United States Air and Radiation EPA420-F-99-034
Environmental Protection October 1999
Agency http://www.epa.gov/oms
Office of Mobile Sources
Regulatory
Announcement
Proposed Strategy to Reduce
Emissions from Heavy Duty Vehicles
The U.S. Environmental Protection Agency (EPA) is announcing a
strategy to significantly reduce emissions from on-highway heavy-duty
vehicles (vehicles with a gross vehicle weight rating greater than 8,500
pounds), including diesel and gasoline engines used in large
commercial trucks, large versions of full-size pickup trucks, passenger
vans, and the largest sport utility vehicles. Vehicles weighing up to
8,500 pounds would be covered under the tailpipe emission standards
that EPA proposed in May, commonly known as Tier 2 standards. The
first phase of the strategy to reduce emissions from heavy-duty trucks
would take effect starting with the 2004 model year. The second phase
could take effect as early as 2007. This strategy will play an important
role in reducing the harmful health and environmental effects of ozone
and particulate matter.
Highlights of Proposed Rule—The First Phase of the Strategy
EPA is proposing new emission standards that will significantly reduce
emissions from heavy-duty vehicles. These new standards are part of a
two-phase strategy to reduce emissions from heavy-duty trucks and the
largest passenger vans and sport utility vehicles (SUVs). The proposed
standards are just the first phase of this strategy and would require
gasoline trucks to be 78 percent cleaner and diesel trucks to be 50 per-
cent cleaner than today's models. A reduction in particulate matter of
about 55,000 tons per year would also be achieved.
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In order to ensure the best operation of these vehicles and their pollution
control systems, the proposal includes several actions regarding new
emission limits and improved testing procedures. For example, for
vehicles weighing between 8,500 and 14,000 pounds (gross vehicle
weight), EPA is proposing to require on-board diagnostics systems to
help identify any possible failure of components of the emission control
system.
The following tables list the proposed oxides of nitrogen (NOx) and
hydrocarbon (HC) standards for gasoline and diesel vehicles with a gross
vehicle weight above 8,500 pounds. The current NOx standard for both
diesel and gasoline vehicles is 4.0 grams per brake horsepower hour (g/
bhp-hr). The current HC standard for diesel is 1.3 g/bhp-hr and for
gasoline is 1.1 g/bhp-hr.
Diesel Vehicles
Gross Vehicle Weight
Combined Standard
NOx and HC
8,500 pounds and above
2.4 g/bhp-hr
Gasoline Vehicles
Gross Vehicle Weight
8,500 - 10,000 pounds
10,001 - 14,000 pounds
14,001 pounds and above
NOx
0.9 grams per mile
1.0 grams per mile
HC
0.28 grams per mile
0.33 grams per mile
1.0 g/bhp-hr (combined NOx and HC)
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of
The significant environmental benefits of this program would come at an
average projected long-term cost increase of less than $400 per vehicle
for heavy-duty diesel engines and less than $300 per vehicle for heavy-
duty gasoline vehicles and engines.
to be Done—The
EPA plans to propose late this year or early next year to again signifi-
cantly reduce pollution from heavy-duty trucks. The Agency is consider-
ing even more stringent standards that could take effect as early as 2007
and reduce NOx emissions by between 75 and 90 percent even beyond
today's proposal. Emissions of particulate matter could be reduced by 80
to 90 percent.
As part of this second phase, in order to enable new emissions-control
technology on heavy trucks, EPA will be proposing the reduction of the
sulfur content of highway diesel fuel by approximately 90 percent from
its current level of 500 ppm. EPA already has proposed to significantly
reduce sulfur levels in gasoline in the Tier 2 proposal.
and
Without significant new controls on motor vehicle emissions, millions of
Americans will continue to breathe unhealthy air. The emission reduc-
tions from this program would provide much-needed assistance to states
facing ozone and particulate matter air pollution problems.
Ozone causes a range of health problems related to breathing, including
chest pain, coughing, and shortness of breath. Particulate matter is
deposited deep in the lungs and causes premature death, increased
emergency room visits, and increased respiratory symptoms and disease.
With both ozone and particulate matter, children and the elderly are most
at risk. In addition, ozone, nitrogen oxides, and particulate matter ad-
versely affect the environment in various ways, including crop damage,
acid rain, and visibility impairment
Background
In a separate action, on May 1, 1999, EPA proposed tighter tailpipe
emission standards for cars and light trucks weighing up to 8,500
pounds. Commonly referred to as Tier 2, these standards would take
effect beginning in 2004 when manufacturers would start producing
passenger cars that are 77 percent cleaner than those on the road today.
Light-duty trucks, such as SUVs, which now are subject to standards
that are less protective than those for cars, would be as much as 95
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percent cleaner under the new standards. EPA's heavy-duty engines
proposal will address all vehicles weighing more than 8,500 pounds, and
ensure that the heaviest passenger vans and SUVs will also meet Tier 2
standards.
In addition, in late 1998, the Agency signed consent decrees with several
of the largest heavy-duty diesel engine manufacturers to address several
in-use emission problems. This proposal contains several new provisions
for the heavy-duty diesel engine manufacturers which have arisen
because of the issues highlighted by these consent decrees. These provi-
sions include new emission tests and associated limits that are designed
to ensure that heavy-duty diesel engines meet emission standards in
actual use and over a broad range of operating conditions. In the consent
decrees, the manufacturers agreed to introduce cleaner new engines and
rebuild older engines to cleaner levels. Under the agreements, the com-
panies will meet emission levels for heavy-duty diesel engines beyond
what the law requires by October 2002.
Public
We welcome public comments on this proposed program from all inter-
ested parties. Wherever applicable, please submit full supporting data
and detailed analyses to allow EPA to make maximum use of the com-
ments. We especially encourage specific suggestions for changes.
There will be a public hearing regarding the proposal on November 2 in
Philadelphia, Pennsylvania, at the Top of the Tower located at 1717 Arch
Street 51st floor. You may submit written comments to EPA up to 30
days after the public hearing. For instructions on submitting written
comments, please see the Federal Register notice. It is available from the
EPA Air and Radiation Docket by calling (202) 260-7548; please refer to
Docket No. A-98-32. The proposed rule and related documents are
available electronically via the Office of Mobile Sources's web site at:
http ://www. epa.gov/oms/hd-hwy.htm
For
Additional documents on the proposed rule are available electronically at
the Internet site listed above, or by contacting:
U.S. Environmental Protection Agency
Office of Mobile Sources
2000 Traverwood Dr.
Ann Arbor, MI 48105
(734)214-4349
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