CNG vs Petrol vs Electric: Running Cost Per Km in India (2026)

What does each kilometre actually cost you? At mid-2026 prices, an EV on home charging runs at roughly Rs 1–1.5/km, CNG at Rs 2.5–3/km, diesel at Rs 5–6/km and petrol at Rs 6–8/km. This guide breaks down the per-km maths, CNG conversion economics and the 5-year total cost of ownership.

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The Per-Km Numbers, Side by Side

Fuel typeRunning costBasis
Electric (home charging)Rs 1–1.5/kmResidential tariff ~Rs 7/unit, ~15 kWh/100 km
Electric (public fast charger)Rs 2.5–3.5/kmRs 15–22/unit operator rates
CNGRs 2.3–3/kmRs 75–90/kg, 30–33 km/kg factory-fitted
DieselRs 4.5–5.5/kmRs 89–95/L, 18–22 km/L
PetrolRs 6–7.5/km cityRs 96–105/L in metros, 14–16 km/L

These figures use real-world efficiency, not ARAI lab numbers; results vary with driving style, traffic and AC use. Track your city's daily rates on the Fuel Price page.

CNG: The Practical Choice for High-Mileage Drivers

CNG is available in 300+ Indian cities, strongest in metros and tier-2 cities across UP, Haryana, Gujarat, Rajasthan and Maharashtra. Factory-fitted CNG (Maruti S-CNG, Hyundai Hy-CNG, Tata CNG) is the recommended route; aftermarket sequential kits cost Rs 15,000–25,000 installed and should be PESO-approved. For a driver doing about 1,500 km/month, a Rs 20,000 kit pays back in roughly 14 months, with annual savings of Rs 50,000–65,000 versus petrol. The trade-offs: the cylinder eats 30–40% of boot space and filling queues can run 15–30 minutes at peak hours.

Important compliance point: an aftermarket CNG kit must be endorsed on your vehicle's RC at the RTO within 30 days of installation (Form 20 with the kit certificate, insurance endorsement and pollution check). Driving without the RC amendment is a traffic offence and can void your insurance in a CNG-related claim. Verify your registered fuel type anytime with RC Search.

EV: True Cost Including Charging

Home charging at Rs 7/unit works out to about Rs 1.05/km; public DC fast chargers from operators like Tata Power EV, Ather Grid, ChargeZone and Statiq cost Rs 15–22/unit, or roughly Rs 2.7/km. EVs also skip oil changes and timing belts, saving around Rs 8,000/year in maintenance, and most OEM battery warranties run 8 years or 1.6 lakh km.

The 5-Year Ownership Picture

Over 72,000 km (1,200 km/month), a petrol hatchback spends roughly Rs 4.3 lakh on fuel, a factory CNG car about Rs 1.8 lakh, and a small EV about Rs 1.1 lakh on home charging. For city drivers above 1,000 km/month, EV or CNG typically saves Rs 50,000–1,00,000 per year versus petrol; under 500 km/month, petrol usually remains the sensible choice. Pair whichever fuel you choose with the habits in our fuel saving tips to trim costs further.

Frequently asked questions

Is CNG cheaper than petrol everywhere in India?

In every city where CNG is available, the per-km cost is typically 2 to 3 times lower than petrol. But availability is limited to around 300+ cities, and networks are thin in hilly states like Himachal and Uttarakhand and much of the northeast.

How much does a CNG conversion kit cost, and is it worth it?

A PESO-approved sequential kit costs Rs 15,000-25,000 installed. A driver doing about 1,200 km/month saves roughly Rs 3,500-4,500 monthly versus petrol, so the kit pays for itself in months, with multi-year savings exceeding Rs 1 lakh.

What does an EV cost per km at home versus a public charger?

At a Rs 7/kWh home tariff and 15 kWh/100 km consumption, about Rs 1.05/km. At a public DC fast charger charging Rs 18/kWh, around Rs 2.7/km. Since most owners charge mainly at home, blended real-world cost is typically Rs 1.2-1.8/km.

Do I need to update my RC after installing a CNG kit?

Yes, it is mandatory. Get the fuel type endorsed on your RC at the local RTO within 30 days using Form 20, the PESO kit certificate, insurance endorsement and a pollution check. Skipping this is a traffic offence and can void insurance in a CNG-related claim.

Does an EV really save money given the higher purchase price?

For city drivers doing 1,000+ km/month, yes - break-even versus an equivalent petrol car is typically 2.5 to 4 years, after which every km is far cheaper. Under about 600 km/month, the savings usually do not justify the premium.