EPA is proposing a manufacturer-run, in-use emissions testing program for heavy-duty diesel trucks. Under this program, engine manufacturers will measure emissions from their diesel engines in highway applications using portable onboard emission measurement systems.

A pilot program is proposed to begin in 2005 with the fully enforceable program beginning in 2007 when the new requirements take effect. The proposal stems from a settlement agreement between EPA and the Engine Manufacturers Association that was announced in June of 2003.

This cooperative effort between EMA and EPA represents a significant advance in helping to ensure that the benefits of more stringent emission standards are realized under real-world driving conditions.

A pre-publication copy of the proposal is available online at: http://www.epa.gov/otaq/hd-hwy.htm.

For more information on EPA's clean diesel program, visit: http://www.epa.gov/cleandiesel.

6/1/2004