Shropshire Star

Independent tests find nearly 80 per cent of diesels exceed stated emissions

One model produced a shocking 25 times more than the Euro 6 limit for nitrous oxides

Published

Four out of five modern diesel cars emit more nitrogen oxides than official EU limits allow. That’s according to research from consumer group Which?, which has tested 61 cars for emissions since the start of 2017 and found 41 exceed their stated levels.

The official Euro 6 limit is 0.08g of NOx per kilometre. The average car tested by Which? emitted 0.27g/km – nearly 3.5 times the official limit.

The worst culprit was the Subaru Forester, which produced a massive reading of 2.0g/km – 25 times the official EU limit that it met under testing conditions.

Which? says that while its tests were conducted in a laboratory, they are more exhaustive than the official assessments. Vehicles were analysed in their default setting, rather than being switched to their most economical mode, and tests were conducted with the air-conditioning, headlights and radio on.

In addition, Which? tested the cars on a simulated motorway cycle – which the official Euro 6 does not include.

It’s not just Subaru with poor results. All five Renault cars tested were in the top 10, with the Grand Scenic and Captur taking second and third place after the Subaru Forester. Rounding off the top five were the Peugeot 5008 and the Ford Kuga.

Alex Neill, Which? managing director of home products and services, said:
“The current official tests fail to measure the actual level of emissions that cars are producing on our roads.

“Most diesels we assess are producing far more NOx in our tests than official limits allow. The new official tests* should help reduce harmful emissions – but we will continue to penalise any car we find that produces excessive levels of pollutants in our tests.”

(PA)

But it’s not all bad news, and several vehicles produced extremely low readings. BMW’s 2 Series Active Tourer was the cleanest tested, with a reading of just 0.014g/km. The most surprising for Which? was the Mercedes-Benz E-Class, which returned a reading of 0.024g/km.

Testers were so shocked by this that they took the E-Class out of the lab to confirm its reading in real-world conditions, and were impressed to find the readings were very similar.

The Society of Motor Manufacturers and Traders commented on the findings, saying: “The non-official test employed by Which? is very different from the current EU test, so it’s no surprise it delivers different results. Only the official tests accurately compare models on a like-for-like basis.”

Sorry, we are not accepting comments on this article.