The value of some used diesel cars has dropped by as much as 26% since the start of this year amid a crackdown on older vehicles.

Second-hand Vauxhall, Audi and BMW diesels have fallen most in price, according to research by the car-buying website Motorway.co.uk. The average used Vauxhall Corsa with a diesel engine has slumped in price from £2,160 to just £1,592 since the start of 2017, a drop of 26%.

The average used diesel car fell in value by 5.7% between the first quarter of 2017 and the third quarter, while used petrol car values rose by 5%.

Motorists are increasingly worried that diesels could become near-worthless in years to come as cities ban the dirtiest polluting vehicles.

Next month the mayor of London, Sadiq Khan, is introducing a £10 emissions surcharge – also known as the toxicity charge, or T-Charge – on top of the existing £11.50 congestion charge that is expected to hit around 10,000 pre-2006 cars, with diesels likely to be most affected.



Other cities in the UK have also debated following London, with plans mooted for parts of Birmingham, Leeds, Nottingham, Derby and Southampton.

Air pollution is believed to cause almost 40,000 premature deaths every year in the UK, with the British government warned this week by the UN that it has violated its obligation to protect people’s lives and health.

Over the past couple of years there has been a constant stream of negative news for diesel vehicle owners, from the VW emissions scandal to new scientific evidence on diesel’s impact on air quality.

But Motorway.co.uk said the data shows that it was not until the second half of this year that diesel values began to slide. “The trends point to this drop accelerating further as the year progresses,” it said.



Major corporate car buyers are already ruling out any further purchases of diesels. Uber, which has about 40,000 London drivers, said this week it will cease using diesel cars in London by the end of 2019 and the vast majority of rides will be in electric or hybrid vehicles by then.

BT, which is one of the biggest UK corporate buyers of cars and vans, said this week it will phase out diesel and petrol-only engines in its fleet of nearly 30,000 vehicles, to be replaced by hybrid or electric-only vehicles.

However, big changes to fuel duty that would have hit diesel drivers have failed to materialise. Earlier this year the prime minister, Theresa May, promised she would not punish drivers of older diesel cars who were encouraged to buy the polluting vehicles under the Labour government.

May said in April that motorists who were urged to switch from petrol to diesel under Tony Blair’s government would be taken into account in future plans.

