Introduction
Rising fuel costs are changing how buyers assess used cars. In the UK, Autotrader reported a 40% year-on-year increase in demand for used electric cars in September 2026, while demand for diesel models fell 19.2%.
But stronger demand does not automatically mean better resale value. This guide examines how demand, supply and asking prices are changing across fuel types, and how buyers can compare running costs before choosing a used car.
1. What the Latest Used Car Market Data Actually Shows
The UK used car market showed contrasting trends in September 2026. According to Autotrader's Retail Price Index, the average used-car asking price fell 1% year on year to £17,299. However, used EV asking prices rose 2.8% to £25,091, while petrol and diesel prices fell by 1% and 0.8%, respectively.
UK Used Car Market by Fuel Type
| Fuel type | Demand change | Supply change | Average asking price | Price change |
| Electric | +40.0% | +26.0% | £25,091 | +2.8% |
| Petrol | −5.8% | −5.7% | £14,625 | −1.0% |
| Diesel | −19.2% | −6.8% | £13,924 | −0.8% |
Source: Autotrader UK, September 2026 data; year-on-year changes. Prices are average asking prices, not confirmed sale prices.
The figures reveal different supply-demand patterns across fuel types. EV demand grew faster than supply, alongside rising asking prices. Diesel demand declined more sharply than supply, while petrol demand and supply fell at similar rates. These patterns suggest that market conditions vary by fuel type, although the data alone cannot establish how much rising fuel costs contributed to the changes.
Vehicle age also affects market trends. Autotrader reported that asking prices for cars aged 10–15 years rose 5.6% year on year, while those for cars under one year old fell 2.7%. This reinforces an important point: used-car values reflect more than fuel type alone. Age, condition, mileage and model-specific demand also matter, and changes in average asking prices do not directly measure individual vehicle depreciation.
2. Why Petrol, Diesel and Electric Cars Are Moving in Different Directions
Rising fuel prices can change how buyers compare the cost of running different vehicles. If more buyers favour fuel-efficient models or used EVs, demand may grow faster than supply, putting upward pressure on asking prices. The opposite can happen when demand weakens relative to available stock. However, the effect on resale values is neither automatic nor uniform.
Petrol cars may remain attractive because of their lower upfront cost and familiar refuelling options. Models with strong real-world fuel economy could become more competitive as petrol prices rise.
Diesel cars can still suit drivers who cover long distances. However, weaker demand in some segments, emissions restrictions and maintenance costs may put pressure on certain models.
Used electric cars may attract buyers seeking alternatives to petrol and diesel. Yet increased supply, competition from newer EVs, battery health and concerns about driving range can limit price gains even when demand rises.
3. How to Calculate the Real Cost of Owning a Used Car
Fuel economy and electricity prices affect the cost of running a used car. To compare a petrol car with a used EV, start by estimating their annual energy costs based on your mileage, vehicle efficiency and the prices you expect to pay.
Annual petrol cost = annual miles ÷ UK mpg × 4.546 × petrol price per litre
For an EV:
Annual electricity cost = annual miles × energy use per mile × electricity price per kWh
For example, assume you drive 7,500 miles a year, a petrol car averages 40 mpg, and a used EV consumes 0.29 kWh per mile. Using illustrative prices of £1.50 per litre for petrol and £0.30 per kWh for electricity:
- Petrol car: approximately £1,278 per year.
- Electric car: approximately £653 per year.
- Estimated annual energy cost difference: around £625 in favour of the EV.
These figures are illustrative, not current UK average prices. Actual costs depend on driving conditions, vehicle efficiency, charging losses and your electricity tariff. Home charging may be cheaper than public charging, while frequent use of public rapid chargers can increase costs.
Lower energy costs do not necessarily mean lower overall ownership costs. To compare the vehicles fairly, also consider purchase price, insurance, maintenance and potential resale value over the period you plan to own the car.
4. What China's Used Car Market Can Tell International Buyers
China offers a useful perspective on the expanding market for used electric and other new energy vehicles. According to the China Automobile Dealers Association (CADA), new energy vehicles accounted for 7.9% of used-car transactions in 2025, representing around 1.6 million vehicles.
For international buyers and vehicle traders, this growth highlights the importance of assessing battery health, warranty coverage, vehicle condition and after-sales support when evaluating used EVs for resale or export. These factors can influence a vehicle’s marketability and potential resale value across different markets.
However, China’s market trends do not directly predict UK resale values. Local demand, import costs, regulations, vehicle specifications and access to repairs can all affect the value of an imported vehicle.
5. Which Used Cars Offer Better Value as Fuel Costs Rise?
Annual mileage and purchase price are useful starting points when comparing used cars.
- Mostly city driving: A used EV may suit short daily journeys if charging is convenient. A small petrol car is worth considering if you need a lower upfront cost or lack reliable charging access.
- Frequent long journeys: Compare real-world fuel economy, driving range and refuelling or charging convenience along your usual routes.
- High annual mileage: Compare real-world energy costs carefully, as even small differences in cost per mile can add up over time.
- Low annual mileage: A lower-priced petrol car may cost less overall if an EV’s higher purchase price outweighs its potential energy savings.
Use your typical journeys and budget to narrow the options before comparing individual vehicles.
6. How to Buy a Used Car Without Overpaying
Compare similar vehicles by age, mileage, specification and condition to see whether an asking price is competitive. Check the vehicle’s service records and history, along with its MOT test history. Look for mileage discrepancies, recurring defects and upcoming repairs, and arrange an independent inspection where appropriate.
For a used EV, check battery health, remaining warranty and real-world range. Battery condition and potential repair costs can affect both day-to-day use and future resale prospects.
Use the inspection findings and estimated repair costs to support your offer.
7. Frequently Asked Questions
Q1: Do rising fuel prices affect used car values?
They can shift demand towards more fuel-efficient vehicles, but resale values also depend on supply, vehicle condition and model-specific demand.
Q2: Are used electric cars cheaper to run than petrol cars?
Often, especially with affordable home charging. Actual savings depend on energy prices, mileage and vehicle efficiency.
Q3: Will diesel cars lose value as fuel prices rise?
Not necessarily. Long-distance drivers may still value diesel efficiency, while emissions restrictions and maintenance costs can affect demand for certain models.
Q4: How can I tell whether a used car offers good value?
Compare its purchase price, expected running and maintenance costs, and potential resale value over your planned ownership period.
Q5: What should I check before buying a used electric car?
Check battery health, remaining warranty, real-world range and service history. Also consider local charging access and repair support.
References
- Autotrader UK. “Used EV Demand Surges 40% as Rising Fuel Costs Reshape Used Car Market.” 9 October 2026.
- China Automobile Dealers Association. Includes full-year 2025 used new energy vehicle transaction figures.
- MoneyHelper. “Costs of Buying and Running a Car.” Guidance on insurance, vehicle tax, fuel, servicing and repairs.