Is charging an EV more expensive than filling a petrol car? Costs compared for public fill-ups

Experiment finds petrol fill-up at motorway services station is cheaper than EV charging but home chargers still cheaper per mile

Charging an electric car at a motorway services is up to 28% more expensive than filling an equivalent petrol car, according to a new study.

Consumer title What Car? compared the fuelling costs of four cars - two EVs and two petrol models - and found that when charged at rapid motorway chargers the EVs were between 10% and 28% more expensive, even with petrol at £1.99 per litre.

With the cost of fuel falling since the experiment was carried out, the difference would now be even greater. The study did, however, show that charging at home still offers lower running costs per mile than a combustion engined car, although motoring groups have warned that rise in the energy price cap could hit home chargers in October.

The study took two EVs and their petrol counterparts on a 208-mile trip from Cobham Services, south-west of London, to Skelton Lake Services, near Leeds.

Fuelling the petrol-powered BMW 4 Series Grand Coupe was cheaper than charging its i4 equivalent

The fully electric Peugeot e-208 was pitted against the petrol-powered 208 Puretech 130, while the BMW i4 M50 EV was compared with the closely related 4 Series Gran Coupé M440i petrol.

All four started with a full tank or battery and were refuelled to 100% when they arrived at the destination. The petrol cars were filled at the service station forecourt where petrol was priced at £1.99 per litre while the EVs were topped up at Ionity rapid chargers at a cost of 69p/kWh.

Based on that, the i4 was £5.64 (10.8%) more expensive than its petrol counterpart while the e-208 was £9.07 (28.4%) more.

Paying for convenience

What Car? editor Steve Huntingford said: “When deciding whether an electric car is right for you, it’s important to consider how you would charge it. Even with energy bills going through the roof, an electric car should cost significantly less to run than any petrol alternative if you can top it up at home overnight. However, as our test has shown, lower fuel bills are certainly not a given if you’re relying on the public network, due to the high prices of some companies.

“The Ionity units that we used are some of the most convenient due to their fast charging speeds and the fact that there are usually several at each location, reducing the chances of you having to queue, but unfortunately you pay through the nose for that convenience.”

To ensure a fair comparison, the petrol and electric cars had the same driving mode selected, were driving at the speed limit wherever conditions permitted, and had their climate control systems set to 21C.

Price variations

The experiment also demonstrated the significant differences in costs associated with charging at home or at different public networks.

While the e-208 cost 20p per mile using an Ionity charger and would cost 19p per mile at rival Instavolt, charging on the Gridserve network would cost 14p per mile and at home would cost 8p per mile (based on a domestic energy rate of 28p/kWh). In comparison, based on fuel prices on the day, the petrol 208 cost 13p per mile at an average price of £1.72 per litre and 16p per mile at the highest recorded price of £2.04.

Both BMWs were significantly more expensive. The i4 cost 25p per mile on Ionity and 24/18p on Instavolt and Gridserve respectively. Home charging at 28p/kWh would cost 10p per mile. The petrol 440i, in comparison, cost between 20p and 23p per mile.