CNG vs petrol: how fast does a CNG car pay for itself?
CNG vs petrol cost comparison for Indian car owners: per-km cost, annual savings, break-even kilometres, and the trade-offs nobody mentions (boot space, power, queues).
Updated 2026-08-04 · figures computed from the same engine as our fuel cost calculator
CNG costs ₹3 less per kilometre to run than petrol — about ₹38,800 a year at 1,000 km a month. But it costs roughly ₹90,000 more to buy, so you need about 27,835 km — roughly 2.3 years of average driving — before you are actually ahead.
Petrol
Lowest upfront cost, widest service network, best resale liquidity in the used market.
CNG
Cheapest running cost of any ICE option, but boot space is lost to the cylinder, power drops ~10%, and refuelling queues are long outside metros.
Running cost by how much you drive
| Monthly driving | Petrol | CNG | You save |
|---|---|---|---|
| 500 km Light city use |
₹3,200/mo ₹38,400/yr |
₹1,583/mo ₹19,000/yr |
₹19,400/yr |
| 1,000 km Average commute |
₹6,400/mo ₹76,800/yr |
₹3,167/mo ₹38,000/yr |
₹38,800/yr |
| 1,500 km Heavy commute |
₹9,600/mo ₹1,15,200/yr |
₹4,750/mo ₹57,000/yr |
₹58,200/yr |
| 2,500 km Very high / commercial |
₹16,000/mo ₹1,92,000/yr |
₹7,917/mo ₹95,000/yr |
₹97,000/yr |
Fuel/energy cost only. Servicing, insurance and depreciation differ too — use the true cost of ownership calculator for the full picture.
How long until cng pays back
| If you drive | Break-even takes |
|---|---|
| 500 km/month | 4.6 years |
| 1,000 km/month | 2.3 years |
| 1,500 km/month | 1.5 years |
| 2,500 km/month | 11 months |
Break-even = the ₹90,000 purchase premium divided by the ₹3/km running-cost saving. If you plan to keep the car less time than this, the cheaper-to-buy option wins.
Common questions
Is a CNG car worth it over petrol in India?
CNG costs ₹3,233 less per 1,000 km to run, but costs about ₹90,000 more to buy. You need roughly 27,835 km to break even — around 2.3 years at 1,000 km a month. Drive more than that and cng wins; drive less and petrol is the cheaper overall choice.
What is the running cost per kilometre of petrol vs cng in India?
At ₹96/L and 15 km/L, petrol costs about ₹6 per km. CNG at ₹76/kg and 24 km/kg costs about ₹3 per km. That is a difference of ₹3 per kilometre, or ₹38,800 a year at 1,000 km a month.
How much can I save a year with cng over petrol?
At 1,000 km a month you save about ₹38,800 a year. At 1,500 km a month it is roughly ₹58,200, and at 2,500 km a month about ₹97,000. These are fuel/energy costs only — servicing and insurance differences are on top.
What are the downsides of cng?
Cheapest running cost of any ICE option, but boot space is lost to the cylinder, power drops ~10%, and refuelling queues are long outside metros.
Other comparisons
Prices are indicative all-India averages and move daily — Delhi, Mumbai and Bengaluru typically differ ₹2–5 per litre from the national average. Mileage figures are realistic city-driving estimates, not ARAI claims.