Can an EV pay
for itself? Almost.

The pitch is seductive: ditch the petrol car, plug in overnight at a few pence a unit, and let what you used to spend on fuel quietly cover the monthly payment on a brand-new electric SUV. A free car, in effect. So we took a real lease deal, a real tariff and a real household, and asked whether the books actually balance.

Our family is deliberately ordinary: a three-bed detached house, no solar panels and no home battery, an outgoing petrol car covering 5,000 miles a year at 30mpg — and that old car is now due for its tax, an MOT and a fresh set of tyres. The replacement is the Vauxhall Frontera Electric GS 54kWh on the same £138.55 lease we covered last week, charged at home on Intelligent Octopus Go, with the washing machine, tumble dryer and dishwasher shifted into the cheap overnight window.

What happens to the electricity bill

This is the part that surprises people. On Intelligent Octopus Go, the guaranteed overnight window (roughly 11:30pm–5:30am) currently bills at about 7p per kWh, and the car charges itself in that window automatically. Daytime sits at a more familiar ~27p, with a standing charge near 57p a day.

A three-bed detached with no solar gets through around 4,000 kWh of household electricity a year. The trick is to push as much of it as possible into that 7p window. Set the washing machine, tumble dryer and dishwasher to run overnight and you move roughly 860 kWh a year — about £172 of electricity — from the 27p day rate down to 7p. Charging the Frontera for 5,000 miles adds another ~1,430 kWh, all at 7p.

Two things stand out. The car itself adds only about £100 a year — roughly £8 a month — to the electricity bill. And shifting the laundry and dishes overnight quietly knocks about £172 a year off the household bill on top — a saving you only unlock because going electric put you on this tariff in the first place.

Petrol versus electric: the real running costs

The outgoing petrol car burns about 758 litres to cover 5,000 miles at 30mpg. At a mid-2026 pump price of roughly 155.5p a litre, that's £1,178 a year in fuel. On top sits its road tax, an annual MOT, and — being an older car — a set of tyres due about now (around £360 fitted, spread over our two-year window). The brand-new Frontera needs none of these: tax is bundled into the lease, it's MOT-exempt until it turns three, and at just 10,000 total miles it rolls through the period on its original tyres.

So before we even touch the laundry, switching frees up about £1,508 a year, or £126 a month, in fuel, tax, MOT and tyres. Add the £172-a-year load-shifting saving and the total benefit of going electric is roughly £1,680 a year — £140 a month. The question is whether that pot now swallows the lease.

Do the books balance?

Now it gets interesting. That £140-a-month saving actually edges past the £138.55 headline lease payment. On a month-to-month basis, the money you stop spending on petrol, tax, MOT, tyres and daytime electricity more than covers the cost of the car. The headline payment, in effect, pays for itself.

The one thing the savings don't fully absorb is the upfront money — the £1,246.95 initial rental plus £299 in fees. Spread across the two years, that lifts the true cost to about £197 a month, and the savings cover roughly 71% of it, leaving around £57 a month. So the genuinely accurate headline is this: the running savings cover the monthly payment in full — only the deposit stops it being a completely free car.

And it only gets better with miles

These figures are for a low-mileage family. Every extra mile widens the gap, because petrol costs about 23.6p a mile here versus just 2p a mile on the 7p overnight rate. Cover the all-in cost — deposit and all — and you reach a genuinely free car at around 10,000 miles a year. The catch: this particular deal is capped at 5,000 miles, so chasing that would mean a higher-allowance (and slightly pricier) contract.

The catch the old pitch forgets

The classic "free EV" argument leans on scrapping road tax. That loophole has closed: since April 2025, electric cars do pay VED — £10 in year one, then the standard £195 a year after that, the same as a petrol car. On a lease it's bundled into the monthly price, so you don't see it, but the saving versus your old car is now essentially nil rather than a bonus. From April 2028 a pay-per-mile scheme (3p a mile for EVs) is due to chip away further.