A new study by Brussels-based sustainable transport lobbyists Transport & Environment (T&E) claims that diesel cars not only pollute the air but also emit more climate-change emissions (CO2) than petrol cars.

It says a lifecycle analysis of vehicle emissions ‘proves that diesel cars over its lifetime emit 3.65 tonnes of CO2 more than a petrol equivalent’.

T&E says diesel’s higher climate impact is due to several factors:

  • a more energy-intensive refining of the diesel fuel;
  • more materials required in the production of heavier and more complex engines;
  • higher emissions from the bio-diesel blended in the diesel fuel;
  • and longer mileage because fuel is cheaper.

It is claimed that the analysis “debunks carmakers’ claim that diesel cars are needed to meet their climate targets”.

Julia Poliscanova, of T&E, said: “Dieselgate already exposed diesel cars to be the dominant cause of toxic nitrogen dioxide across European cities that is killing 68,000 Europeans annually. Contrary to industry claims, we have learned diesel cars are also worse for the climate than petrol versions and are not needed to meet car CO2 targets. Europe must now look forward and accelerate the transition to clean, electrified vehicles and consign dirty diesels to museums.”

T&E says Europe buys 7 out of 10 diesel cars and vans sold globally while less than 1% of new vehicles sold in the US are diesel and in China, the world’s largest vehicle market, diesel represents less than 2%.

The study claims that distorted national fuel and vehicle taxes mean that diesel fuel is taxed between 10% and 40% less than petrol in most countries.

Julia Poliscanova added: “The legacy of dieselgate are the 37 million grossly polluting diesel cars still on Europe’s roads. While some of them will be taken off German roads, these dirty cars will soon end up in Central and Eastern Europe choking citizens there. We need concerted and coordinated action EU-wide to ensure these cars stop belching toxic fumes for another 10-15 years.

“It is time for the carmakers to take responsibility for their clean up and cash out for the local measures to tackle the urban air pollution crisis they have largely caused.  National vehicle regulators must ensure this happens or the European Commission step in and sort out the mess.”

However, vehicle manufacturers in Europe continue to argue that diesels should continue to play an important role in the automotive industry’s efforts to combat climate change. At last week’s Frankfurt Show, Daimler CEO Dieter Zetsch – in his capacity as chairman of ACEA – Zetsche repeated the claim that diesels perform significantly better than petrol engines on CO2. “The latest generation of diesel vehicles is a very effective lever to achieve climate goals in the near future, because they emit 15-20% less CO2 than equivalent petrol vehicles,” he said.

Link to download study