Fact check: Petrol cars likely to be less polluting than diesel ones

Among cars made in the past 20 years, petrol is likely to be overall less polluting

The science now tells us that diesel vehicles cause more than four times the pollution than petrol cars.

Sadiq Khan, Mayor of London

Diesel cars have recently become subject to considerable negative publicity thanks to the amount of toxic emissions they produce. Some governments are planning to discourage their use or even ban them from urban areas altogether. Yet some diesel car owners have reacted angrily, arguing they bought the vehicles because they were supposedly the environmentally friendly option.

Diesel was promoted as a more environmentally friendly fuel as part