Petrol vs Electric — What's the True Cost Per Mile in 2026?
With petrol at 156p/litre and electricity at 24p/kWh, the economics of electric vs petrol driving have never been more interesting. But the headline numbers hide a lot of nuance — particularly around how and where you charge, and what you're comparing against.
This guide cuts through the noise with real-world numbers for UK drivers in 2026.
⚡ The short answer
If you charge at home: Electric is significantly cheaper — typically 40-60% less per mile than petrol.
If you charge mainly at public rapid chargers: The economics are much closer and can sometimes favour petrol.
If you're deciding whether to switch: The fuel saving alone rarely justifies the switch — but combined with lower maintenance costs, the total picture often does.
Cost per mile — the real numbers
| Scenario | Cost per mile | Annual cost (12,000 miles) |
|---|---|---|
| ⚡ EV — Octopus Go off-peak (7p/kWh) | ~2p | ~£240 |
| ⚡ EV — home charging (24p/kWh) | ~7p | ~£840 |
| ⛽ Petrol — efficient (45 MPG) | ~8.7p | ~£1,040 |
| ⛽ Petrol — average (38 MPG) | ~10.3p | ~£1,240 |
| 🛢️ Diesel — efficient (55 MPG) | ~8.6p | ~£1,035 |
| ⚡ EV — mixed public/home charging | ~11p | ~£1,320 |
| ⛽ Petrol — heavy (28 MPG SUV) | ~14p | ~£1,680 |
| ⚡ EV — rapid charging only (75p/kWh) | ~21p | ~£2,520 |
It depends entirely on how you charge
The single biggest factor in the petrol vs electric calculation isn't the car — it's where you charge. Here's how the same EV looks in different scenarios:
🏠 Home charger + off-peak tariff
The best case scenario. Charging overnight on Octopus Go at 7p/kWh costs around £4 for a full 60kWh battery — enough for 200+ miles. Cost per mile: ~2p.
✓ Significantly cheaper than petrol🏠 Home charger + standard tariff
At 24p/kWh, a full charge costs ~£14.40. Still cheaper than petrol for most drivers, especially vs larger petrol cars. Cost per mile: ~7p.
✓ Cheaper than petrol🔌 Mixed home and public charging
Many EV drivers charge at home most of the time and use public chargers for longer trips. The blended cost depends on the mix — typically 10-13p per mile.
≈ Similar to average petrol⚡ Rapid charging only
No home charger, relying on public rapid chargers at 70-85p/kWh. At these rates, an EV can cost more per mile than a petrol car. Cost per mile: ~20-24p.
✗ More expensive than petrolThe home charger is the key: Without one, the economics of EV ownership are much less compelling. If you can't charge at home (flat, no driveway), factor this carefully into your decision.
Beyond fuel — the full running cost picture
Fuel is just one part of the running cost equation. EVs have meaningful advantages elsewhere:
| Cost category | Petrol car | Electric car |
|---|---|---|
| Fuel/energy (12,000 miles) | £1,040-1,680 | £240-1,320 |
| Servicing (annual) | £200-400 | £100-200 (no oil, fewer brakes) |
| Road tax (VED) | £190-620 | £0 (until April 2025, now £10/year) |
| Insurance | £500-1,200 | £600-1,400 (often slightly higher) |
| Tyres | £200-400 | £250-500 (heavier cars wear tyres faster) |
| Depreciation | Varies | Varies (improving as market matures) |
The servicing saving is real and significant — no oil changes, fewer brake replacements (regenerative braking reduces brake wear dramatically), and fewer moving parts overall means lower maintenance costs over time.
The CO2 argument
An EV produces zero tailpipe emissions, but the electricity it uses has a carbon footprint. The UK grid currently averages around 233g CO2/kWh — giving a typical EV journey a carbon intensity of around 60-70g CO2/mile.
A petrol car averaging 40 MPG produces around 180-200g CO2/mile — roughly three times more. As the UK grid gets cleaner (more renewables, less gas), EV emissions will continue to fall while petrol cars stay the same.
Should you switch? Key questions to ask
Can you charge at home? If yes, the economics strongly favour switching. If no, calculate carefully.
How many miles do you do? Higher mileage drivers save more — the fuel saving compounds quickly.
What's your current car? Switching from a large petrol SUV to a mid-range EV charged at home could save £800-1,200/year in fuel alone.
Do you do regular long motorway journeys? EVs are less convenient for frequent long trips without home charging — factor in charge stop time.
Calculate your own petrol vs electric cost — free