On-Road Diesel Smoke Testing

In order to promote consistency among state-operated in-use smoke testing programs, the U.S. Environmental Protection Agency has recommended the use of the SAE J1667 test procedure for highway heavy-duty diesel vehicles.

EPA has also recommended the specific opacity cutpoints of 40 percent for vehicles 1991 and newer and 55 percent for vehicles 1990 and older be used with the SAE J1667 test.

• U.S. EPA Guidance on Smoke Testing Procedure
• U.S. EPA Guidance on Opacity Cutpoints

Published: March 31, 2003