The EPA has announced an in-use emissions testing program for diesel truck and bus emissions that is more accurate, less expensive, and more effective than prior testing techniques. The program is the result of cooperation involving EPA, the California Air Resource Board (ARB), and diesel engine manufacturers.

Vehicles under test will have portable measuring devices attached to the engine during normal operation for five days to assess exhaust emissions of hydrocarbons, carbon monoxide, nitrogen oxides, and particulate matter.

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.

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.

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.

Resources:

• EPA Final Rule In-Use Testing for Heavy-duty Engines and Vehicles landing page