New diesel car emissions spiking at ‘1000 times’ their normal level due to filter cleaning

New diesel cars are still exceeding EU limits for particle emissions, peaking at over 1000 times their normal level, according to campaign group Transport and Environment (T&E).

T&E commissioned independent lab tests into the Nissan Qashqai and Opel Astra, two of the top-selling diesel cars in the market. It found they were between 32% and 115% over the legal limit of 600 billion particles per kilometre when they cleaned their filters.

Filter cleaning, to prevent the diesel particulate filter from clogging, can occur in all driving conditions, including in urban areas. In the tests, the number of particles continued to be higher during urban driving for 30 minutes after the cleaning had ended.

Both models tested were under legal limits for NOx.

According to T&E, a loophole means that the legal limit does not apply when filter cleaning occurs in official testing, meaning that 60-99% of regulated particle emissions from the tested vehicles are ignored.

Total particulate emissions from the Nissan Qashqai and Opel Astra were further increased by 11% to 184% when unregulated ultrafine particles were measured in the lab. 

Transport & Environment (T&E) said lawmakers must accept that ‘diesels are still highly-polluting and should make emissions limits and testing more stringent.’

They also said the European Commission should require authorities to check cars on the road after they have been sold, as the US Environmental Protection Agency does. 

A Nissan spokesman told Reuters: ‘All Nissan vehicles and DPF (diesel particulate filter) devices fitted in our vehicles fully comply with applicable emissions legislation.’

Anna Krajinska, emissions engineer at T&E, said: ‘These tests show that new diesels are still not clean. In fact they are spewing out highly-dangerous levels of particles in our towns and highways everyday.

‘Carmakers are being given an easy ride but people’s lungs are paying for it. Manufacturers should clean up their cars if they want to sell them.’

‘Regulated particles are only half the story. The smallest ultrafine particles are thought to pose a bigger threat yet they’re ignored by official tests. The next Euro pollution standard must close the loopholes and set limits for all pollutants.

‘The endgame is a standard that demands zero emissions from cars on our roads.’