theres different ways and different data to work out the cost which is where alot of costing falls over and gets annoying/confusing.

if you have an efficient EV you should get 4kw per mile and theres two prices for 1kw: home charging is about 8p and rapid/high st whatever is about 70p today. So, assuming a tank of fuel is £1.50 a litre and you have a 45 litre tank, £67.5. Now in miles per gallon the Uk average is about 40, and theres 4.5 litres in a gallon. Luckily that means 10 gallons in a tank, so you should get 400 miles but mostly people get 350 miles from the £67.50.

Now, going back to the comparison, £10 at a public rapid in my efficient car is getting me, in winter, about 120 miles. So the equivalent mileage is roughly £30. In summer its about 20% more miles/less cost as the battery dosnt need heating to reach optimal output and roads are dry, no rain or snow etc. If I charge at home its about £3, using the cheapest tariff overnight etc the total cost for 360 miles is about £10.

The big problem people cant generally get their heads around is change in efficiency in seasonal weather. This does happen with petrol, engines run richer and hotter in winter to get the same output and a big loss in un-noticed efficiency because you can top up in under 5 minutes at any petrol station.

The other thing is maintenance cost and cost to run. EV motors have 2 moving parts and a solenoid, ICE have hundreds. Because EVs use engine braking properly theres no manual brake pad wear and tear but because EVs have zero or instant torque there is much higher tyre wear as the engine braking will use the rubber to slow the car as well as grip the road off the lights. The other big difference in cost is super efficient air conditioning which dosnt use petrol. You still need to re-gas but its a different ball game.

Theres no ulez, no c-charge and no road tax on EVs, at least until 2025 but probably longer as they need to work out a road tax system not based on emissions which is still being discussed rather than implemented. So you will save thousands a year in London, and hundreds in the UK generally, just on taxes and charges.