California is home to the nation’s largest car-buying market, rivalling that of many mid-sized countries in the number of cars sold. The size of California’s market gives the state immense influence in setting environmental policy. It wields this influence deftly. California regulators have consistently set air quality standards that outstrip those set by the federal Environmental Protection Agency (EPA). And because of California’s clout, those standards stick. Many states simply adopt California’s standards as their own. So it should come as little surprise then that the Volkswagen Dieselgate scandal begins with the California Air Resources Board (CARB,) the “clean air agency” tasked with defining vehicle emissions standards for the state.
In May 2014, the CARB received a study published by researchers at West Virginia University and the International Council on Clean Transportation (ICCT). The study showed a striking discrepancy between the levels of nitrogen oxide (NOx) emitted by Volkswagen diesel cars tested in labs and those tested on the road. With these facts in tow, the CARB writes to VW requesting an explanation for the anomaly.
Volkswagen engineers would eventually come clean though, explaining how certain VW diesel vehicles would go to market equipped with so-called defeat devices, software that modified engine performance, so as to enable cars to cheat NOx emissions testing. In layman’s terms, the defeat devices allowed certain VW diesel cars to comply with NOx-emissions standards when tested in a lab, but then discharge illegal levels of NOx when on the road – at times, up to 40 times as much pollution as allowed under the U.S. Clean Air Act.
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