The cost of driving 100 miles in the UK depends on your fuel type, your vehicle's efficiency, and current fuel prices. With petrol at 158p per litre, diesel at 191p per litre, and electricity varying between 7p and 24p per kWh, the difference between fuel types is significant -- and growing.
100 Miles: Petrol vs Diesel vs Electric (April 2026)
Here is what 100 miles costs at current UK average pump prices, across different vehicle efficiencies:
| Vehicle Type | Efficiency | Cost per 100 Miles | Cost per Mile |
|---|---|---|---|
| Petrol -- small car | 50 MPG | £14.37 | 14.4p |
| Petrol -- average car | 40 MPG | £17.96 | 18.0p |
| Petrol -- SUV/older car | 30 MPG | £23.94 | 23.9p |
| Petrol -- inefficient | 25 MPG | £28.73 | 28.7p |
| Diesel -- average car | 50 MPG | £17.37 | 17.4p |
| Diesel -- SUV/van | 35 MPG | £24.81 | 24.8p |
| EV -- home charging (standard) | 3.5 mi/kWh | £6.86 | 6.9p |
| EV -- home charging (off-peak tariff) | 3.5 mi/kWh | £2.86 | 2.9p |
| EV -- public rapid charger | 3.5 mi/kWh | £14.29 | 14.3p |
Key takeaway: An electric car charged at home on an off-peak tariff costs £2.86 for 100 miles. That same journey in a 40 MPG petrol saloon costs £17.96, more than six times as much. Public rapid charging wipes out most of the EV advantage and brings 100 miles back to roughly the cost of a 50 MPG petrol.
Current UK Fuel Prices (April 2026)
Fuel prices rose sharply in March 2026. Diesel increased by 25p per litre in three weeks following supply disruption from strikes on Iran. Prices as of April 2026:
- Petrol: ~158p per litre (average UK pump price)
- Diesel: ~191p per litre (spiked from ~166p in February)
- Electricity (home, standard tariff): ~24p per kWh
- Electricity (home, off-peak EV tariff): ~7-12p per kWh
- Electricity (public rapid charger): ~50p per kWh
How the Calculation Works
For petrol and diesel, the formula is straightforward:
Cost = (Distance / MPG) x 4.546 x Price per litre
4.546 converts imperial gallons to litres. So for 100 miles at 40 MPG with petrol at 158p:
(100 / 40) x 4.546 x 1.58 = £17.96
For 100 miles at 50 MPG with diesel at 191p: (100 / 50) x 4.546 x 1.91 = £17.37
For electric vehicles:
Cost = (Distance / Miles per kWh) x Price per kWh
100 miles at 3.5 mi/kWh with electricity at 24p: (100 / 3.5) x 0.24 = £6.86
Fuel Duty Is Rising
The current 5p per litre fuel duty cut ends on 31 August 2026. After that, duty increases in three stages:
- September 2026: +1p per litre
- December 2026: +2p per litre
- March 2027: +2p per litre
By March 2027, fuel duty will be back to pre-cut levels, adding approximately £2.75 to a 55-litre fill-up. From April 2027, fuel duty will rise with inflation every year -- the first increase since 2011. Read our full fuel duty changes guide for more details.
Annual Cost Comparison
The average UK driver covers approximately 7,400 miles per year. Here is the annual fuel cost by vehicle type:
| Vehicle | Annual Fuel Cost | Saving vs Petrol (40 MPG) |
|---|---|---|
| Petrol (40 MPG) | £1,329 | -- |
| Diesel (50 MPG) | £1,285 | £44 |
| EV (home, standard tariff) | £507 | £822 |
| EV (home, off-peak tariff) | £211 | £1,118 |
| EV (public charging only) | £1,057 | £272 |
The financial case for an EV depends almost entirely on whether you can charge at home. If you can, you save £800-1,100 per year on fuel against a 40 MPG petrol. If you rely on public rapid chargers, you save closer to £270 a year, and the saving disappears against more efficient petrol cars.
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