EV vs Petrol: The Real UK Cost Comparison, Year by Year

The purchase-price gap is real, but narrowing

New petrol cars in the UK average roughly £25,000-£35,000, while new electric hatchbacks such as a Nissan Leaf or MG4 EV typically start around £30,000-£38,000 — larger models and premium brands push well past £50,000. The gap is real, but the used-EV market is maturing fast: older Nissan LEAFs can now be found under £12,000, and the spread between new and used EV prices is shrinking every year as more early EVs reach the secondhand market.

Where EVs actually save money: running costs

At roughly 40mpg and £1.50/litre, a petrol car covering 100 miles costs about £7.50 in fuel. A modern EV, at 3-5 miles per kWh and roughly 32p/kWh on public rates, covers the same distance for about £6-£9 — but charging overnight at home, often nearer 8p-30p/kWh depending on tariff, can cut that to as little as £4-£6 per 100 miles. Fuel and electricity cost is where the biggest long-term savings for EVs consistently show up.

petrol:  cost per 100mi = (100/mpg) * 4.546 litres/gal * price_per_litre
EV:      cost per 100mi = (100/mi_per_kWh) * price_per_kWh

Maintenance tells the same story: routine EV servicing runs around £300-£600 over five years, versus roughly £800-£1,500 per year for a petrol car once oil changes, brake wear and exhaust repairs are included. EVs also benefit from regenerative braking, which extends brake-pad life substantially, and pay zero UK road tax versus £190-£370+ a year for petrol cars depending on CO2 rating.

The cumulative-cost crossover

Because the EV starts more expensive but runs cheaper every year, total cost of ownership for the two vehicles traces two lines that start apart and converge over time. The break-even year is where the EV's cumulative cost (purchase price plus every year's running costs) first drops to or below the petrol car's. Higher annual mileage and a bigger fuel-versus-electricity price gap both pull that year earlier; a small purchase premium does the same.

cumulative_cost(year) = purchase_price + Σ(annual running cost) up to that year

break-even year = first year where EV cumulative cost ≤ petrol cumulative cost

What the model leaves out

Three factors matter but are hard to model precisely. Battery degradation: all EV batteries lose some range over time, and full replacement (rarely needed within typical ownership) currently costs roughly £7,000-£12,000, though battery technology and warranties are improving quickly. Insurance: EV premiums currently run about 10-20% higher than petrol equivalents, reflecting higher vehicle values and repair costs. Government incentives: schemes like the Plug-in Vehicle Grant have shifted the upfront price gap over time and may not apply by the time you're comparing cars.

Frequently asked questions

Try it live

Everything above runs in your browser — open EV vs Petrol Cost and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.