Electric vs petrol — a total cost comparison

Two different cost shapes

The choice between an electric vehicle (EV) and an equivalent petrol vehicle is not just an environmental decision — it is a different cost structure spread across the ownership period. EVs typically cost more to buy and significantly less to run. Petrol vehicles cost less upfront and more across every year of ownership.

Whether the EV wins on total cost depends on the size of the purchase premium, the gap in running costs, and how long you keep the car.

The upfront premium

EVs generally carry a higher purchase price than equivalent petrol models, though the gap has narrowed substantially as battery costs have fallen and model ranges have expanded. The premium varies by segment — small cars often have a larger relative premium, while larger vehicles and SUVs are increasingly close to price parity.

This upfront premium is the figure you need to recover through running cost savings before the EV starts to win on total cost.

Where EVs save money

Energy costs — the largest running cost saving. Electricity per unit of distance is typically 50–80% cheaper than petrol, depending on local electricity and fuel prices. The saving is even larger if you charge primarily at home and especially large with off-peak or solar charging.

Maintenance — EVs have far fewer moving parts than petrol vehicles. There is no oil to change, no spark plugs, no timing belt, no exhaust system, and regenerative braking dramatically reduces brake pad wear. Annual servicing costs for EVs are typically 30–50% lower than equivalent petrol vehicles.

Fuel system maintenance — none. Items like fuel pumps, fuel filters, and emissions equipment do not exist on a battery EV.

Where the comparison gets complicated

Battery degradation — EV batteries lose capacity over time. Modern batteries typically retain 80–90% of capacity after eight to ten years, but the degradation has a real cost: reduced range and a slightly lower resale value. Most manufacturers offer eight-year or longer battery warranties, which limits the worst-case risk.

Resale value — EV residual values have historically been more volatile than petrol residuals, in part because battery technology improves quickly and older EVs can feel dated faster. This is improving as the EV market matures, but it remains a real factor in total cost calculations.

Insurance — EVs sometimes cost more to insure than equivalent petrol vehicles because parts and repairs can be more expensive. The gap varies by insurer and model.

Charging infrastructure — home charging is straightforward if you have off-street parking and a suitable electrical supply. If you rely on public charging, the per-unit cost is higher than home electricity and the convenience is lower. Public charging cost can substantially erode the running cost saving for some drivers.

Calculating the payback period

The payback period is how long it takes for the running cost saving to exceed the upfront premium. The calculation is straightforward in principle:

1. Estimate the upfront premium of the EV over the equivalent petrol vehicle.
2. Estimate the annual running cost saving (fuel + maintenance + any other differences).
3. Divide the premium by the annual saving to get the payback in years.

Typical payback periods today range from three to seven years, depending heavily on annual distance driven, local fuel and electricity prices, and the size of the upfront premium.

When each option wins

EVs win on total cost when:

• You drive significant annual distances (the running cost saving scales with distance).
• You can charge primarily at home, especially off-peak.
• You keep the car for at least five years, usually longer.
• The purchase premium is modest for the segment.

Petrol vehicles win on total cost when:

• You drive low annual distances and the running cost saving cannot recoup the premium.
• You rely heavily on public fast charging.
• You replace the vehicle every two to three years and depreciation dominates total cost.
• The price premium for the EV is large relative to the segment.

Next steps

Use our EV savings calculator to compare a specific EV against an equivalent petrol vehicle and see the payback period. To dig into fuel costs alone, try the fuel cost calculator.