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AutoClair index

Electric-car energy cost index — United Kingdom

Updated 4 August 2026 · 6 min read

This index applies the market's reference energy prices to three driving profiles. It isolates energy: vehicle price, finance, insurance, maintenance, tax and resale still need a separate comparison.

Central result

At 10,000 mi per year, the scenario estimates about £670 for electricity versus £1,690 for petrol, an annual energy-only difference of £1,020 in the EV's favour.

Three driving profiles

Results are rounded planning estimates. Replace prices and consumption with your observations before making a decision.

Annual mileageElectricPetrolAnnual difference
6,000 mi£400£1,010£610
10,000 mi£670£1,690£1,020
15,000 mi£1,000£2,500£1,530

Published assumptions

Published assumptionsPlanning value
Home electricity£0.26/kWh
Petrol£1.5/L
Electric consumption26 kWh/100mi
Petrol economy40 MPG

Calculation method

Electric = miles × electric consumption ÷ 100 × kWh price

Petrol = miles ÷ MPG × 4.54609 × price per litre

This is an energy index, not full TCO. Mostly public charging, cold weather, motorway use or different real consumption can materially change the result.
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Sources and method

Run the numbers for your own project

The AutoClair simulator compares the net cost of paying cash, an auto loan, a PCP, and a PCH over the same term, depreciation included.

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