4 June 2005

The US Environmental Protection Agency (EPA) has signed a final rule implementing in-use testing requirements for heavy-duty diesel engines. Under the program, manufacturers will measure gaseous and particulate exhaust emissions from diesel engines using portable emission measurement systems (PEMS) installed onboard of the vehicle. The regulation will help to ensure that diesel emission standards are met under real-world driving conditions.

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Following a pilot highway truck program starting this year, the in-use testing will became mandatory in 2007 for highway engines. A similar program for nonroad engines is expected to commence in 2010. In cooperation with their customers, engine manufacturers will test fleet or customer-owned in-use trucks and other diesel vehicles. Compliance will be monitored by testing in-use diesel engines to determine brake-specific emissions during normal vehicle operation. If noncomplying engines are identified, the EPA will use the data to make evaluations about the possible need to pursue further actions. The data will also be available to the public.

EPA expects that 13 heavy-duty diesel engine manufacturers will be involved in the pilot program. The total annual cost is estimated at $1.7 million. Since the in-use program is expected to simplify laboratory testing requirements, the EPA believes it will lower the overall cost of future engine testing.

The program has been developed in cooperation between the EPA, the California Air Resource Board (ARB), and the Engine Manufacturers Association (EMA). The ARB will adopt a parallel in-use testing program in California.

Source: US EPA