How Much Do You Actually Save Switching from Petrol to Electric?

The headline figures around EV savings are everywhere — but they often rely on best-case assumptions that don't reflect reality for most drivers. Here are the real numbers, based on actual UK fuel prices and charging costs, so you can work out what switching would mean for your specific situation.

The honest saving — by mileage

The saving you make depends on three things: how far you drive, what you were paying for petrol, and what you pay to charge at home. Here's the breakdown at different mileage levels, comparing petrol at 169p/litre in a 40MPG car against home charging on Octopus Go (7p/kWh).

*Based on 40MPG petrol at 169p/litre vs 3.5 miles/kWh EV at 7p/kWh (Octopus Go overnight rate)

But that's just fuel — what about everything else?

Fuel is the biggest saving, but it's not the only one. Here's the full picture of how running costs change when you switch to electric.

Servicing — significantly cheaper

A petrol engine has over 2,000 moving parts. An electric motor has around 20. No oil changes, no timing belt, no exhaust system, no clutch. Annual EV servicing typically costs £100–£150 compared to £250–£500 for a petrol equivalent. Over five years that's a saving of £500–£1,750 on servicing alone.

Road tax (VED) — cheaper or free

EVs registered before April 2025 pay zero road tax. Newer EVs pay a flat rate of £195/year — still typically less than a petrol car of equivalent value. If you're buying a used EV registered before April 2025, you pay nothing.

London Congestion Charge — exempt

Electric vehicles are currently exempt from the London Congestion Charge (£15/day). For a driver who commutes into central London regularly, this alone can save £3,000–£4,000 per year. Even occasional London trips add up significantly.

Insurance — currently higher

EV insurance runs 10–25% higher than petrol equivalents. On a typical family car policy, that's roughly an extra £100–£300 per year. This gap is narrowing as more data becomes available and more insurers enter the market — but it's a real cost to factor in.

What does the total saving actually look like?

Taking a typical driver doing 10,000 miles a year, switching from a 40MPG petrol car to an EV charged at home on Octopus Go:

• Fuel saving: +£480/year
• Servicing saving: +£200/year (conservative estimate)
• Road tax saving: +£100–£200/year depending on previous car
• Insurance increase: -£150/year
• Net annual saving: roughly £630–£730 per year

How quickly does the charger pay for itself?

At a net saving of around £680 per year, a home charger costing £1,049 (our Standard pick, the Ohme ePod) pays for itself in around 18 months. After that, every pound of saving is pure gain. Over five years the total saving in running costs is typically £3,000–£3,500 against the charger cost of £1,049.

What about the higher purchase price of the car?

New EVs typically cost more than equivalent petrol cars — often £5,000–£15,000 more. The running cost savings above help close this gap over time, but the full break-even on the car itself typically takes 4–7 years depending on mileage and which models you're comparing. Used EVs, now widely available as early models come off lease, offer much better value — you get all the running cost benefits without the full new-car premium.