The decline of diesel: Key questions answered

Diesel cars are common on motorways across the UK - but is this set to change?

Sales of new diesel cars fell dramatically last year amid fears over air pollution - and is has sparked a lot of questions from owners.

Why diesel car sales are dropping - and it could affect the value of second-hand...

Here are some of the key questions on diesel:

I thought drivers were urged to buy diesel cars?

Motorists were encouraged to switch away from petrol under Tony Blair's government as diesel cars generally emit less CO2 because they are more fuel efficient.

Then-chancellor Gordon Brown reduced duty on low-sulphur fuel in 2001, which contributed to an increase in diesel car registrations.

When did it start to go wrong?

Volkswagen sparked outrage in September 2015 when it was found to have fitted defeat device software to 11 million diesel vehicles worldwide.

This allowed the manufacturer to cheat tests for nitrogen oxide pollutants and sparked a rise in concern about air pollution.