ADAC testing finds new diesel cars cleaner than required

- Apr 13, 2020-

ADAC testing finds new diesel cars cleaner than required; Euro 6c and 6d-Temp vehicles well below the permissible NOx limits

In Germany, testing by ADAC (Allgemeine Deutsche Automobil-Club eV) has found that all the Euro 6c and 6d-Temp vehicles that have been measured on the road to date meet much stricter requirements nitrogen oxides (NOx) than required by the EU.

In the test, the cars were not only significantly below the tolerance value of 168 mg/km for diesel cars, which is applied in the road test (RDE method), but also below the current Euro 6 WLTC limit of 80 mg/km.


In December 2018, following the complaints of the cities of Paris, Brussels and Madrid, the European Union Court of Justice annulled the tolerance values for road tests issued by the EU Commission.

The tolerance values—conformity factors (CF)—had been set by the European Commission in order to take into account the technical and statistical inaccuracies of the RDE measurements. Thus, for Euro 6 diesel vehicles, a NOx limit of 80 mg / km was established for the test bench measurements.

However, to ensure that the vehicles can also compete in the RDE procedure, the Commission adopted a compliance factor of 2.1. According to this, new type-approved diesel passenger cars may emit NOx for a transitional period from September 2017 (from September 2019 for newly registered passenger cars) of 168 mg/km instead of 80 mg/km.