Buyer interest in diesel cars has collapsed as UK pump prices hit records near £2 a litre, with new and used marketplace data pointing the same way.
Auto Express, using figures from sister site Carwow, says dealer enquiries for diesel models — quote and test-drive requests — fell 33% between March and the end of September 2026. Petrol enquiries were down about a quarter over the same stretch. EV enquiries rose 28%, while hybrid interest slipped 8%.
Diesel enquiries alone fell 14% week-on-week in the latest period as prices spiked. Diesels have made up only 4.6% of new car registrations in 2026 so far. Auto Express noted late last year that just 91 diesel models were on UK sale, against 240 a decade earlier.
Used market follows
Autotrader’s September commentary on cars aged up to five years shows diesel’s share of enquiries to dealers halved from 6.6% on 28 August to 3.2% on 27 September. EV enquiry share rose from 20.0% to 25.8%. The average used diesel took 34 days to sell — three days longer than a year earlier and nearly a week longer than the average used EV (28 days).
Ian Plummer, Autotrader’s chief customer officer, said record diesel prices were “strengthening the financial case for electric” and that buyers were “voting with their feet”.
What it costs to fill up
Auto Express cited RAC figures of about £1.99 a litre on average for diesel, with motorway sites around £2.16. Filling a typical 55-litre diesel tank was put at more than £109 — about £30 more than at the start of the US–Iran conflict that pushed oil higher. That tops the previous peak of 199.09p a litre in 2022 after Russia’s invasion of Ukraine.
What Car? put the cost of running a typical diesel 8,000 miles a year at £1,509 at 200p a litre — £435 more than before the war, when diesel averaged 142.38p. At 20,000 miles the rise was £1,087.
RAC policy head Simon Williams said the UK was again exposed to overseas shocks and that only a sustained lower oil price would cut pump prices. The government has kept the temporary 5p fuel duty cut into year-end; further help was flagged for the Autumn Budget.
For taxi and private hire drivers still running diesel, the same prices that hammer household buyers also hit shift costs and residual values on diesel stock. Fewer private buyers wanting diesels can mean softer second-hand prices when fleets renew.