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Supporting Tougher Clean Diesel Standards, Advanced Technology Will Test Real-World Truck and Bus Emissions

Release Date: 06/03/2005
Contact Information:

Contact: John Millett, 202-564-4355 /

(Washington, D.C.-- 06/03/05) Testing highway diesel truck and bus emissions will be more accurate, less expensive, and more effective under a new in-use testing program announced today by EPA. Using state-of-the-art technology, the program will ensure EPA's stringent emission standards are met under real-world driving conditions and deliver increased public health benefits. This program is the result of unprecedented cooperation involving EPA, the California Air Resource Board (ARB), and diesel engine manufacturers.

"This program is a dramatic addition to the EPA's Clean Diesel Campaign and will result in healthier air for all Americans," said EPA Assistant Administrator for Air and Radiation Jeff Holmstead. "This collaborative effort with engine manufacturers will help ensure that diesel trucks run cleaner for as long as they are on our roads."

While vehicles from a selected sample of typical trucks and buses are in operation, portable measuring devices attached to the engine will assess exhaust emissions of hydrocarbons, carbon monoxide, nitrogen oxides, and particulate matter. The program begins this month with a pilot program that calls on manufacturers to recruit volunteer test vehicles from fleets or individual owners. The program will expand nationwide starting with 2007 model year diesel trucks.

Prior to this program, testing diesel engine emissions required removal of the engine from the truck and testing in laboratories. These former testing procedures were more cumbersome, less accurate and more expensive. This new program also brings this successful partnership to the research and development arena with the initiation of a new development program to further demonstrate and refine the portable emission measurement technology.

In a companion action also announced today, EPA is revising the test procedures to reflect current state-of-the-art portable emission measurement technology. This rule also creates unified testing requirements for all engines that will streamline laboratory efforts for EPA and industry.

For more information on the testing program, visit: . For information on the companion action, visit: .