Back in 1990, the EPA’s Clean Air Act restricted emissions from diesel engines. Meeting clean air standards was very difficult, so for many years the diesel cars that were sold in Europe didn’t come to America. Gradually, German automakers, who were strong in diesel technology, brought diesels that were in compliance with EPA standards to the U.S.
Consumers could now experience torque and range — diesel’s key virtues — without worrying about the claims that the environment would be compromised by the emissions from these engines.
We all know what has happened. Volkswagen used software, known as a defeat device, in 2.0-liter, four-cylinder Volkswagen and Audi diesel cars from model years 2009-2015 to circumvent EPA emissions standards for certain air pollutants.