EV running costs vs petrol

The petrol cost per km depends on two things: the pump price and the car's real-world fuel consumption. The formula is simple:

You can look up the current national average petrol price for your country in the FuelTheGuide Explorer. For fuel consumption, use the real-world figure for your car — official WLTP ratings typically understate real consumption by 15–25%. A mid-size petrol sedan averages 6.5–8.5 L/100 km in mixed driving; SUVs and larger cars sit at 9–13 L/100 km.

For diesel, substitute the diesel pump price and a slightly lower consumption figure (diesel cars typically use 15–20% less fuel by volume than their petrol equivalents). Our guide on petrol vs diesel running costs goes deeper on this comparison.

The equivalent formula for an electric vehicle uses the electricity tariff and the EV's consumption in kWh per 100 km:

A typical compact EV uses 14–18 kWh/100 km in real-world mixed driving; larger SUV-style EVs use 20–28 kWh/100 km. As with petrol consumption, real-world figures diverge significantly from manufacturer claims, especially in cold weather (more on this in Step 5).

The critical variable is which electricity price you use — covered in the next step.

Most EV drivers use a mix of home charging (slow, cheap, overnight) and public charging (faster, significantly more expensive). The split between the two can determine whether an EV is cheaper or more expensive than petrol per km.

Blend these costs by your estimated charging split. A driver who charges 80% at home and 20% at public chargers has a very different effective cost per km than one who charges 50% at motorway rapid chargers (e.g., long-distance commuters or those without home charging).

Electricity is taxed differently from vehicle fuel in every country — and the difference is not always in the EV's favour. Some key patterns:

• France levies relatively low electricity taxes (TURPE network tariff + TICFE excise), keeping residential tariffs below EUR 0.25/kWh despite nuclear plant costs.
• Germany applies one of the world's highest electricity levies — the full suite of EEG renewable surcharge (now reduced), network charges, and VAT — pushing residential tariffs above EUR 0.30/kWh even after 2023 reforms.
• Norway subsidises residential electricity in winter months during price spikes, but base electricity prices can still be high relative to petrol in high-price periods.
• India keeps residential electricity tariffs low through cross-subsidies from industrial consumers, creating a large EV cost advantage over petrol in urban areas with reliable grid access.

For a country-level read on how pump prices compare, use the Explorer and set the unit to per-litre equivalent. Cross-referencing national electricity tariff data (available from national energy regulators or the IEA Energy Prices database) gives the full picture.

Both fuel consumption and electricity consumption vary with driving conditions. For a fair comparison, use figures that match your actual usage pattern.

The table below uses illustrative mid-2024 prices and typical real-world efficiency figures (7.5 L/100 km for petrol sedan; 18 kWh/100 km for compact EV). Home charging tariff assumed.

Illustrative figures only. Local prices change weekly. Use the Explorer for the latest petrol prices; source electricity tariffs from your national regulator.

A comprehensive petrol vs electric car cost calculator needs to go beyond fuel cost per kilometre to include purchase price, depreciation, insurance, maintenance, and road tax differences. On pure running costs (fuel/electricity), EVs are typically 30-60% cheaper per kilometre than petrol cars when primarily home-charged. However, the total cost of ownership equation depends heavily on annual mileage — high-mileage drivers (20,000+ km/year) reach EV cost parity faster because the fuel savings accumulate against the higher purchase price. The IEA Global EV Outlook provides detailed total cost of ownership comparisons by country and vehicle segment. For UK-specific calculations, the UK government's EV Energy Taskforce report analyses charging infrastructure costs and their impact on running costs.

Hybrid vs petrol fuel costs represent a middle ground. Conventional (non-plug-in) hybrids use a small battery and regenerative braking to improve fuel economy by 20-35% in urban driving compared to an equivalent pure petrol car, but offer minimal improvement on motorway journeys. Plug-in hybrids (PHEVs) can run 40-80 km on electricity alone before switching to petrol, making them very cheap to run for short daily commutes if charged regularly, but no better than a petrol car on long journeys. The real-world challenge with PHEVs is that many owners do not charge them regularly — studies by the IEA on PHEV real-world emissions show that actual fuel consumption can be 2-4x the official WLTP figure when the battery is rarely charged. For drivers considering a switch, the most accurate cost comparison uses your actual annual mileage, your home electricity tariff, and current pump prices from the explorer.

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