One of the biggest reasons people switch to electric is lower running cost. The saving depends on where you charge, your electricity price and your vehicle's efficiency, so the best way to compare is with your own numbers.
The method
- Petrol cost per km = petrol price per litre ÷ kilometres per litre.
- EV cost per km = charging price per kWh ÷ kilometres per kWh.
An illustrative example
The figures below are assumptions for illustration only. Prices and efficiency vary by city, tariff, vehicle and driving style.
| Vehicle and fuel | Assumptions | Energy cost per km |
|---|---|---|
| Petrol car | ₹100 per litre, 15 km per litre | About ₹6.7 |
| EV, public DC fast charging | ₹22 per kWh, 7 km per kWh | About ₹3.1 |
| EV, home charging | ₹8 per kWh, 7 km per kWh | About ₹1.1 |
In this example, home charging costs about a sixth as much per kilometre as petrol, and even public fast charging costs less than half. Your own figures will differ, so plug in your numbers.
What affects your result
- Where you charge: home and workplace AC charging is usually much cheaper than public fast charging.
- When you charge: time-of-day tariffs can make off-peak or solar-hour charging cheaper.
- Efficiency: highway speeds, air-conditioning and load reduce kilometres per kWh.
- Two- and three-wheelers: their efficiency is much higher per kWh, so the per-km cost is even lower.
Beyond energy
EVs also tend to need less routine maintenance, with no engine oil, fewer moving parts and less brake wear thanks to regenerative braking. For a full comparison, add maintenance, insurance and purchase price over the years you will own the car.