After the recent Volkswagen fiasco which revealed that their cars emit much more than they should (and claimed), a new study revealed that diesel cars made by Renault, Nissan, Hyundai, Citroen, Fiat, Volvo and many others also emit more.

The Nissan X-Trail fared the worst in the test. Image via Wiki Commons.

Research compiled by Adac, Europe’s largest motoring organisation, found that on their tests, the cars it examined released 10 times more than revealed by existing EU tests. They put cars diesel cars through the EU’s existing lab-based regulatory test (NEDC) and then through a secondary test, developed by the UN (WLTC). The UN test, while also lab based, is thought to better represent real conditions, and will likely be introduced in the EU in 2017.

The problem here is likely the test themselves – the idea of a test. If car manufacturers know what kind of tests their car will be subjected to, then they can optimize results for that specific test – not for the real conditions. This is, while not illegal, still manipulative and highly unethical, but it’s what most car producers do. This is why, when you put the cars through other tests, they don’t fare nearly as well.

But even so, you’d expect an increase somewhere up to 50%, or at the very worst, double – not 10 times or more! According to Adac, here are the biggest polluters, according to Adac.

• Nissan’s X-Trail 1.6 cDi, which produced over 14 times more NOx in the WLTC test. The Guardian also quoted a Nissan spokesperson:

“We can state unequivocally that we are committed to upholding the law and meeting regulations in all markets.” Whoops!

• Renault’s Espace Energy dCi 160, 11 times more, with Renault’s Grand Scenic and Kadjar also among Adac’s top 10 polluters. A spokesperson said:

“The group complies with all regulations and legislation for the markets in which it operates. Its vehicles are not equipped with defeat devices.”

• Jeep’s Renegade 2.0, 10 times more.
• Hyundai’s i20 1.1, Fiat’s 500x 1.6 and Citroen’s DS5 Hybrid4 – all 6 times more.

Reinhard Kolke, head of test and technical affairs at Adac’s state-of-the-art test centre in Bavaria, told the Guardian:

“If all cars complied with [the official EU NOx limit], we would have solved all the worst health effects. Every consumer has the right to expect all manufacturers to do this. But still there are these gross emitters.”

However, unlike the Volkswagen case, Adac reported no sign of cheating in its tests, but only a quarter of the 79 different cars Adac tested came up with similar results. Peter Mock, one of the team at the International Council on Clean Transportation who exposed the VW diesel scandal, expressed upmost confidence in Adac.