Used diesel car prices take a pounding due to surging cost of fuel

If you own a diesel car, look away now.

The soaring cost of fuel since tensions the US and Iran went to war has accelerated the decline in the value of second-hand diesel motors, experts say.

With the cost of a litre of diesel exceeding £2 earlier this month and still teetering dangerously close to the 200p threshold today with tensions still escalated, the price of used oil-burners has taken a significant hit.

Analysis of second-hand prices by Solera cap hpi found that the average value of a diesel car has dropped by 7 per cent in the last 12 months.

While the typical value of a three-year-old diesel motor was already in decline, the firm says the depreciation curve has sharpened noticeably since March, as rising pump prices have put greater pressure on demand.

The cumulative data shows diesel increasingly separating from other fuel types during spring and summer, while hybrid and battery-electric vehicle values have moved in the opposite direction.

Chris Plumb, head of current valuations at Solera cap hpi, says the trajectory of second-hand diesel prices shows 'how quickly buyer sentiment towards running costs can feed through into used car prices'.

He added: 'Diesel at over 195p a litre is difficult for buyers to ignore, particularly when they are comparing it with hybrid and electric alternatives.'

Plumb says this is not only hammering the value of people's cars, but that some used-car dealers are now becoming hesitant about taking them in part exchange to bolster their stock.

'Retailers are seeing that reflected in demand, with diesel stock needing to be particularly desirable or competitively priced,' he explained.

In contrast, second-hand hybrids are proving 'much more resilient,' he says.

'For many buyers hybrid offers lower fuel costs without requiring a change in how they use or refuel their car, and that is supporting demand and values.'

The latest monthly car-pricing data reinforces the notion that your diesel car is becoming increasingly less valuable.

At three years old and 60,000 miles, diesel values have fallen by another 0.6 per cent in October.

This means diesel prices are the weakest-performing of all fuel types for a fifth consecutive month, such has been the impact of surging oil and diesel prices since the war began.

Conventional self-charging hybrids are the strongest-performing vehicles this month, rising by 0.5 per cent, while fully electric cars increased by 0.3 per cent.

There is also evidence that the rising cost of fuel has extended the amount of time diesel cars spend on dealer forecourts.

During September, diesel cars took an average of 41 days to sell, compared with 32 days for hybrids and 33 days for EVs.

Despite the pressure on diesel, Solera cap hpi said the wider used-car market 'remains relatively stable'.

Average values at three years old and 60,000 miles fell by just 0.3 per cent in October, equivalent to a little over £90.

'The figures suggest the fuel crisis is creating an increasingly divided used market, with buyers placing greater weight on day-to-day running costs and hybrids emerging as one of the main beneficiaries,' the company said.

And Carwow says interest in new diesels has also taken a thumping since the cost of fuel has been on the rise.

It says there has been a 33 per cent fall in the volume of requests to dealers for test drives of new diesel models between March and the end of September.

Demand for petrol demonstrations has also dipped by a quarter, it says.

Hybrid enquiries fell by 8 per cent over the same period. 

In contrast, enquiries for EVs rose by 28 per cent, suggesting high fuel costs could be accelerating the shift away from conventional combustion engine cars. 

The latest weekly data shows the decline in diesel interest accelerating, with enquiries down a further 14 per cent in the last week alone compared with the previous week.

Diesel cars account for fewer than one in 20 new car registrations so far in 2026, with the number of diesel models available to UK buyers continuing to shrink.

Iain Reid, consumer editor at Carwow, said: 'Diesel has long been the go-to choice for drivers covering big mileages, thanks to its fuel economy and long-distance range, but soaring fuel prices are changing the maths.

Our data shows a clear shift in buyer interest, with diesel enquiries falling sharply while demand for EVs is going in the opposite direction. 

'The latest generation of electric cars is also addressing some of the traditional barriers around range and charging - with some models now capable of more than 500 miles on a charge and rapid charging adding hundreds of miles in around 20 minutes.

'For drivers who are weighing up their next car, it's worth looking beyond the purchase price and considering the cost of running it. 

'Even when relying on public rapid chargers, our calculations show that an EV can now save hundreds of pounds a year compared with a diesel car.'