Diesel cars' emissions far higher on road than in lab, tests show

UK inquiry after Volkswagen scandal finds much higher nitrogen oxide levels than when vehicles are tested in laboratory

Diesel cars are producing many times more health-damaging pollutants than claimed by laboratory tests, with some emitting up to 12 times the EU maximum when tested on the road, according to a government investigation undertaken following the Volkswagen scandal.

A Department for Transport (DfT) study of cars made by manufacturers such as Ford, Renault and Vauxhall found there was a vast difference in nitrogen oxide emissions measured in the laboratory and under normal driving conditions.