Shock new research claims that some of the latest diesel cars emit almost no NOx, despite their condemnation.
Diesel cars have been in decline since the VW dieselgate scandal which shocked the industry back in 2015.
It was found that the carmaker had used defeat devices on cars to trick emissions tests to make cars appear cleaner than they actually were.
Last year the percentage of diesel cars registered in 2018 was over 20 per cent lower than the previous year and this is set to continue.
A common perception among drivers in the UK is that diesel cars are dirty and you should not buy one anymore.
New independent testing has, however, suggested that new diesel cars are actually incredibly clean, despite common belief.
German automobile club (ADAC) conducted on-road RDE (real driving emissions) on a number of petrol and diesel cars to see how clean they were.
Certain Mercedes, Vauxhall, and BMW cars emit almost no nitrogen oxides, significantly less than the legal limit.
Under the Euro 6d Temp emissions rules cars must produce less than 168mg/km of NOx.
During the tests, the Mercedes C-Class C220d actually emitted no NOx at all during the test while the BMW 5 Series 520d Touring emitted just 1mg per kilometre.
Similarly, a 1.6-litre diesel Opel (Vauxhall) Astra also emitted just 1mg/km of nitrogen oxides.
The BMW 520d Steptronic also emitted just 5mg/km, Citroen Berlingo BlueHDI 130 emitted just 7mg/km and the VW Golf 1.6 TDI SCR emit just 14mg/km.
Of the 13 cars tested, the vehicle that produced the most NOx was the Honda Civic 1.6 i-DTEC which emitted 101mg/km, which is still significantly less than the 168mg/km limit.
The results of the cars tested by ADAC
- Audi A8 50 TDI – 15mg/km
- BMW 520d Steptronic – 5mg/km
- BMW 520d Touring – 1mg/km
- BMW X2 xDrive 20d – 23mg/km
- Citroen Berlingo BlueHDI 130 7mg/km
- Honda Civic 1.6 i-DTEC – 101mg/km
- Kia Ceed 1.6 CRDi – 22mg/km
- Mercedes A 180 d – 40mg/km
- Mercedes C 220 d – 0mg/km
- Opel Astra 1.6 D – 1mg/km
- Peugeot 308 SW BlueHDi 180 – 30mg/km
- Volvo XC60 D5 AWD – 56mg/km
- VW Golf 1.6 TDI SCR – 14mg/km
This news will come as reassurance to car manufacturers who have previously tried to defend diesel cars as the new engines are significantly cleaner than those that have come before.
Carmakers have been facing challenges to get cars to meet new real-weld driving emissions limits across the world.
RDE NOx limits are set at 80mg/km (milligrams per kilometre) for diesel cars, and 60mg/km for petrols vehicles to be compliant under the new worldwide harmonized light vehicles test procedure (WLTP) tests.
However, to allow carmakers time to make their cars meet these new standards there is conformity facto of 2.1, which means cars can emit 2.1 times the limit of NOx.
This will be reduced from January 2020 to 1.5 times at 120mg/km of NOx.