VW scandal: 3.6m European vehicles need major changes
Mercedes-Benz, Honda, Mazda and Mitsubishi have joined the growing list of manufacturers whose diesel cars are known to emit significantly more pollution on the road than in regulatory tests, according to data obtained by the Guardian.
Wide range of cars emit more pollution in realistic driving tests, data shows
In more realistic on-road tests, some Honda models emitted six times the regulatory limit of NOx pollution while some unnamed 4x4 models had 20 times the NOx limit coming out of their exhaust pipes.
“The issue is a systemic one” across the industry, said Nick Molden, whose company Emissions Analytics tested the cars. The Guardian revealed last week that diesel cars from Renault, Nissan, Hyundai, Citroen, Fiat, Volvo and Jeep all pumped out significantly more NOx in more realistic driving conditions. NOx pollution is at illegal levels in many parts of the UK and is believed to have caused many thousands of premature deaths and billions of pounds in health costs.
All the diesel cars passed the EU’s official lab-based regulatory test (called NEDC), but the test has failed to cut air pollution as governments intended because carmakers designed vehicles that perform better in the lab than on the road. There is no evidence of illegal activity, such as the “defeat devices” used by Volkswagen.
The new data is from Emissions Analytics’ on-the-road testing programme, which is carefully controlled and closely matches the real-world test the European commission wants to introduce. The company tested both Euro 6 models, the newest and strictest standard, and earlier Euro 5 models. Data showed that:
Mercedes-Benz’s diesel cars produced an average of 0.406g/km of NOx on the road, at least 2.2 times more than the official Euro 5 level and five times higher than the Euro 6 level. A spokesman for Mercedes-Benz said: “Since real-world driving conditions do not generally reflect those in the laboratory, the consumption figures may differ from the standardised figures.”
Honda’s diesel cars emitted 0.484g/km of NOx on average, between 2.6 and six times the official levels. A spokesman for Honda said: “Honda tests vehicles in accordance with European legislation.”
Mazda’s diesel cars had average NOx emissions of 0.293g/km in the real world, between 1.6 and 3.6 times the NEDC test levels. One Euro 6 model, the Mazda 6 2.2L 5DR, produced three times the official NOx emissions. A spokesman for Mazda said: “In compliance with the law, Mazda works hard to ensure that every petrol and diesel engine it makes fully complies with the regulations.”
Mitsubishi diesel cars produced an average of 0.274g/km of NOx, between 1.5 and 3.4 higher than in the lab. “The NEDC was never intended to represent real-world driving,” said a spokesman for Mitsubishi.
The Emissions Analytics data seen by the Guardian also found Citroen, VW and Audi NOx emissions to be higher on the road than in the EU lab test.