What a Factory CNG Kit Actually Costs

A factory CNG car is the same car with a steel cylinder in the boot, a second fuel system and a manufacturer's warranty over both. What it is not is a fixed surcharge. Across 99 matched pairs — same trim, same gearbox, same engine, the only difference being the fuel system — the option runs from ₹63,000 to ₹1,30,000, with a median of ₹1,00,000.

Every figure here is a difference between two prices we hold for the same car, so it carries no estimate and no assumption about what a kit is worth. What it cannot tell you on its own is running cost: that needs a CNG price per kilogram, which varies by city. We hold one supplier price, for Delhi, and the payback section below uses it.

What it costs, car by car

Efficiency is the manufacturer's certified figure for that car's cheapest matched pair. CNG is measured in km/kg and petrol in kmpl — they are different units and the two columns are not directly comparable as they stand; turned into rupees per kilometre, below, they are.

Sold with factory CNG but not in this table, because no petrol variant shares the CNG version's trim, gearbox and engine: Maruti Ertiga. The Ertiga's CNG is sold only as VXi(O) and ZXi(O), against a plain petrol VXi and ZXi, so the gap between them would include whatever the (O) pack adds.

When does the CNG kit pay for itself?

Divide each fuel's price by the certified efficiency and both become rupees per kilometre. At Delhi prices — petrol ₹102.12 a litre and CNG ₹86.98 a kg — CNG saves ₹1.43 to ₹1.93 a kilometre on the 15 cars where the manufacturer certifies both engines, and repays the kit in 43,710 km to 65,525 km — 3.6 to 5.5 years at 12,000 km a year.

Months to pay back, by how far you drive

The years in the first table assume 12,000 km a year, which is 1,000 km a month. The cylinder also sits in the boot and takes space there, and a CNG car has to be refilled at a CNG station; neither is priced here.

Ex-showroom, Delhi; each car's cheapest matched trim. CNG ₹86.98/kg is Indraprastha Gas Limited (IGL)'s Delhi price from 29 August 2026; petrol is Delhi's pump price read 4 November 2026. Certified efficiency is measured on a fixed test cycle, not your commute, and a CNG car also burns some petrol to start. Outside Delhi the CNG price differs, so these figures are Delhi's. 11 cars are left out because one of the two engines has no certified figure.

The same kit, different prices on the same car

A CNG cylinder is the same hardware whichever trim it sits in, so the obvious expectation is one price per car. 5 of the 20 cars here with more than one matched pair do exactly that. The rest do not, and the Tata Nexon spreads furthest: ₹63,000 on one trim and ₹1,05,000 on another — ₹42,000 of difference for the same fuel system.

That is worth knowing before you settle on a trim. Where the premium varies, the cheapest way into CNG on a given car is not always the trim you first looked at — and on several cars the CNG option is not offered on the entry trim at all, which is its own, larger cost.

Why we do not score this

Our value engine prices equipment, and a fuel system is not equipment any more than a gearbox is. So a petrol-to-CNG upgrade returns not comparable rather than a verdict — the same refusal that keeps every automatic in India from being marked down for not being a feature. The price difference above is the honest answer instead: a number, with no judgement attached to it.