Real-world diesel car emissions

A new study has compared official laboratory-test and on-road nitrogen oxides (NOx) and carbon dioxide (CO₂) emissions for 541 Euro 5 and Euro 6 diesel passenger cars, representing 145 of the most popular European models.

For the Euro 5 diesel cars tested, the actual NOx emissions were on average more than four times the legal limit of 180 mg/km and for Euro 6 cars, the average emission level was 4.5 times the legal limit of 80 mg/km. The difference between individual vehicle models is particularly remarkable, with some Euro 6 diesel cars emitting less NOx than the limit, while others exceed the regulatory limit by a factor of 12. Only 10 per cent of tested Euro 6 vehicles would meet the Euro 6 limits on the road.

Looking at CO₂ performance, the average divergence for both Euro 5 and Euro 6 cars was approximately 30 per cent. The discrepancy among newer vehicles was even higher, with 2015 cars on average emitting 40 per cent more CO₂ and consuming 40 per cent more fuel than advertised.

Source: ICCT, 3 September 2017. http://www.theicct.org/road-tested-sep2017