Average used values of popular diesel models have fallen by 5.7%, according to data from car buying comparison site Motorway.co.uk.

The study, which analysed more than 24,000 used car valuations made since the start of the year, found some models have dropped in value by up to 26%.

Valuations for diesel models were compared to valuations of equivalent petrol models and the data reveals that the average price of the petrol variants has increased by 5%, as demand for ‘dirty diesels’ falls away.

“This year has already been a total shocker for diesel owners. And now that most major manufacturers have launched diesel scrappage schemes, it doesn’t look like it’s about to get any better. Diesel cars are really starting to look like white elephants,” said Alex Buttle, director of Motorway.co.uk.

The following table shows average valuations for some of the UK’s most popular car models, comparing diesel and equivalent petrol variants.