Aftermarket CNG kits vs factory setups for Indian buyers

More car owners in India are looking at aftermarket CNG conversions to lower daily running costs as fuel prices climb. While factory-fitted options have grown, many popular models and automatic variants still leave buyers without a company-fitted gas option.

Types of CNG kits available

Older BS3 and earlier cars use Venturi kits costing Rs 30,000 to Rs 40,000, which are gradually being phased out. Naturally aspirated MPFI cars need sequential kits, priced from Rs 40,000 to Rs 50,000 for older BS4 models, Rs 50,000 to Rs 65,000 for smaller BS6 cars, and up to Rs 70,000 to Rs 75,000 for larger cars requiring eight injectors. Direct-injection turbo engines use DI kits costing Rs 1 lakh to Rs 1.5 lakh, running on an 80:20 CNG and petrol mix to keep injectors cool.

Installation and components inside the workshop

An installation takes four to five hours and involves a detailed process to ensure safety and proper calibration.

• Technicians inspect engine health and replace spark plugs if needed
• The 60 to 65 litre seamless steel tank is secured in the boot using reinforced brackets
• A MAP sensor and ECU are wired into the car to manage gas delivery
• Polymer-coated steel high-pressure lines route gas from the filling valve to the reducer
• Electronic gas detectors and soap solutions are used to check every connection for leaks before calibration and road tests

Warranties and legal requirements

Fitting an aftermarket kit voids the manufacturer warranty, though some installers provide third-party coverage through insurance partners. The installation must be approved, fitted by an authorized installer, and updated on the RC at the RTO, along with informing the insurance provider. Tanks also require mandatory hydrotesting every three years at around Rs 30,000, plus filter replacements every 10,000km.

Has anyone here done an aftermarket conversion on a car that lacks a factory CNG option, and how has your experience been with RTO paperwork and long-term reliability?