The shift comes as diesel prices have exceeded £2 per litre for the first time, putting pressure on motorists and second-hand car dealers. Buyers are increasingly considering running costs when choosing a vehicle, a change that is reflected in both resale values and the time cars spend on forecourts.
Rising Diesel Costs Put Pressure on Second-Hand Car Values
Figures from Solera Cap HPI show that the average value of a three-year-old diesel car with 30,000 miles has fallen by 6.9% over the past 12 months, according to Fleet News. The decline has become more pronounced since March, when rising fuel costs began placing greater pressure on demand.
Diesel prices exceeded £2 per litre earlier in October, before falling back to an average of 199.9p. Car Dealer Magazine reported that diesel was trading at around 195p per litre, approximately 23p more than petrol, making a typical fill-up cost about £105.
The effect on vehicle valuations has continued into October. At three years old and 60,000 miles, diesel cars lost another 0.6% of their value, making them the weakest-performing fuel type for five consecutive months.
Chris Plumb, head of current valuations at Solera Cap HPI, said the figures demonstrated how quickly concerns about running costs could influence second-hand prices. “Diesel at around 195p a litre is difficult for buyers to ignore, particularly when they are comparing it with hybrid and electric alternatives,” he explained.
Dealers are also experiencing slower sales. During September, used diesel vehicles took an average of 41 days to sell, compared with 32 days for hybrids and 33 days for battery-electric cars.
Despite these differences, the wider used-car market has remained relatively stable. Average values for three-year-old vehicles with 60,000 miles declined by just 0.3% in October, equivalent to slightly more than £90.
Hybrid and Electric Cars Attract Growing Buyer Interest
While diesel values have weakened, alternative powertrains have performed differently. Conventional self-charging hybrids recorded a 0.5% increase in value during October, while battery-electric vehicles gained 0.3%.
Plumb said hybrids were benefiting from buyers seeking lower fuel costs without changing their usual refuelling habits. Their relative stability contrasts with the continued depreciation affecting diesel models.
According to This Is Money, figures from Carwow also indicate a shift in demand for new vehicles. Requests to dealers for diesel test drives fell by 33% between March and the end of September, while petrol enquiries declined by 25%. Hybrid enquiries decreased by 8% over the same period. Electric vehicle enquiries, by contrast, increased by 28%.
The latest weekly figures showed diesel enquiries falling by a further 14% compared with the previous week. Diesel vehicles now account for fewer than one in 20 new UK car registrations in 2026, while the range of available models continues to shrink.
Iain Reid, consumer editor at Carwow, noted that diesel had traditionally appealed to high-mileage drivers because of its fuel economy and long-distance range. He said newer electric vehicles were addressing concerns about range and charging, with some models offering more than 500 miles per charge. Carwow’s calculations also suggest that electric vehicles can save drivers hundreds of pounds annually compared with diesel, even when public rapid chargers are used.
