European diesel car manufacturers may be gaming emissions tests

BBC : According to a recent report by the European Federation for Transport and Environment, emissions tests for diesel cars are not producing accurate results. Although in laboratory tests the cars achieve the 80 mg/km limits on nitrous oxides required by law, cars on the road have been shown to emit five times that amount. The report blames the problem on loopholes in the testing procedure. It says that manufacturers game the system by employing techniques to optimize their cars’ emissions for the tested conditions. Manufacturers, however, deny that any deliberate cheating is involved. Because more than half the cars bought in the European Union in 2014 were diesel, the problem of nitrous oxide pollution is worse in Europe than in the US, where less than 3% of passenger cars run on diesel. Volkswagen has recently admitted to US authorities that it has been gaming emissions tests for its diesel cars.