Petrol vs diesel vs CNG vs EV

Compare what each fuel really costs to run. Enter your monthly distance and the prices you pay to see the cost per kilometre and per month — the cheapest is highlighted.

Cheapest

Petrol

per km
per month
Cheapest

Diesel

per km
per month
Cheapest

CNG

per km
per month
Cheapest

EV

per km
per month

How the comparison works

Cost per km = Price of energy ÷ Distance per unit

For each option the price of one unit of energy is divided by how far the vehicle travels on that unit — litres for petrol and diesel, a kilogram for CNG, and a kWh for an EV. Multiplying by your monthly distance gives the monthly running cost. The figures cover energy only, not the price of the vehicle or servicing.

FAQs about fuel comparison

How do I compare petrol, diesel, CNG, and EV running costs?

Work out the cost per kilometre for each — fuel price divided by efficiency — then multiply by the distance you drive. This tool does it for all four at once and highlights the cheapest.

Why is CNG often the cheapest to run?

CNG usually costs less per kg than petrol per litre, and CNG vehicles travel a good distance per kg, so the cost per kilometre tends to be the lowest of the fuels.

Are EVs really cheaper per kilometre?

On running cost alone, electric vehicles are usually the cheapest because electricity per kWh is inexpensive and motors are efficient. This tool compares running cost only, not the purchase price.

What efficiency figures should I use?

Use your own vehicle’s numbers if you have them. Typical values are petrol 16 km/L, diesel 20 km/L, CNG 26 km/kg, and EV 7 km/kWh.

Does this include servicing or purchase price?

No. It compares only the energy cost of driving. Diesel and EV vehicles often cost more to buy, while servicing varies by vehicle, so factor those in separately.

Which prices should I enter?

Use the latest pump price in your area for petrol, diesel, and CNG, and your home or public charger tariff per kWh for the EV.

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