The tariff decides everything
If you charge at home on a cheap overnight EV tariff, an electric car is dramatically cheaper per mile than petrol. A typical EV on off-peak home rates costs a few pence per mile for energy; a 40 mpg petrol car at current pump prices costs several times that.
But switch to public rapid charging and the picture changes. Rapid chargers are the most expensive way to fuel an EV — per mile, they can approach petrol territory. That's why we refuse to print one “average cost” figure: it would be wrong for most readers.
Three charging scenarios compared
Every car page on HonestRange computes your monthly running cost against a petrol comparator across three scenarios:
Home off-peak — by far the cheapest. A driveway with a 7 kW home charger and a dedicated EV tariff makes the cost per mile trivial. This is where the headlines about EVs being cheap come from, and they're true — for this scenario.
Home standard rate — still cheaper than petrol for most cars, but the gap narrows substantially. Without an EV tariff you're paying the price-cap standard rate, which is several times the off-peak figure.
Public rapid only — the honest uncomfortable truth. If you rely entirely on public rapids, the savings versus petrol can shrink to the point where an EV may not save you much at all. We will tell you that plainly, because no one else does. Should you buy an EV if you can only charge in public?
Monthly cost: energy + VED + the 2028 road charge
Monthly running cost is your energy bill plus road tax. EVs currently pay standard-rate VED (about £16 a month). From the 2028/29 tax year, a per-mile charge of around 3p is expected to apply on top. At 10,000 miles a year that adds roughly £25 a month.
Our cost model includes both, with a toggle for the 2028 charge so you can see the before-and-after. For the full breakdown, see the 2028 mileage tax explainer.
The home charger payback
A home charger costs in the region of £800–£1,200 installed. But the savings from off-peak rates versus standard rates or public charging can pay that back in under a year for a higher-mileage driver. It's the single biggest lever on EV running cost — bigger than which car you buy.
Our home charging guide covers what you need, what it costs, and how to get a cheap tariff.
When an EV doesn't save you money
We are unusual in being willing to say this. If you have no home charging and rely on public rapids, an EV can end up barely cheaper per mile than a fuel-efficient petrol car. If you drive very low mileage, the savings may not cover a higher purchase price. And if you mainly do short urban trips but occasionally need to tow or do long-distance, range anxiety and charging time become real costs.
Set your real-life mileage and charging situation on any car page and the model gives an honest verdict — including “this may not save you money” when that's what the numbers say.