An official website of the United States government.

We've made some changes to If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.


Detroit Diesel Corporation Diesel Engine Settlement

On October 22, 1998, the Department of Justice and the Environmental Protection Agency announced an $83.4 million total penalty against diesel manufacturers, the largest civil penalty ever for violation of environmental law. Under this settlement, seven major manufacturers of diesel engines will spend more than one billion dollars to resolve claims that they installed computer devices in heavy duty diesel engines which resulted in illegal amounts of air pollution emissions. This settlement will prevent 75 million tons of harmful nitrogen oxide (NOx) emissions nationwide by the year 2025. The companies involved are Caterpillar, Inc., Cummins Engine Company, Detroit Diesel Corporation, Mack Trucks, Inc., Navistar International Transportation Corporation, Renault Vehicules Industriels, s.a., and Volvo Truck Corporation.

The seven companies sold 1.3 million heavy duty diesel engines containing illegal "defeat devices," which allow an engine to pass the EPA emissions test, but then turn off emission controls during highway driving. As a result, these engines emit up to three times the current level for NOx a harmful air pollutant.

"Enforcement Alert: "Clean Air Act Prohibits 'Defeat Devices' in Vehicles, Engines"
(August 1998)

On September 5, 2002, the U.S. District Court for the District of Columbia denied motions by Caterpillar and Detroit Diesel Corporation requesting modifications of the consent decrees that would delay the October 1, 2002 deadline for implementation of tighter emission limits for diesel truck engines manufactured by the companies (U.S. v. Caterpillar, Inc; U.S. v. Detroit Diesel Corporation)