regulation regarding enforcement of CFVs according to California
procedures.
California procedures currently require certification testing of
gasoline vehicles either on California reformulated gasoline or on the
current federal gasoline test fuel called ``indolene.'' EPA believes
that adopting this requirement as a part of adopting California
administration and enforcement procedures will allow manufacturers to
certify vehicles both for California as well as the other 49 states. In
most cases, EPA believes that vehicle designs likely to be certified on
California reformulated gasoline to the CFV standards will be capable
of being certified to those standards on indolene as well with no
technological changes.
It is possible that some manufacturers may wish to certify vehicles
on a gasoline formulation different from either California reformulated
gasoline or indolene. For example, a manufacturer may wish to certify
and market a CFV engine family for use by fleet operators only in areas
where federal reformulated gasoline requirements apply, but where
California reformulated gasoline is unavailable or expensive. A CFV
engine family certified only on California reformulated gasoline would
not be an attractive option to fleet operators in areas covered by
federal reformulated gasoline requirements because the vehicles in that
family will not have been demonstrated to comply with the CFV standards
on federal reformulated gasoline. If certifying that family to the CFV
standards on indolene would require additional emission control
development effort over the California-fuel version, but certifying on
a federal reformulated fuel would not, the manufacturer might prefer to
certify on a fuel representative of federal reformulated gasoline.
Thus, such a manufacturer might choose to market a line of CFVs which
could use the local fuel (reformulated gasoline) instead of only
marketing California-fuel versions. In this kind of situation, then,
allowing manufacturers the option of certifying to the CFV standards on
other gasoline formulations might provide fleets covered by the CFF
program with an additional vehicle choice, one which may help them
comply in a cost-effective manner with the requirement that they
operate their CFVs in covered areas only on fuels on which the vehicles
comply with the CFV standards.
While the California procedures adopted here do not appear to
permit certification on gasoline different from California reformulated
gasoline or indolene, EPA is considering whether it has the authority
to propose and promulgate a provision which would permit manufacturers
to request certification on a different gasoline formulation.
Particularly if interest is shown in such a provision on the part of
fleets, vehicle manufacturers, fuel producers, states, or other
interested parties, EPA may issue a proposed rule to permit
certification on any gasoline formulation.
With respect to the NMOG standard, CAA sections 241(3) and 241(4)
provide definitions for NMOG and base gasoline to be used in
determining reactivity adjustments for alternative fuels. Section
241(4) further provides that EPA is to modify these definitions and the
method used for determining reactivity adjustment factors to conform to
the definitions and method used by CARB, provided CARB's definitions
are, in the aggregate, at least as protective of public health and
welfare as the CAA definitions. CARB's definition of NMOG, contained in
the ``definitions'' section of its LEV program regulations, is
identical to the CAA definition. The CAA section 241(4) specifications
for ``base gasoline'' for the most part fall within the specification
ranges for CARB's ``baseline'', i.e., ``conventional'', gasoline used
by CARB in establishing the RAF for methanol-fueled vehicles.\18\ Thus,
EPA concludes that CARB's regulatory definition of ``conventional
gasoline'' is at least as protective as the CAA definition of base
gasoline for determining RAFs.
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\18\California Exhaust Emission Standards and Test Procedures
for 1988 and Subsequent Model Passenger Cars, Light-Duty Trucks, and
Medium-duty Vehicles, Appendix VIII.
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To ensure that the administration and enforcement of the CFV
exhaust emission standards is undertaken in conformance with section
244, EPA incorporates by reference CARB's test procedures and other
regulatory provisions regarding administration and enforcement. (The
California Regulatory Requirements Applicable to the Clean Fuel Fleet
and California Pilot Programs, April 1, 1994, have been incorporated by
reference in 40 CFR 88.104-94(k)(2).) Any vehicle certified by CARB in
California to the same CFV exhaust emission standards promulgated today
will be considered to satisfy the requirements for certification to the
federal CFV exhaust standards although the vehicle must meet all other
Title II requirements as well as qualify as a CFV. For federal
standards which are not currently identical to CARB requirements (e.g.,
cold CO emissions, evaporative emissions, THC, NMHC), the existing
federal administration and enforcement provisions, including the
applicable test procedures, will apply.
Provisions established in the Motor Vehicle and Engine Compliance
Program Fees rule (57 FR 30044, July 7, 1992) give EPA the authority to
recover all reasonable costs associated with enforcement and compliance
activities performed by EPA. CFVs certified for use in the Pilot
program may be subject to California-only fees if a manufacturer only
intends to sell the CFV in California. However, other CFVs certified
under the same process may be subject to fees applicable for a federal
certificate. This would be the case if such CFVs were sold outside of
California (e.g., CFVs used in the CFF program outside California).
As EPA proposed in the NPRM, vehicles certified as CFVs are to be
labeled according to CARB's revised motor vehicle emission control
label specifications.\19\ These revised labeling requirements include
labeling vehicles to designate that they meet LEV, ULEV or ZEV
standards.
---------------------------------------------------------------------------

\19\Contained in California's proposed LEV program, California
Code of Regulations, Title 13, section 1965.
---------------------------------------------------------------------------

2. Heavy-Duty Clean-Fuel Vehicle Standards
Today's rule requires that engines intended for use in clean-fuel
vehicles greater than 8,500 and up to 26,000 pounds GVWR meet a
combined non-methane hydrocarbon (NMHC) plus NOX emissions
standard of 3.8 grams per brake horsepower hour (g/Bhp-hr). This new
standard applies to all light and medium heavy-duty engines which are
to be certified for inclusion in the Clean Fuel Fleet program,
independent of fuel type. (Also, this standard applies to heavy heavy-
duty engines participating in the Clean Fuel Fleet program for the
purpose of generating credits.) Thus, it applies to vehicles operating
on gasoline, diesel, alcohols, gaseous fuels, electricity, and other
fuels.
Section 246(f)(4) of the CAA requires that credit-generating
standards be promulgated for heavy-duty clean-fuel vehicles, including
standards for heavy-duty ULEVs and ZEVs. The CAA requires these
standards to be ``comparable'', which EPA interprets to mean comparable
to the credit-generating standards established for light-duty vehicles.
a. The Heavy-Duty Clean Fuel Vehicle Low-Emission Vehicle
NMHC+NOX Standard. Section 245 of the CAA sets forth the statutory
framework governing establishment of the heavy-duty clean-fuel vehicle
standards. Section 245(a) sets a combined NMHC+NOX standard of
3.15 g/Bhp-hr for engines intended for use in heavy-duty clean-fuel
vehicles, reflecting a 50 percent reduction from the current combined
HC and NOX standards for heavy-duty diesel engines (HDDE). Section
245(b) permits EPA to set a less stringent standard or standards if EPA
determines that the statutory level of 3.15 g/Bhp-hr is infeasible for
clean diesel-fueled engines. Under this provision, EPA must make a
determination as to the feasibility of this standard for clean diesel-
fueled engine technology, taking into account ``durability, costs, lead
time, safety, and other relevant factors.'' If the Administrator
determines that the standard is not feasible for clean diesel-fueled
engines, EPA may set a less stringent standard so long as it is at
least a 30 percent reduction from the combined NMHC plus NOX
standards for model year 1994 heavy-duty engines. A 30 percent
reduction would be equivalent to a NMHC plus NOX standard of 4.41
g/Bhp-hr.
EPA determines today that a combined NMHC+NOX emission
standard of 3.15 g/Bhp-hr is infeasible for clean diesel-fueled
engines, for the reasons discussed below. Under Section 245(b)(1), EPA
has the authority to establish a less stringent standard. The only
statutory criteria for setting the less stringent standard is the
requirement that the standard require at least a 30 percent reduction
from the combined NMHC+NOX standards for the 1994 model year
heavy-duty engines. Because the same standard that will apply to
diesel-fueled vehicles will also apply to vehicles run on other fuels
(including gasoline), EPA has looked at feasibility for both diesel-
and nondiesel-fueled vehicles. Based on these considerations, EPA has
decided to set the standard at 3.8 g/Bhp-hr.
(i) Establishing the NMHC+NOX Standard. In determining whether
the 3.15 g/Bhp-hr NMHC+NOX standard is feasible for clean diesel-
fueled heavy-duty engines, EPA believes that the CAA does not require a
determination that the standard is feasible for every diesel engine
family, but rather that it is feasible for at least enough diesel
engine families such that fleet operators have enough choice to meet
their requirements under the Clean Fuel Fleet Program. The clean-fuel
vehicle standard is not a mandatory national standard for all heavy-
duty vehicles manufactured, but instead applies to vehicles that fleet
owners in certain areas must buy as a certain percentage of their
vehicle purchases beginning in model year 1998.
In the NPRM, EPA proposed a level of 3.5 g/Bhp-hr NMHC+NOX
based on concerns about technology, cost, leadtime, and durability for
diesel engines as prescribed in section 245 (b) of the CAA. Based on
the comments submitted to EPA and further analysis by the Agency, EPA
believes that achieving HDDE emission levels below about 3.5 g/Bhp-hr
NMHC+NOX would be technically difficult and costly to
manufacturers and would not be achievable for an adequate number of
light and medium heavy-duty diesel engine families by 1998. In their
comments, engine manufacturers argued that the 3.15 g/Bhp-hr level, as
well as the proposed 3.5 g/Bhp-hr level, would not be technologically
and economically feasible for diesel-fueled engines. The Natural Gas
Vehicle Coalition (NGVC) argued that the 3.15 g/Bhp-hr level would be
feasible for diesel-fueled engines, based largely on a final report by
Acurex under contract with CARB, entitled ``Technical Feasibility
Reducing NOX and Particulate Emissions from Heavy-Duty
Engines.''\20\ As the analysis summarized below demonstrates, EPA
agrees in part with each set of comments, but reaches a conclusion
different from both.
---------------------------------------------------------------------------

\20\Acurex Environmental Project Under Contract with California
Air Resources Board, Final Report, ``Technical Feasibility of
Reducing NOX and Particulate Emissions From Heavy-Duty
Engines,'' Acurex Environmental Project 8450, Contract No. A132-085,
April 30, 1993 (found in the docket for this rulemaking).
---------------------------------------------------------------------------

As a part of its assessment of the potential HDDE emission control
technology, EPA studied the Acurex report in depth. Like the Regulatory
Support Document associated with this rule,\21\ this report concludes
that to achieve a NOX-emission level of 2.5 g/Bhp-hr by 2000
(NOX levels needed to meet a 3.15 g/Bhp-hr NMHC+NOX
standard),\22\ diesel-fueled engines would need to be equipped with
advanced catalytic trap or EGR (exhaust gas recirculation)
technologies. In addition, the 2.5 g/Bhp-hr level would also require
the use of a combination of some or all of the following emission
control approaches for diesel-fueled engines: very high pressure fuel
injection, variable geometry turbocharging, air-to-air aftercooling,
optimized combustion, electronic unit injections with minimized sac
volumes, optimized fuel injection nozzles, rate shaping, exhaust gas
recirculation and sophisticated electronic control of all engine
systems. Most of the devices described in the Acurex report are in
relatively early stages of development and would require extensive
changes in heavy-duty diesel-powered engines compared to today's
designs. Acurex projects that achieving this level would be possible,
but it would result in a 5 percent fuel economy penalty and a doubling
of the engine price of a 1994 diesel-fueled engine. Based on reasons
discussed throughout this section, EPA is very doubtful that this
standard could be met in a cost-effective manner in time for the
production of an adequate number of 1998 model year engine families.
However, Acurex has projected that a 3.0 g/Bhp-hr NOX-emission
level (approximately equivalent to a 3.5 g/Bhp-hr NMHC+NOX level)
is achievable for diesel-fueled engines by 1999 with the addition of
EGR and oxidation catalyst technology without major new costs or fuel
economy penalties.
---------------------------------------------------------------------------

\21\U.S. Environmental Protection Agency, Office of Mobile
Sources, ``Regulatory Support Document: Emissions Standards for
Heavy-Duty Fleets,'' June 1994 (found in the docket for this
rulemaking).
\22\Current certification data indicate that generally all
diesel engine families have HC certification levels less than 0.5 g/
Bhp-hr, so most reductions would have to be achieved in NOX
emissions. Thus, achieving a 3.15 g/Bhp-hr NMHC+NOX standard
would essentially require NOX-certification levels on the order
of 2.5 to 2.7 g/Bhp-hr.
---------------------------------------------------------------------------

Also, the NGVC argued that no technological breakthroughs are
required to meet the 3.15 standard since each one of these technologies
is already in use in one or more commercial diesel engine families to
meet the 1994 and 1998 standards. They also state that all that would
be required to meet the 3.15 standard would be the addition of EGR and
possibly a particulate trap. Although it is true that some versions of
the necessary technologies are in use today, EPA believes, as stated
above, that the additional development effort needed to reach very low
emission levels would be very costly and would likely limit or
eliminate the availability of heavy-duty diesel engines for the
program.
Furthermore, a review of the 1993 HDE federal certification results
clarifies the magnitude of the developmental task for manufacturers to
achieve extremely low- emission levels, especially for diesels. The
data, which represents engines tested on federal certification fuel,
indicates that no current gasoline or diesel HDE family meets or is
close to the 3.15 g/Bhp-hr standard on federal certification fuel (for
diesel and gasoline engines NMHC and HC are roughly equivalent). Of the
9 gasoline HDE families certified in 1993, three are within one g/Bhp-
hr of the standard (see Figure 1). Based on the aftertreatment control
technology used by and available for gasoline engines, EPA believes
that 3.15 g/Bhp-hr level would be within reach for a number of these
families. For diesel engines, however, the 1993 heavy-duty engine
federal certification results presented in Figure 1 indicate that
achieving the 3.15 g/Bhp-hr standard on federal diesel fuel would be
extremely problematic for the majority of engine families by 1998.
However, five of the 37 diesel engine families certified in 1993 are
within one g/Bhp-hr of the 3.5 g/Bhp-hr NMHC+NOX level (equivalent
to NOX-certification level of 3.0 g/Bhp-hr), indicating that a
standard in this range would more likely be achieved by a variety of
diesel engines on federal certification fuel than would the 3.15 level.
Only one of 37 diesel engine families certified in 1993 is within one
g/Bhp-hr of the 3.15 level; most have combined HC and NOX
certification levels of 5.5 g/Bhp-hr or less.

BILLING CODE 6560-50-P

TR30SE94.000

BILLING CODE 6560-50-C
There are two existing sets of regulations that will drive heavy-
duty engine technology towards low NMHC+NOX levels: the federal
1998 4.0 g/Bhp-hr NOX standard, and the California Air Resources
Board (CARB) LEV standard for diesel engines and incomplete medium-duty
vehicles of 3.5 g/Bhp-hr NMHC+NOX. EPA received many comments in
Docket A-91-28 stating that the 4.0 g/Bhp-hr NOX standard for all
1998 and later HDEs, which is one g/Bhp-hr lower than the existing
standard, is feasible for diesel engines. Development of the technology
necessary to comply with the 4.0 g/Bhp-hr NOX standard will make
it more likely that a significant number of light and medium diesel HDE
families will be able to reach emission levels slightly below 4.0 g/
Bhp-hr NOX on federal diesel fuel in the future, but it is
unlikely that this federal standard will force the development of
technologies needed to achieve a 3.15 g/Bhp-hr NMHC+NOX standard
on such fuel (i.e., NOX levels of 3.0 g/Bhp-hr or less) since
there is no federal requirement to reach lower levels.
CARB's 3.5 g/Bhp-hr NMHC+NOx standard is the only other
impetus driving technology to achieve emission levels significantly
below the 4.0 g/Bhp-hr NOx standard. Engine manufacturers have
stated that the CARB 1998 3.5 g/Bhp-hr NMHC+NOx standard for
incomplete medium-duty vehicles and diesel engines is feasible, and EPA
agrees with CARB's expectation that manufacturers will market a range
of LEV diesel HDEs in California which will meet the California
standard. However, as with the federal 4.0 g/Bhp-hr NOx standard,
it is unlikely the current California standard will prompt the
additional technology development needed to reach a 3.15 g/Bhp-hr
NMHC+NOx level since there is no requirement to reach levels below
3.5 g/Bhp-hr NMHC+NOx. This is especially true for engines
intended for vehicles between 14,000 and 26,000 pounds GVWR, which are
covered by the Clean Fuel Fleet Program but not the current CARB LEV
program.
EPA believes it is appropriate to look at the demand that will be
created for heavy-duty CFVs as a relevant factor when determining
whether a particular combined NMHC+NOx standard for diesel-fueled
vehicles is technologically feasible under section 245(b)(1). For the
reasons discussed above, EPA believes that achieving a level of 3.15 g/
Bhp-hr NMHC+NOx for even a small selection of HDDEs by 1998 will
be a very difficult task. Manufacturers will need to invest
significantly in research and accelerated technology development, and
any engines which reach production would be more costly (in terms of
both engine price increase and fuel economy penalty, as discussed
above), especially based on the relatively small demand that will be
created by the Clean Fuel Fleet Program. In the absence of mandated
production, EPA believes that a technological effort of this magnitude
is likely to be undertaken by engine manufacturers only under
circumstances of a certain, substantial market.
The CFF program contains no authority for a production mandate.
Thus, the size and certainty of the market is central to whether diesel
engines will be developed to meet the requirements of heavy-duty fleets
covered by the fleet program. However, only a small number of vehicles
will be needed by fleets for their fleet program purchase requirements.
For example, during each year of the fleet program EPA estimates that a
maximum of only about 2 percent (10,000) of total nationwide new heavy-
duty diesel vehicles will be purchased by fleet operators to meet the
Clean Fuel Fleet Program requirements.\23\ This projected market
decreases by about 25 percent if California opts out of the Clean Fuel
Fleet Program; other potential opt outs by additional states may reduce
the market to under one percent of nationwide heavy-duty diesel engine
sales (or under about 5000 vehicles). By comparison, based on the
implementation schedule of CARB's LEV program, the annual market
(30,000) for vehicles required to meet CARB's LEV standard for diesel
engines and incomplete medium duty-vehicles of 3.5 g/Bhp-hr
NMHC+NOx is approximately three to six times as large as the
potential federal clean diesel-fueled market.\24\ CARB's program
incorporates a phased-in percentage sales mandate for this larger
number of vehicles.
---------------------------------------------------------------------------

\23\U.S. Environmental Protection Agency, Office of Mobile
Sources, ``Estimated Number of Fleet Vehicles Affected by the Clean
Fuel Fleet Program,'' Memorandum from Sheri Dunatchik to Docket A-
91-25, June 11, 1991.
\24\Heavy-duty vehicle population projections for the California
LEV program are based on the following: (1) light heavy-duty
production reports submitted to the U.S. Environmental Protection
Agency for model year 1991 and (2) New Truck Registrations by
Manufacturer and State data from the ``AAMA Facts and Figures 1993''
(page 27) that shows California truck sales to be 10 percent of
nationwide truck sales.
---------------------------------------------------------------------------

EPA is concerned that a market of the size represented by the CFF
program will not be seen as sufficient for engine manufacturers to
justify the major voluntary technological development efforts necessary
to reach a 3.15 g/Bhp-hr standard. Even if some manufacturers do launch
such an effort, the likely higher cost and possible fuel economy
penalty may make it much more difficult for diesel engine producers to
compete for sales with gasoline or alternative fueled engine options
which may be available. Since developing and producing vehicles for the
fleet program is, by statute, voluntary, the Agency believes that it is
very possible that, with a very low emission standard, no diesels will
be produced for the clean fuel fleet program. The Act is clear in its
intention that EPA may design the fleet program such that clean diesel
vehicles can participate. EPA thus concludes that a standard of 3.15 g/
Bhp-hr is not feasible for heavy-duty diesel-fueled CFVs taking into
account costs, lead time, durability, and other relevant factors, and
should not be promulgated at this time.
EPA reserves the right to reconsider through rulemaking the 3.15 g/
Bhp-hr NMHC+NOx standard at a later time if diesel NOx
control technology and the HD clean-fuel engine market develop to a
point which would make this level feasible for heavy-duty diesel-fueled
CFVs. Such a reconsideration may be prompted by developments in the
ongoing CARB HD LEV program now under consideration.
ii. NMHC+NOx LEV standard. EPA is adopting an approach for the
heavy-duty clean fuel vehicle engine standard that is very similar to
the proposed approach. The intent of this approach is to implement a
challenging standard in a way that harmonizes as completely as possible
the federal standard with CARB's NMHC+NOx LEV standard for diesel
engines and incomplete medium-duty vehicles. The Agency believes that
the effect of this harmonization is to make the overall national market
for clean HDDs significantly larger than it would be with either
program alone and will thus assure that clean diesels will in fact be
produced by 1998 for the clean fuel fleet program.
To meet these objectives, EPA is promulgating a combined
NMHC+NOx clean-fuel engine emission standard of 3.8 g/Bhp-hr for
heavy-duty engines certified on federal diesel certification fuel.
Manufacturers may also certify heavy-duty engines to a standard of 3.5
g/Bhp-hr on California diesel certification fuel, which for a given
engine is approximately equal in stringency to the 3.8 g/Bhp-hr
standard using federal diesel certification fuel, as described below.
The level of stringency represented by these standards should be
achievable for at least several diesel engines with fairly
straightforward technological improvements and without a serious fuel
economy penalty. EPA intends for this approach to assure that the same
engines that are developed and produced for the California LEV program
will also be acceptable to fulfill the requirements of the Clean Fuel
Fleet Program. These vehicles and engines would, as specified by
section 242(b) of the Act, also be required to meet all other
applicable emission standards and requirements of 40 CFR Part 86 (such
as standards for CO, particulates, smoke and evaporative emissions, as
applicable).
As discussed in the NPRM, EPA recognizes that differences between
California and federal certification and in-use diesel fuels may cause
a difference in emission rates. CARB limits the aromatics content of
the test fuel to a maximum of ten percent, while federal test fuel may
contain as much as 35 percent aromatics. There is evidence to suggest
that the use of federal test fuel can result in higher NMHC+NOX
emissions than the use of CARB fuel in the same engine. Apparently,
this occurs because the higher aromatic content of the fuel reduces its
cetane rating and thus combustion is slightly less enhanced. Data
reported in the NPRM for a 1991 prototype DDC Series 60 heavy heavy-
duty engine showed this difference to be in the range of 0.3 g/Bhp-hr
offset.\25\
---------------------------------------------------------------------------

\25\``Effects of Fuel Aromatics, Cetane Number, and Cetane
Improver on Emissions from a 1991 Prototype Heavy-Duty Diesel
Engine,'' T. Ullman, R. Mason, and D. Montalvo, Southwest Research
Institute, SAE Paper 902171., U.S. Environmental Protection Agency,
Office of Mobile Sources, ``Effect of Test Fuel Differences on
NMHC+NOX Emissions,'' Memorandum from Michael Samulski to the
docket of this rulemaking, February 23, 1993.
---------------------------------------------------------------------------

In addition to the analysis of the 1991 prototype heavy-duty diesel
engine referenced in the NPRM, EPA has used a similar analysis to
examine diesel fuel effects based on data presented in a study
performed on a 1993 prototype Navistar Diesel DTA 466 medium heavy-duty
engine.\26\ As had been done in the earlier analysis, EPA compared
federal and California diesel fuels on the basis of aromatic percent
and cetane number. EPA used the specified aromatic levels of 10 percent
for California test fuel and 35 percent for federal test fuel and
natural cetane numbers of 50 and 46 for typical California and federal
certification fuels, respectively.\27\ An API gravity number typical of
both test fuels of 36 degrees was used. The following regression
equations were developed in the study conducted on the 1993 engine for
total hydrocarbon (THC) and NOX:
---------------------------------------------------------------------------

\26\Diesel Fuel Property Effects on Exhaust Emissions from a
Heavy Duty Diesel Engine that Meets the 1994 Emissions Requirements,
``C. McCarthy, Amoco Oil Co., W. Slodowske, E. Sienicke, and R.
Jass, Navistar International Transportation Corp., SAE Paper 922267.
\27\The cetane numbers used in the EPA analysis on the 1993
heavy-duty engine were based on the following: (1) ``Development of
the First CARB certified California Alternative Diesel Fuel'', M.
Nikanjam, SAE Paper 930728, (2) Section 2282, Title 13, California
Code of Regulations procedure for certifying diesel fuel
formulations resulting in equivalent emissions reductions and (3)
Cummins Engine Company and Caterpiller diesel fuel formulations for
federal diesel fuel. These cetane numbers are natural cetane numbers
(without cetane improver).

THC [g/Bhp-hr] = 0.819 - 0.01942 * (Natural Cetane) + 0.01159 *
(API)
NOX [g/Bhp-hr] = 6.593 + 0.01183 * (SFC Aromatics %) - 0.02497
* (Natural Cetane) - 0.02365 (API)

Substituting the values selected above for percent aromatics and
cetane numbers into these equations, the Agency calculated a THC +
NOX offset of about 9.7 percent. Applying this percent offset to
the 3.5 g/Bhp-hr standard for CARB diesel fuel, the Agency analysis
calculated that the offset would be about 0.34 g/Bhp-hr THC + NOX.
(This analysis assumed that the offset would apply equally whether THC
or NMHC was being considered; the Agency has no data to indicate that
the small methane emissions component in diesel emissions would affect
the relative behavior of the engine on the two fuels).
Thus, the Agency concludes that diesel engines certified to a 3.5
g/Bhp-hr level on California diesel fuel would for typical engines,
result in emissions of approximately 3.8 g/Bhp-hr for the same engines
operated on federal diesel fuel, confirming the estimate made in the
NPRM. In their comments engine manufacturers quoted the same data that
EPA has used for the 1991 and 1993 prototype diesel engines, but used
different assumptions for the cetane number for in-use diesel fuel.
Also, the industry analysis did not adjust the offset proportionally to
account for the much lower emissions of CFVs as compared to the current
engine which generated the test data. In their comments, they concluded
that the offset between federal certification fuel and California
certification fuel may be more in the range of 0.55-0.66 g/Bhp-hr. EPA
has examined the assumptions used in the industry analysis and
concluded that the EPA analysis is a more appropriate approach for
determining the expected emissions offset. While this conclusion is
based on data from a single engine, the 1993 engine is of the
appropriate size (medium heavy-duty) from which to draw a conclusion
for this program and the study was done on a meaningful array of diesel
test fuels. It is likely that if similar data were collected on other
engines, somewhat different values for the CARB/federal fuel offset
might be observed. Until such a time when additional data becomes
available, EPA will assume that offsets for other heavy-duty diesel
engines would range on either side of the 0.34 g/bhp-hr level EPA has
developed for the 1993 engine. Thus, the Agency believes that its
analysis reasonably accounts for potential fuel variability and that
the 0.34 g/Bhp-hr value represents a reasonable estimate for the
average emissions offset between federal certification fuel and
California certification fuel. If a reduction catalyst is used as a
means to reduce NOX levels, concerns over fuel variability
diminish significantly. The CARB/federal fuel offset would tend to be
less because the reduction catalyst would reduce emissions
proportionally for both fuels. While the use of reduction catalysts may
not be universal, EPA expects that some light/medium heavy-duty engine
families will use reduction catalyst technology to meet the NOX
target level. Additional data and analysis supporting the above
conclusion of the offset between federal and California diesel fuel can
be found in the Summary and Analysis of Comments document for this
rulemaking.
Based on its analysis of the emissions offset above, EPA has set
the emission standard for HDD CFVs certified on federal diesel fuel at
3.8 g/Bhp-hr NMHC + NOX. This standard is consistent with EPA's
intent that the heavy-duty clean-fuel vehicle standards be of as close
to equivalent stringency as possible to the CARB LEV standard for
similar vehicles to assure the production of an adequate number of
diesel engine models for the clean fuel fleet program. Further, because
the Agency is reasonably confident that in-use emissions of a engine
certified at 3.5 g/Bhp-hr on California fuel will emit in the range of
3.8 g/Bhp-hr on federal fuel, EPA will grant a federal certificate of
conformity to a manufacturer which demonstrates compliance with the 3.5
g/Bhp-hr standard on California certification fuel. While it is
possible that individual engines certified on California fuel may
experience a slightly different offset when operated on federal diesel
fuel (e.g., when a cetane number is much different between the fuels),
EPA believes that this will be the exception and that in-use
performance on federal diesel fuel will average about 3.8 g/Bhp-hr. The
use of federal fuel in engines certified on California fuel is
consistent in this case with the fuel use provisions of sections 246(b)
and 241(2), since EPA has concluded that such engines indeed comply
with the clean fuel vehicle requirements on federal diesel fuel.
As another way of harmonizing the CARB LEV program and the CFF
program to ensure a sufficient number of HDDEs will be available by
1998 for the fleet program, EPA will only test engine families which
were certified to CFV standards on California diesel fuel on diesel
fuel meeting California specifications during any Selective Enforcement
Audit (SEA) testing or in-use recall enforcement testing. The Agency
believes that if manufacturers of HD CFVs certified on California fuel
perceive that their engines may be subject to later EPA testing on
federal diesel fuel, then they may desire to perform additional testing
of these engines on federal certification diesel fuel for the purpose
of assuring themselves of in-use compliance on federal diesel fuel.
This approach to SEA and in-use recall testing should assure
manufacturers that they will not need to perform any additional testing
at certification beyond that required for California certification.
Fuel meeting California diesel test fuel specifications is an
acceptable test fuel under the FTP because it meets the federal fuel
specifications. This policy of the Agency using fuel meeting California
diesel test fuel specifications for SEA and recall testing applies only
to CFVs. If the Agency becomes aware of changed circumstances which
indicate that this policy is inappropriate, the Agency reserves the
right to discontinue this policy.
For gasoline-fueled HD CFVs, EPA is aware of no evidence to suggest
any significant difference in emissions between such vehicles operating
on federal and California certification gasolines; thus the technical
basis for separate standards which exists for diesels does not apply
for gasoline engines. Commenters did not respond to the issue of the
appropriateness of a single standard for all HDEs. However, EPA
believes that in general, a single standard for all fuels provides
equity among manufacturers of different types of engines for this
program. Also, section 245 of the Act seems to indicate that Congress
intended for there to be a single heavy-duty CFV standard. Therefore,
as for diesel engines, EPA today also promulgates a standard of 3.8 g/
Bhp-hr for gasoline clean-fuel vehicle engines certified on federal
gasoline test fuel. As with diesel engines, gasoline engines
demonstrating compliance with the California 3.5 g/Bhp-hr standard on
California gasoline certification fuel will be eligible for a federal
certificate.
Given the arguments above, as well as the fact that manufacturers
have more than three years before the purchase requirements for clean-
fuel fleet vehicles begin, EPA believes that several heavy-duty diesel
engine families will achieve a standard of 3.8 g/Bhp-hr NMHC + NOX
on federal certification fuel or 3.5 g/Bhp-hr NMHC + NOX on
California certification fuel by the 1998 model year. Also, EPA
believes that most gasoline-fueled HDE families can meet a standard of
either 3.8 g/Bhp-hr on federal certification fuel or 3.5 g/Bhp-hr on
California fuel by the 1998 model year. These clean fuel vehicle
standards will apply to HDEs used in clean-fuel fleet vehicles of 8,501
to 26,000 lbs. GVWR to meet the purchase requirements of the fleet
program.
b. Heavy-Duty ULEV and ZEV Standards. As previously discussed,
section 246(f)(4) of the CAA requires EPA to promulgate emission
standards for ULEVs and ZEVs, for the purpose of determining fleet
program credits. The provision states that the standards:

* * * shall be more stringent than those otherwise applicable to
clean-fuel vehicles under this part* * * . The standards* * *for
[light-duty] vehicles* * *shall conform as closely as possible to
standards which are established by the State of California for ULEV
and ZEV vehicles in the same class. For vehicles of 8,500 lbs. GVWR
or more, the Administrator shall promulgate comparable standards for
purposes of this subsection.

EPA interprets this comparability criteria to mean that ULEV and
ZEV standards for heavy-duty engines should require approximately the
same percentage of emission reduction compared to heavy-duty CFV LEV
standards as light-duty CFV ULEV and ZEV standards require compared to
light-duty CFV LEV standards. Under this provision, EPA must determine
the appropriate level for the heavy-duty ULEV and ZEV standards. EPA
proposed this interpretation and did not receive any comments objecting
to it.
EPA also believes it is appropriate to take California's ULEV and
ZEV standards into consideration and attempt to harmonize the federal
and California standards where possible. As mentioned above in the
section pertaining to the feasibility of the HD CFV LEV standard, EPA
believes such harmonization is valuable because it helps create a
single larger market for heavy-duty ULEVs and ZEVs rather than two
smaller markets. A single larger market makes it more economical for
manufacturers to produce heavy-duty ULEVS and ZEVs, which makes it more
likely that manufacturers will choose to produce vehicles that can
participate in the federal program. (The federal program does not have
a sales mandate for manufacturers, so their participation is voluntary
and controlled, in part, by market demand for their products.)
EPA also believes it has authority to consider harmonization of
federal heavy-duty ULEV and ZEV standards and California incomplete
medium-duty vehicle and diesel engine ULEV and ZEV standards in setting
the federal standards.\28\ As explained above, EPA interprets
``comparable standards'' to mean that heavy-duty CFV ULEV and ZEV
standards must be comparable to light-duty CFV ULEV and ZEV standards.
Since the Act requires EPA to establish federal light-duty ULEV and ZEV
standards that conform as closely as possible to California's light-
duty ULEV and ZEV standards, harmonization of the federal heavy-duty
ULEV and ZEV standards and California incomplete medium-duty vehicle
and diesel engine ULEV and ZEV standards could be part of the
comparability determination. In addition, the direction of section
246(h) to set ``comparable standards'' gives EPA some discretion in
establishing standards. EPA believes it is appropriate to consider
California's standards in exercising this discretion. EPA believes
that, since the federal HD ULEV and ZEV standards are voluntary credit-
generating standards, their intended purpose is primarily to provide
compliance flexibility for manufacturers and fleet operators. The
Agency's goal then, in selecting these standards, is to provide the
maximum flexibility allowable under section P246(f)(4) of the Act,
while ensuring that there will be no negative impacts on the
environment.
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\28\Beginning with the 1995 model year, CARB's medium-duty
vehicles include vehicles with a GVWR of 14,000 pounds or less.
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i. Ultra low-emission vehicle standards. EPA is adopting standards
for heavy-duty ULEVs NMHC+NOX, CO, particulate, and formaldehyde
emissions as specified below in Table 5. These standards are the same
as those that were proposed, except the formaldehyde standard, which is
lower than originally proposed. In the opening statement at the public
hearing for the proposal and in a memorandum that was placed in the
docket and distributed at the public hearing,\29\ EPA informed the
public that the proposed standard for formaldehyde was a typographical
error and requested comment on the change of the heavy-duty ULEV
standard to the level specified in Table 5. EPA did not receive any
comments objecting to this level for the formaldehyde ULEV standard.
The final heavy-duty ULEV standards require reductions in emissions
that are comparable to the respective emission reductions required of
light-duty ULEVs, and are consistent with the respective requirements
of the California LEV program.
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\29\U.S. Environmental Protection Agency, Office of Mobile
Sources, ``Request for Comment on Revised Formaldehyde Standard for
Heavy-Duty ULEVs for the Clean Fuel Fleet NPRM,'' July 12, 1993,
Memorandum from Bryan J. Manning through Tad Wysor to docket A-92-30
(Document Number III-A-03).
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As proposed, EPA is setting a combined NMHC + NOX HD CFV ULEV
standard that is approximately a 30 percent reduction from the HD CFV
LEV standard. The comparable light-duty CFV ULEV standards require
reductions from light-duty CFV LEV standards of 38 to 50 percent of
NMOG emissions and 45 to 50 percent for NOX emissions. Even though
EPA has separate NMOG and NOX standards for light-duty CFV ULEVs,
the Agency does not believe it is required to establish such separate
standards for heavy-duty CFV ULEVs. Rather, EPA believes it is
appropriate to have a combined NMHC + NOX heavy-duty CFV ULEV
standard because heavy-duty CFV LEV standards have a combined NMHC +
NOX standard rather than separate NMOG and NOX standards (as
do light-duty CFV LEVs and ULEVs). Furthermore, a combined NMHC +
NOX standard is consistent with the California incomplete medium-
duty vehicle and diesel engine ULEV standard. EPA proposed this
interpretation and did not receive any comments objecting to a combined
NMHC + NOX standard for HDEs.
EPA also is setting specific emission standards for CO and
particulates that require a reduction in emissions from the heavy-duty
CFV LEV standards of 50 to 54 percent and 50 percent, respectively, as
proposed. (For both CO and particulates, heavy-duty CFV LEVs must meet
the same standards as do conventional heavy-duty vehicles. Thus, for
these standards, the reductions in emissions for heavy-duty CFV ULEV
standards are the same whether they are compared to conventional or CFV
LEV heavy-duty standards.) The comparable light-duty CFV ULEV standards
require reductions in CO and particulate emissions of 50 percent each
from light-duty CFV LEV standards. These federal heavy-duty ULEV
standards are identical to California's incomplete medium-duty vehicle
and diesel engine ULEV standards.
Finally, EPA is also setting a specific heavy-duty ULEV standard
for formaldehyde. The comparable light-duty CFV ULEV standard requires
a reduction in emissions ranging from 39 to 52 percent from light-duty
CFV LEV standards. Though formaldehyde is not regulated for heavy-duty
CFV LEVs, formaldehyde is regulated in the light-duty CFV ULEV
standards. EPA believes that heavy-duty vehicles that emit formaldehyde
are likely to participate in the CFV ULEV program. Because emissions of
formaldehyde are of significant concern to EPA and to Congress, as
evidenced by the inclusion of formaldehyde standards for light-duty CFV
LEVs and the inclusion of formaldehyde as a hazardous air pollutant,
EPA believes it is appropriate to include standards for formaldehyde
emissions in the heavy-duty CFV ULEV program. EPA has the authority to
regulate formaldehyde emissions not only under section 246(f)(4), but
also under CAA sections 202(a) and 301(a). Also, the CARB LEV program
includes a formaldehyde ULEV standard for diesel engines and incomplete
medium-duty vehicles. Therefore, it is consistent with the CARB LEV
program to set a formaldehyde standard for federal HD ULEVs. The
standard promulgated today is identical to CARB's incomplete medium-
duty vehicle and diesel engine ULEV formaldehyde standard.

Table 5.--Emission Standards for Model Year 1998 and Later Heavy-Duty Vehicles
----------------------------------------------------------------------------------------------------------------
NMHC + Particulate
Vehicle type THC (g/ NOX (g/ NOX (g/ CO (g/Bhp- 1 (g/Bhp- OMHCE (g/ HCHO (g/
Bhp-hr) Bhp-hr) Bhp-hr) hr) hr) Bhp-hr) Bhp-hr)
----------------------------------------------------------------------------------------------------------------
Conventional Gasoline = 14,000
GVWR............................ 1.9 4.0 ......... 37.1 ........... 1.9 .........
Conventional Diesel.............. 1.3 4.0 ......... 15.5 0.10 1.3 .........
LEV Certified on Federal Fuel.... (2) (2) 3.8 (2) (2) (2) .........
LEV Certified on California Fuel. (2) (2) 3.5 (2) (2) (2) .........
ULEV............................. (2) (2) 2.5 7.2 0.05 (2) 0.025
ILEV............................. (2) (2) 2.5 14.4 0.10 (2) 0.050
----------------------------------------------------------------------------------------------------------------
(\1\) Standards for particulate matter (PM) apply only to diesel-fueled vehicles.
(\2\) HD CFVs must meet conventional vehicle standards for THC, NOX, CO, PM, and OMHCE.

Based on the Acurex report, Regulatory Support Document, and
comments received from the Natural Gas Vehicle Coalition, EPA believes
that alternative fuel vehicle technology will be available to meet
these standards by 1998, and that gasoline and diesel engines may also
be able to achieve these ULEV levels by that time or shortly
thereafter. In any event, covered fleet operators are never required to
purchase ULEVs to meet the requirements of the fleet program.
ii. Zero-emission vehicle standards. Zero-emission vehicles (e.g.
electric vehicles) are vehicles which have no emissions of the
pollutants of concern. Therefore, as proposed, EPA today establishes
heavy-duty ZEV standards of zero for NMHC + NOX, CO, particulates,
and formaldehyde. (Emissions from non-fuel sources (e.g. tires, seats,
paint, etc.) will likely exist as they do for conventional vehicles and
other CFVs.) These final heavy-duty ZEV standards each require a 100
percent reduction in emissions from the heavy-duty LEV standards, which
for each pollutant is comparable to the respective emission reductions
required of light-duty CFV ZEVs. Furthermore, these federal ZEV
standards are identical to California's incomplete medium-duty vehicle
and diesel engine ZEV standards.
Compliance with the ZEV standards may be assessed through
engineering analysis, which shall include a description and analysis of
all primary or auxiliary equipment and engines which concludes that no
emissions of the stated pollutants is possible. The engineering
analysis must determine that the vehicle fuel system(s) does not
contain either carbon or nitrogen compounds (including air) which, when
burned, form the above regulated exhaust emissions. Such criteria will
also assure that evaporative emissions will not occur. Given these
criteria there is no need to perform emission testing because the above
pollutants cannot be emitted from the vehicle. However, compliance for
ZEVs may be assessed through testing by performing the tests required
by Parts 86 and 88 (Federal Test Procedure) when applicable.
Any vehicle with additional power system(s) or auxiliary engine(s)
that might produce regulated pollutants (e.g. hybrid vehicle or an
electric vehicle with an auxiliary power source to run other vehicle
systems) will be subject to the testing requirements of Part 86 or Part
88 or future applicable regulations and might not qualify as a ZEV. A
ZEV with a heater will be considered a ZEV as long as the heater will
not operate at an ambient temperature above 40 deg.F and the heater's
power/fuel source does not have evaporative emissions in use.
c. Other Issues--i. Flexible- and Dual-Fuel HDEs. EPA is not
promulgating a set of emission standards for flexible- and dual-fuel
heavy-duty vehicles. (Flexible- and dual-fuel vehicles are also
commonly referred to as variable- and bi-fuel vehicles, respectively.)
Section 243(d) of the Act prescribes emission standards for flexible-
and dual-fueled light-duty vehicle and light-duty trucks. EPA is
establishing these standards today (see II.A.1.a). The directive of
section 243(g) that ``nothing in this section shall apply to heavy-duty
engines'' makes it clear that section 243(d) does not require EPA to
establish flexible- and dual-fueled standards for heavy-duty engines.
Even if EPA has authority to promulgate such standards (a question
which we do not answer here), EPA does not think it is appropriate to
exercise that authority at this time. As Natural Gas Vehicle Coalition
suggested in their comments, it is possible that similar standards
could be implemented for HDEs in the same manner as prescribed in the
statute for light-duty vehicles and light-duty trucks. However, as
described in the proposal, separate NMHC standards are not necessary
for flexible- or dual-fuel HDEs since similar behavior of NMHC (or the
equivalent (NMHCE)) would be expected for all fuel types. In addition,
as discussed above, heavy-duty vehicles operated on conventional
gasoline and diesel fuel will be able to comply with the CFV standards
by 1998, and thus, there is not a compelling technical reason to have
slightly higher standards for the vehicle when it is operated on clean
alternative fuel. For all these reasons, EPA is not adopting separate
standards for flexible- or dual-fuel HDEs.
Section 241(2) defines clean alternative fuel for flexible- or
dual-fuel vehicles and engines as the fuel(s) on which such vehicles
are certified to the CFV standards. EPA concludes from this statutory
language that engines certified on California gasoline or diesel fuel
only will need to operate exclusively on that fuel in covered
nonattainment areas. (For single-fuel vehicles and engines, section
241(2) requires operation in covered areas on the fuel(s) on which they
``comply'' with the CFV standards. As discussed above, EPA has
determined that single-fuel HDEs certified on California gasoline or
diesel fuel comply with the HD CFV standard on federal fuels.)
ii. Optional LDT Certification. For a number of years,
manufacturers have had the option of certifying their HDEs used in
vehicles between 8501 and 10,000 lbs. GVWR using the LDT emission
standards and provisions. This provision is found in 40 CFR 86.085-
1(b). EPA finds no reason why the treatment of CFVs should be different
than conventional vehicles in this regard, and thus for consistency EPA
will also make this option available for clean-fuel HDEs.
iii. Heavy-duty test procedures. While this action establishes NMHC
+ NOx standards for heavy-duty vehicles and engines, EPA regulations
historically have not included test procedures for the measurement of
methane separate from other hydrocarbons, and thus the calculation of
NMHC emissions would not have been possible. Prior to today's
regulations the heavy-duty test procedures only measured the total
amount of hydrocarbons (including methane), but did not separately
measure the amount of any individual hydrocarbons such as methane.
Therefore, EPA is promulgating additional test procedures for the
separate measurement of methane and calculation methods for NMHC
emissions, as discussed below. Test procedures for measurement of total
hydrocarbon (THC) emissions will be unchanged, and EPA will continue
the current practice of using a flame ionization detector (FID) for THC
measurement.
The test procedures call for the separate measurement of methane
using gas chromatography\30\ as specified in the Society of Automotive
Engineers (SAE) Recommended Practice J1151. This is consistent with
both the previously established EPA procedure for light-duty vehicles
and light-duty trucks (40 CFR 86.111-94 and 40 CFR 86.140-94), and the
California procedure for methane measurement. This approach does not
permit continuous methane measurement of exhaust samples and will
require that a bag sample be collected for all classes of vehicles and
engines. (The SAE Recommended Practice J1151 is incorporated by
reference in sections 86.111-94(b)(3)(vii) and 86.1311-94(b)(2)(iii) of
the regulatory text and is available in EPA Air Docket A-92-30.)
---------------------------------------------------------------------------

\30\Gas Chromatography--A separation technique in which a sample
of the gaseous state is carried by a flowing gas (carrier gas)
through a tube (column) containing stationary material. The
stationary material performs the separation by means of its
differential affinity for the components of the sample.
---------------------------------------------------------------------------

Under the approach for measuring NMHC, THC will first be measured
using the FID. Then, methane will be measured using gas chromatography.
This methane measurement will then be multiplied by a ``FID response
factor.'' This response factor is necessary because the FID responds
differently to methane than it does to other hydrocarbons. In order to
find what portion of the FID's THC reading is attributable to methane,
the tester must know the relationship between the FID response to other
hydrocarbons and to methane. Such a ``FID response factor'' is
calculated by noting the response of the FID, calibrated for typical
HCs, to a known quantity of methane. For example, if a sample known to
be 10.0 grams of methane gives a FID reading of 11.0 grams, then the
FID response factor is 11.0/10.0 or 1.10. The mass of NMHC is then the
difference between the THC (as measured by the FID) and the methane (as
measured by gas chromatography), multiplied by the FID response factor.
For natural gas vehicles (NGVs), the Natural Gas Vehicle Coalition
and the American Gas Association suggested that the EPA adopt the CARB
method of direct measurement of NMHC by gas chromatography. This issue
was also raised in response to the Gaseous Fuels Rule NPRM (proposed in
November, 1992), and EPA has addressed all concerns related to the
measurement of NMHC emissions for NGVs in the subsequent Gaseous Fuels
FRM. The NMHC measurement method promulgated in this section is the
same as the method established in the Gaseous Fuels FRM. If the NMHC
measurement procedure for NGVs is revisited and changed in the future,
then any revised method will apply to clean-fuel vehicle testing as
well.
In order to provide manufacturers with additional flexibility, EPA
proposes to make the measurement of methane (and subsequent
calculations) optional. Manufacturers would be allowed to measure and
report THC emissions for compliance with the NMHC standards. Since THC
emissions are the sum of the methane and NMHC emissions, they will be
higher than the NMHC emissions alone; thus, if the THC emissions are
lower than the standard, the NMHC will also be below the standard.
While this option in effect increases the stringency of the standard,
some manufacturers may find that the savings associated with using a
simpler test procedure justify certifying under this option. This is
especially true for diesels, where the methane fraction of THC
emissions is small.
iv. Averaging, trading, and banking. The Agency has previously
established an extensive credit exchange program for NOX and PM
emissions from heavy-duty engines\31\. Under this program, a
manufacturer can take emissions credits for producing vehicles that are
below the applicable standards, and then use those credits either on
its own engines within the same averaging set or to sell to other
manufacturers for use in families in the same averaging set which do
not meet the applicable standards (trading). These emission credits can
be used in the year generated or retained for later use (banking).
Fleet average emissions are unchanged by this program.
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\31\``Certification Programs for Banking and Trading of Oxides
of Nitrogen and Particulate Emission Credits for Heavy-Duty
Engines;'' Final Rule, 55 FR 30584, July 26, 1990.
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It would be inappropriate for a manufacturer to receive
certification emission credits for vehicles certified under part 88
(i.e., CFV LEVs, ULEVs and ZEVs) for participation in the fleet
program. The CFV standards are mandatory for covered fleet vehicle
purchases; to also allow manufacturer credits for certification of the
same vehicles would result in less emission reduction than is
contemplated in the Act. Thus, CFVs certified under part 88 for use in
the fleet program for either compliance or credit purposes shall be
excluded from the manufacturers' credit exchange program. By contrast,
single-fuel engines that are certified under part 86 may not
participate in the fleet program even if their emissions meet CFV
standards. Therefore, such engines may generate manufacturer
certification credits. However, dual- and flexible-fuel vehicles
certified under part 86 may only be able to generate certification
emission credits based on the least stringent standard to which the
vehicle is certified since the manufacturer has no control of the fuel
used by the vehicle owner.
In order to allow a distinction between engines which are eligible
for the fleet program and those that are not, EPA requires
manufacturers to have different engine lables. Those engines labeled
under Part 88 must include on the label an indication that this engine
is intended to be part of a clean-fuel vehicle program, and as such,
they will be excluded from the manufacturers' credit exchange programs.
Those engines labeled under Part 86 only will not include any
indication on the label that the engine meets any of the emissions
requirements of Part 88, and as such, they will be excluded from all
clean-fuel vehicle programs and may be included in a manufacturers'
credit exchange programs. EPA will allow manufacturers to divide a
clean-fueled engine family into two engine families, one labeled under
Part 88 (the Part which regulates clean-fuel fleet vehicles) an

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A94-22132. Public record. Not legal advice.