Evidence Grows That EPA Knew About Diesel Engine Test Flaws

Evidence mounted that the Environmental Protection Agency knew long before it lowered the boom on diesel engine makers that their electronically controlled engines had pollution problems and that EPA’s own certification test was so poorly designed it failed to detect illegal emissions levels.

Also, Cummins Engine Co. last week backed up the claim by Sweden’s Volvo Truck Corp. that an EPA official was told at 1994 meeting in Geneva, Switzerland, about the strategies engine makers were employing to pass the U.S. certification test (TT, 11-23-98, p. 1). A third engine manufacturer and an environmental group added their criticism to the fray.

EPA continued to refuse to publicly respond to the allegations.

Documents from the Geneva meeting, attended by the EPA, state that the agency’s “transient cycle” test was already known to grossly underestimate emissions of nitrogen oxide at highway speeds. In written testimony presented at the meeting, the Association of European Vehicle Manufacturers said it had warned as early as 1991 that the engine manufacturers would set their electronic fuel control systems to meet EPA’s requirement for urban NOx emissions — at the expense of on-highway emission targets.

EPA Administrator Carol M. Browner, in announcing record penalties against six diesel engine companies in October, called the electronic controls a “defeat device” that the manufacturers used to cheat on the agency’s certification test.

“We know the EPA had been aware of the use of these defeat devices, and we can confirm that Volvo’s recollection is correct,” said a spokeswoman for Cummins Engine Co. “The EPA knew NOx emissions were significantly higher under steady-state conditions by at least January 1994.”

Margo Oge, director of EPA’s Office of Mobile Sources, told Transport Topics in November that EPA didn’t find out about these problems until 1997.

For the full story, see the Dec. 21 print edition of Transport Topics. Subscribe today.