CO2 emissions from cars in the EU 14% higher than manufacturers claim - report

Carmakers are under-reporting CO2 emissions from their vehicles, and the gap between official figures and reality is growing, according to calculations by the Council on Clean Transportation (ICCT). ICCT researchers compared the European Environment Agency’s 2022 official car emissions figures against data on the fuel consumption of more 160,000 passenger vehicles. On average, the EEA’s figures – which are based on manufacturers’ measurements – were 14.1% lower than ‘real world’ figures reported by German consumers via the spritmonitor.de online platform. When the ICCT carried out the same comparison in 2018, the figures diverged by only 8%.

Official figures show that fuel consumption and CO2 emission values from EU passenger cars fell by around 7.3% between 2018 and 2022 – but on the road they improved by only 2.3%. The ICCT is calling on the EU to introduce a correction mechanism so that the progress made by car manufacturers on meeting emissions targets can be accurately assessed – ensuring consumers know how much fuel a new car is likely to consume. “If not addressed, this trend will compromise the effectiveness of the EU’s CO2 reduction targets. It will also lead to false consumer expectations about real-world fuel consumption as well as the associated costs and environmental impact,” the ICCT said in a press release. 

Manufacturers determine official CO2 emission values in laboratory tests. Following the dieselgate scandal – when some carmarkers were found to be using software to deliberately cheat these tests – the standard testing procedure was updated. The New European Driving Cycle (NEDC) procedure – which had been giving results up to 33% lower than real-word figures, and largely failed to pick up manufacturers under-reporting emissions – was replaced by the Worldwide harmonized Light vehicles Test Procedure (WLTP) in 2017. Although WLTP results are closer to real-world figures, the ICCT has now found that the gap has grown by 80% since WLTP was introduced five years ago.

The dieselgate scandal broke in 2015 after ICCT analysis showed excessive emissions from Volkswagen vehicles. Volkswagen was found to have been using ‘defeat devices’ – software that manipulates emissions test results. As a result, millions of diesel cars were recalled and VW was fined billions of euros.