Study Finds Almost All New Diesels Are Dirty, Automakers Disagree

While it may appear as though the VW dieselgate scandal forced automakers to clean up their diesel vehicles, new testing reveals that most of them continue to emit more toxic NOx than permitted.

The Real Urban Emissions Initiative (TRUE) uses a beam of light to analyze the exhaust plume of a car, Popular Mechanics reports. The rating system has been developed from over 370,000 measurements taken in the United Kingdom, France, and other countries.

During TRUE tests, Euro 3, 4, and 5 diesel vehicles all returned “poor” ratings for NOx levels. Interestingly, almost all new diesel vehicles classified under Euro 6 emission standards received the same rating, meaning they emit more than 180 mg/km of NOx. The only vehicles to receive a more favourable “moderate” rating came from the BMW stable.

According to Greg Archer from Transport & Environment, TRUE testing reveals that the diesel industry has a long way to got before becoming clean.

“The TRUE rating exposes the legacy of Dieselgate – tens of millions of dirty diesels that are still on the roads producing the toxic smog we daily breathe. The rating highlights that nitrogen dioxide pollution, even from most new diesels, is well above those of gasoline cars, legal limits and manufacturers’ claims.”

However, the European Automobile Manufacturers’ Association (ACEA) says the results are misleading, as the newest Euro6d vehicles coming out for the 2019 model year were not tested.

“As all cars tested as part of this TRUE Initiative were pre-Euro 6d vehicles, the fact that they do not meet emissions requirements that only became mandatory after they were put on the market is not surprising,” ACEA secretary general Erik Jonnaer said.