92% of new diesels rated “poor polluters” by new study

92% of new diesels rated “poor polluters” by new study

150 150 Mike Boorman

The latest results from The Real Urban Emissions (TRUE) Initiative send a strong reminder that even modern vehicles are polluting the air to dangerous levels.

Euro 6 vehicles from 2017 returned NOx readings significantly beyond the lab-defined limits, with the large majority of diesels emitting more than triple the Euro 6 limits. 92% of Euro 6 diesels were rated as “poor” by TRUE’s NOx-emission standards, while the remaining 8% attained a “moderate” rating.

Over 100,000 vehicles across London were scanned with special infrared and ultraviolet beams to measure their ‘real’ NOx output in everyday conditions. The worst offenders were Euro 5 diesel black cabs, which actually produced over 50% more NOx than the earlier Euro 3 and Euro 4 models. This made a Euro 5 black cab 30-times more polluting than the cleanest petrol cars of the same age.


Our reaction…

These results are yet more proof of the massive difference between what a vehicle may emit in a controlled environment versus what is actually happening out there on our streets. It’s important to point out that the TRUE study doesn’t suggest any fraudulent activity from vehicle manufacturers, and we don’t think the results should be used to rate diesel as an inherently “worse” polluter than petrol in all cases, but the point remains that modern vehicles made to supposedly “green” standards are polluting significantly more than was intended. While no one expected performance in the lab to be equal to the roads, the disparity is deeply worrying.

Modern standards not fit for purpose

This poses a headache for politicians who are introducing new emissions zones based upon some of the Euro standards deemed unfit for purpose by the independent study above. Birmingham and London will introduce new zones in 2019 where vehicles rated as “poor” will be exempt from the charge. Given the results of this independent study, and given the fact that even worse polluters will still be allowed to carry on driving as long as they pay for the right to do so; are emissions zones really a valid solution?

New standards long overdue

To give some credit to the EU, the Euro 6 testing standards on diesels have been tightened up significantly. The NEDC lab test that was previously used to uphold the Euro NOx limits has been replaced by the Worldwide Harmonised Light Vehicle Test Procedure (WLTP); a lab test that incorporates significantly more ‘real’ driving data. Vehicles are now also subject to an intensive journey of up to two hours in a range of different driving conditions (the Real Driving Emissions Test (RDE)).

It’s time for a rethink on policy

Euro 6 vehicles subject to the new testing were not on the roads at the time of the TRUE London study, so it will be interesting to see how these new vehicles fare in the next TRUE study later this year. Even if the latest batch of vehicles succeed in keeping NOx emissions down to the intended levels, there is no getting away from the fact that the majority of cars on the road alongside them will be polluting the atmosphere beyond safe levels, and they will still represent the majority for decades to come. Simply charging motorists for the privilege will not solve this problem any time soon, and nor will the promise of electric cars in the distant future.

For the sake of our planet, it’s time for politicians to think more laterally about the emissions problem.

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