Charging an electric car can be 28% more expensive than filling up with petrol, experts revealed.
What Car? drove two electric cars and their petrol equivalents from London to Leeds to see if petrol is still cheaper than electricity.
Topping up at motorway services, the 208-mile journey was up to 28% more expensive using an electric car.
The difference would be even bigger now, because at the time of the test petrol prices were close to an all-time high.
If you can mostly charge at home overnight, however, electric cars remain cheaper to run.
The fully electric Peugeot e-208 went head to head with the petrol-powered 208 Puretech 130.
Meanwhile, the larger BMW i4 M50 electric car was compared with the closely related 4 Series Gran Coupé M440i petrol.
All of the vehicles started with a full battery or tank of fuel.
Then on arrival, they were plugged in or brimmed to find out how much the journey had cost.
The e-208 and i4 working out £9.07 (28.4%) and £5.64 (10.8%) more expensive than their petrol equivalents, respectively.
The differences would actually be even bigger now, because at the time of the test petrol prices were close to an all-time high; What Car? paid £1.99 per litre.
By contrast, the 69p/kWh rate to access the Ionity rapid chargers that were used to charge the electric vehicles has remained the same since 2020.
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."
In each case, the petrol and electric cars had the same driving mode selected. Plus, they were all driven at the speed limit where conditions permitted, with their climate control systems set to 21C.
Anyone who buys a new BMW electric car gets a 12-month subscription to BMW Charging, which means they initially pay only 26p/kWh to use Ionity chargers, with the full 69p/kWh rate only kicking in from the second year.
Last month The Mirror reported an electric car owner has to charge his vehicle through his first-floor window after being told to remove a charging point he installed himself.
Joe Keating, who rents a flat in Falinge, Rochdale bought an electric BMW in an effort to cut carbon emissions and fuel costs and installed a charging point next to his parking space.
Not long after, however, he received a letter from managing agents Stevenson Whyte telling him to remove the power-point - a move which he felt was “heavy-handed” and showed a reluctance to support the “green agenda”.