Hardware retrofitting of manipulated diesel cars pushes up CO2 emissions – automobile club

Retrofitting manipulated diesel cars with hardware that reduces their output of harmful nitrogen oxide (NOx) can greatly increase a vehicle’s fuel consumption and, consequently, its CO2 emissions, a long-term trial by Germany’s biggest automobile club ADAC has found. The ADAC tested three different hardware retrofitting systems in a trial aimed at identifying the effects after 50,000 kilometres travelled. While NOx emissions were reduced across the board by up to 70 percent under warm weather conditions, carbon emissions in all three cases rose more than the 6 percent increase allowed under political guidelines for retrofitting. Additional carbon emissions stood between 7 and 13 percent, depending on the system and car model. Fuel consumption rose by 9 percent on average, the ADAC said.

Nitrogen oxide emissions by diesel cars were at the centre of the so-called dieselgate scandal, in which it was revealed that most German carmakers as well as competitors from abroad manipulated their cars’ engines to show lower emissions levels on the test stand than in real life. Many German cities have introduced or are poised to introduce partial driving bans for diesel cars to comply with EU air pollution regulations. Many experts say hardware retrofits are the only option to cut NOx emissions sufficiently, but carmakers continue to oppose this measure because of high costs.