MITtechnologyreview – When Volkswagen debuted the so-called “clean diesel” Jetta TDI sedan and wagon in 2009, it was regarded as something of a breakthrough. The company claimed its new diesel technology would reduce emissions—most notably soot and nitrogen oxides (NOx)—without disrupting the car’s exemplary efficiency or performance.

We now know that unsuspecting owners of some 500,000 VW diesel cars in the United States—and as many as 11 million worldwide—were all the while subjecting themselves and others on the road to extraordinarily high levels of the emissions that cause smog. The company’s CEO apologized after the U.S. Environmental Protection Agency revealed that VW used technology to produce overly forgiving results during smog tests that did not match emissions on the road. Tiếp tục đọc “What the VW Scandal Means for Clean Diesel” →