On-Road Heavy-Duty Diesel Engine Reduced Emission Standards

This page last reviewed January 6, 2005

Reduced Emission Standards for 2007 and
Subsequent Model Year Heavy-Duty Diesel Engines

In October of 2000, the United States Environmental Protection Agency (U.S. EPA) adopted a rule that reaffirmed lowered emission standards for 2004 and subsequent model year heavy-duty diesel engines (65 FR 59896, October 6, 2000). Notably, the rule reduced the current oxides of nitrogen emissions standard by 50 percent. This rulemaking also included supplemental test procedures that represented most in-use driving conditions, as compared to the existing Federal Test Procedure. However, these test procedures are applicable for 2007 and subsequent model years even though several engine manufacturers will be required to produce engines meeting the new test requirements from 2002 through 2004 due to the consent decrees. Consequently, the Air Resources Board (ARB) adopted similar supplemental test requirements in December of 2000, that apply to model year 2005 and subsequent heavy-duty diesel engines.

In January of 2001, the U.S. EPA promulgated a Final Rule to reduce emission standards for 2007 and subsequent model year heavy-duty diesel engines (66 FR 5002, January 18, 2001). These emission standards represent a 90 percent reduction of oxides of nitrogen emissions, 72 percent reduction of non-methane hydrocarbon emissions, and 90 percent reduction of particulate matter emissions compared to the 2004 model year emission standards. In addition to the reduced emission standards, the U.S. EPA adopted minor changes to the previously adopted supplemental test procedures, the Not-to-Exceed test and the European Stationary Cycle test. The ARB is proposing to adopt similar emission standards and test procedures to reduce emissions from 2007 and subsequent model year heavy-duty diesel engines and vehicles. The proposal also includes the U.S. EPA's modifications to the previously adopted supplemental test procedures.

Hearing Notices / Proposed Regulations / Related Programs

Mailout MSC 01-08	Use this link to view the mailout for the proposed amendments. Mailout MSC #01-08 is the Memo Regarding Consideration of Amendments to Adopt Reduced Emission Standards for 2007 and Subsequent Model Year Heavy-Duty Diesel Engines and Vehicles.
Mailout MSC-01-15	Use this link to view the mailout to announce the availability of the documents related to the proposed amendments. The available documents include the Public Hearing Notice, the Initial Statement of Reasons for Rulemaking, and Attachments to the Initial Statement of Reasons.
Formal Regulatory Documents	Use this link to view the formal regulatory documents. These documents include, but are not limited to, the Staff Report, Hearing Notice, and 15-day notice(s).

Where Can I Get More Information?

For more information, please contact Stephan Lemieux at (626) 450-6162.

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Diesel Activities: Mobile Vehicles and Equipment
On-Road Heavy-Duty Vehicle Program