Petrol, electric or hybrid: what actually costs less to run?

"Which is cheaper to run: petrol, electric or hybrid?" gets asked as if there's one answer, and there isn't. The honest reply is that it depends on how many miles you do, where you charge or fill up, how long you keep the car, and how much you paid for it in the first place. Fuel is the headline, but it's only one line on the bill. Once you add tax, servicing, insurance and depreciation, the ranking can shuffle completely. Here's how the three actually compare, and how to work out which one wins for the way you drive.

Fuel and energy: the headline number

On cost-per-mile for energy alone, there's a clear pecking order most of the time, but the size of the gap swings wildly depending on how you top up:

• Electric, charged at home: the cheapest by a distance, especially on an off-peak overnight tariff. Home electricity turns into pennies per mile in a way petrol simply can't match.
• Electric, charged on public rapid chargers: a completely different story. Rapid-charging prices can push the per-mile cost up to roughly petrol levels, sometimes past them. An EV that never sees a home charger loses much of its running-cost advantage.
• Hybrid: better than a plain petrol, particularly in town where the electric motor does the low-speed work, but the saving is real rather than dramatic. A plug-in hybrid can be excellent on short trips if you actually charge it, and no better than petrol if you don't.
• Petrol: the baseline everything else is measured against. Predictable, familiar, and the same price whether you fill up at home or 200 miles away.

Because the numbers depend so heavily on your own mpg, electricity rate and mileage, a rule of thumb is nearly useless here; you want your own figures. Our fuel cost calculator lets you plug in your mileage and prices and compare petrol, diesel and electric per mile, which is far more honest than any generic "EVs are cheaper" claim.

Tax, and the end of the EV freebie

For years the electric car's trump card was zero road tax. That's gone. Since April 2025, electric cars pay Vehicle Excise Duty like everything else (a token first-year rate and then the standard annual rate), and a pricier EV that cost over £40,000 new also gets caught by the expensive-car supplement in years two to six. It's still often a modest bill next to a big petrol engine, but the "free to tax" line no longer holds. You can check what any car actually costs to tax with our car tax calculator, and the car tax guide explains why three different systems are running side by side.

Servicing and repairs

This is where pure electric quietly pulls ahead. No oil changes, no cambelt, no clutch, far fewer moving parts, and regenerative braking that means the brake pads and discs last much longer than on a petrol car. Routine servicing is usually cheaper as a result. The counterweight is the battery, the single most expensive component on the car, but on a used EV that's really a question of warranty and history rather than regular maintenance.

Hybrids sit in an awkward middle. They carry both a combustion engine and an electric system, so on paper there's more that could need attention. In practice the mainstream hybrids have proven reliable, but you're servicing two powertrains rather than one, and that isn't free. A plain petrol is the most familiar and the easiest to get fixed anywhere, which counts for something if you keep cars a long time or live away from a dealer network.

Depreciation: the cost nobody feels until they sell

The biggest running cost on almost any car isn't fuel: it's depreciation, the value that quietly evaporates while the car sits on your drive. And here the picture is genuinely mixed. Electric cars have depreciated hard over the last couple of years as new-car prices fell and the used market filled up, which is painful if you buy new but a gift if you're buying used. Hybrids from established makers have generally held their value well. Petrol cars are the known quantity, depreciating along familiar curves.

If you buy a used EV that's already taken its steepest drop, you can sidestep the worst of it entirely. To get a feel for how much a given car is likely to lose, our car depreciation calculator projects the value forward over the years you plan to keep it.

So which one actually wins?

It comes down to your circumstances more than the technology:

• High mileage, can charge at home: electric, comfortably. The per-mile saving compounds fast, and lower servicing helps.
• Lots of town driving, shorter trips: a hybrid or a genuinely plugged-in plug-in hybrid makes a lot of sense, and sidesteps range worries.
• Low mileage, no home charger, or long unpredictable trips: a petrol car is often the cheapest and least stressful overall, whatever the per-mile charts say.
• Buying used and cost-focused: a used EV that's already depreciated can be the sweet spot (cheap to buy, cheap per mile at home, cheap to service) provided the battery health checks out.

Whatever you pick, check the car first

Running-cost sums only matter if the car itself is sound. That's especially true of an electrified car, where the battery is most of the value and most of the risk: an EV or hybrid with a tired battery or a patchy history can wipe out every penny you hoped to save on fuel. Our used electric car guide walks through what to look for, and before you buy anything it's worth a free MOT check and a full history report to confirm the mileage trail, MOT record and tax position. The cheapest car to run is the one you bought with your eyes open.