United States             Air and Radiation         EPA420-F-00-022
Environmental Protection                         May 2000

Office of Transportation and Air Quality
 Proposed Heavy-Duty Engine and
 Vehicle Standards and Highway
 Diesel Fuel Sulfur Control
The U.S. Environmental Protection Agency (EPA) is proposing a major
program to significantly reduce emissions from heavy-duty engines and
vehicles. This comprehensive national control program regulates the
heavy-duty vehicle and its fuel as a single system. We are proposing
new emission standards that will begin to take effect in 2007 and
corresponding diesel fuel requirements that take effect in 2006. If fully
implemented as proposed, this program will reduce emissions of oxides
of nitrogen (NOx) and nonmethane hydrocarbons (NMHC), key
ingredients in ozone, by 2.8 million and 305,000 tons per year in 2030,
respectively. Particulate emissions from these vehicles would be
reduced by 110,000 tons per year in 2030.

These proposed standards are based on the use of high-efficiency cata-
lytic aftertreatment devices or comparably effective advanced technolo-
gies. Because these devices are damaged  by sulfur, we are also propos-
ing new fuel quality requirements to remove most of the sulfur from
highway diesel fuel by the middle of 2006. These changes form the
second phase of a two-phase Agency initiative, beginning with the
previously set 2004 heavy-duty engine standards, to reconcile the heavy-
duty highway engine with the environment.
                                       > Printed on Recycled Paper

              This second phase will achieve emission reductions of upwards of 90
              percent or more over levels achieved by the phase 1 reductions, and will
              provide a clean diesel fuel in time for implementation of the light-duty
              Tier 2 standards. As a result, diesel vehicles of all sizes will achieve
              gasoline-like exhaust emission levels, in addition to their inherent advan-
              tages over gasoline vehicles with respect to fuel  economy, lower green-
              house gas emissions, and lower evaporative hydrocarbon emissions.

              Diesel engines overwhelmingly dominate the bus and large truck markets
              and have been capturing a growing share of the light heavy-duty vehicle
              market over the last decade. The impact of diesel engines on air quality
              may grow even larger if automobile manufacturers carry out stated plans
              to increase sales of diesel-powered light-duty trucks and cars over the
              next few years. In light of the air quality concerns, we published an
              Advance Notice of Proposed Rulemaking (ANPRM) in May 1999 to
              investigate  the possibility of bringing about dramatic improvements in
              diesel emissions control through a combination of fuel and vehicle
              changes. The fuel changes would enable not just heavy-duty diesel
              emissions control, but would also help to enable light-duty diesels to
              meet  our recently adopted Tier 2 standards. Based on the air quality
              concerns and the comments we received on the ANPRM., we are now
              proposing a comprehensive national control program that covers heavy-
              duty vehicles operated on any  fuel.


Heavy-Duty  We are proposing a paniculate matter (PM) emissions standard for new
Engines      heavy-duty engines of 0.01 grams per brake-horsepower-hour (g/bhp-hr),
              to take full effect in the 2007 heavy-duty engine (HDE) model year. We
              are also proposing standards for oxides of nitrogen (NOx) and
              nonmethane hydrocarbons (NMHC) of 0.20 g/bhp-hr and 0.14 g/bhp-hr,
              respectively. These NOx and NMHC standards would be phased in
              together between 2007 and 2010, for diesel engines. The phase-in would
              be on a percent-of-sales basis: 25 percent in 2007, 50 percent in 2008, 75
              percent in 2009, and 100 percent in 2010. Because of the more advanced
              state of gasoline engine emissions control technology, these engines
              would be fully subject to these standards in the 2007 model year, al-
              though we request comment on phasing in these standards as well. In
              addition, we are  proposing formaldehyde emission standards and new
              requirements for crankcase emissions control on turbocharged diesel


Proposed Standards for HDEs
0.01 g/bhp-hr
0.20 g/bhp-hr
0.14 g/bhp-hr
Proposed standards for complete heavy-duty vehicles (HDVs) would be
implemented on the same schedule as for engine standards. For certifica-
tion of complete vehicles between 8500 and 10,000 pounds gross vehicle
weight rating (GVWR), the proposed standards are 0.2 grams per mile
(g/mi) for NOx, 0.02 g/mi for PM, and 0.195 g/mi for NMHC. For
vehicles between 10,000 and 14,000 pounds, the proposed standards are
0.4 g/mi for NOx, 0.02 g/mi for PM, and 0.230 g/mi for NMHC. These
standards levels are roughly comparable to the proposed engine-based
standards in these size ranges. Note that these standards would not apply
to vehicles above 8500 pounds that we classify as medium-duty passen-
ger vehicles as part of our Tier 2 program because of their primary use as
passenger vehicles (the final standards for these vehicles are in 65 FR
6698, February 10, 2000).
Proposed Standards for HDVs
0.02 g/mi
0.02 g/mi
0.2 g/mi
0.4 g/mi
0.1 95 g/mi
0.230 g/mi
We are proposing to revise the evaporative emissions standards for
heavy-duty engines and vehicles, effective in the 2007 model year. The
proposed standards for 8500 to 14,000 pound vehicles are 1.4 and 1.75
grams per test for the 3-day diurnal and supplemental 2-day diurnal tests,
respectively. Slightly higher standards levels of 1.9 and 2.3 grams per
test would apply for vehicles over 14,000 pounds. These proposed
standards represent more than a 50 percent reduction in the numerical
standards as they exist today.

Proposed Evaporative Emission Standards
> 14,000
3-Day Diurnal Test
1.4 g/test
1 .9 g/test
Supplemental 2-Day Diurnal Test
1.75 g/test
2.3 g/test
We are proposing that diesel fuel sold to consumers for use in highway
vehicles have a sulfur content no greater than 15 parts per million (ppm),
beginning June 1, 2006. This proposed sulfur cap is based on our assess-
ment of how sulfur-intolerant advanced aftertreatment technologies will
be, and a corresponding assessment of the feasibility of low-sulfur fuel
production and distribution. We are seeking comment on voluntary op-
tions for providing refiners with  flexibility in complying with the low
sulfur highway diesel fuel program. In addition, we request comment on
some potential flexibility provisions to assist small refiners in complying
with the program.
Without significant new controls on motor vehicle emissions, millions of
Americans will continue to breathe unhealthy air. The standards proposed
would result in substantial benefits to the public health and welfare
through significant annual reductions in emissions of NOx, PM, NMHC,
carbon monoxide, sulfur dioxide, and air toxics. If fully implemented as
proposed, this program will reduce emissions of NOx and NMHC, key
ingredients in ozone, by 2.8 million and 305,000 tons per year in 2030,
respectively. Particulate emissions from these vehicles would be reduced
by 110,000 tons per year in 2030.

Ozone causes a range of health problems related to breathing, including
chest pain, coughing, and shortness  of breath. PM is deposited deep in the
lungs  and causes premature death, increased emergency room visits, and
increased respiratory symptoms and disease. With both ozone and PM,
children and the elderly are most at risk. In addition, ozone, NOx, and PM^
adversely affect the environment in various ways, including crop damage,
acid rain, and visibility impairment. Numerous studies also link diesel
exhaust to increased incidence of lung cancer.

       of the
The significant environmental benefits of this program would come at an
average cost increase of about $1000 to $1600 per new vehicle, depend-
ing on the vehicle size. We estimate that the overall cost associated with
lowering the sulfur cap from the current level of 500 ppm to the 15 ppm
level proposed today will be approximately 3-4 cents per gallon, com-
prised of an approximately 4  cents per gallon increased cost to produce
and distribute the fuel, and a cost offset of about 1 cent per gallon or
more  from the vehicle maintenance savings that result from the use of the
cleaner fuel.
We welcome your comments on this proposal. For instructions on sub-
mitting written comments, please see the Federal Register notice. You
may submit written comments to EPA up to 90 days after the proposed
rule is signed by the EPA Administrator. It is available from the EPA Air
Docket by calling 202-260-7548; please refer to Docket No. A-99-06. In
addition, you can access the proposed rule and related documents elec-
tronically on the Office of Transportation and Air Quality Web site at:

      http ://www. epa.gov/otaq/di esel .htm

The address for submitting written comments is:

      Margaret Borushko (Docket No. A-99-06)
      U.  S. Environmental Protection Agency
      Office of Transportation and Air Quality
      2000 Traverwood Drive
      Ann Arbor, MI 48105

You may also submit comments by email to diesel@,epa.gov.

In addition, public hearings will be held in Los Angeles, Denver, New
York City, Chicago, and Atlanta approximately three weeks after publica-
tion of the proposed rule in the Federal Register. Additional information
about the hearings will be published in a supplemental notice in the
Federal Register in the near future.
You can access documents related to the proposed rule and the ANPRM
electronically at the Internet site listed above, or by contacting Margaret
Borushko at the address given above.