CNG stands for Compressed Natural Gas. It is a gaseous fuel and is a mixture of hydrocarbons – mainly Methane. For use in Automobiles as fuel, it is compressed to a pressure of 200-250 Kg/cm2 to enhance the vehicle’s onboard storage capacity.

Yes, it is safe. The properties of CNG make it a safe fuel. It is lighter than air, so in case of a leak it just rises up and disperses into the atmosphere. Besides, a high auto-ignition temperature of 540°C as against petrol’s 360°C makes it a safe fuel. Also, in case of a leak, if CNG’s concentration in the air is less than 5% and more than 15%, the gas will not burn even in the presence of a spark.

All spark-ignited engines can be converted to CNG, but a specially designed conversion kit is required for the purpose. The kit consists of a cylinder to be fixed in the boot of the car and other equipment to allow gas flow into the engine. Of late, research is on for converting diesel-run vehicles to dual-fuel with CNG.

Yes, after conversion to CNG the vehicle can run on petrol whenever desired simply by flicking a switch on the dashboard. These are called dual-fuel vehicles.

The cost of converting a vehicle to CNG depends on its type and make, and may range anywhere from ` 26,000.00 to around ` 50,000.00

CNG cylinders are manufactured from a special steel alloy and are seamless in construction. Their compact size allows them to easily fit even in a small car. An empty CNG cylinder with a 50 water liter carrying capacity (WLC) weighs 48 kg, with a length of 835 mm and a diameter of 316 mm, and can store approximately 8 to 9 Kgs of CNG – depending upon filling conditions, gas density, etc. The 50 WLC capacity cylinder is the one most regularly used – with cylinders of 45 WLC, 55 WLC, 60 WLC and 65 WLC capacity are used as well.

The mileage depends upon city road conditions and may vary from vehicle to vehicle and driving habits. A cylinder with a 50-liter water-carrying capacity is capable of carrying approximately 9 kg of CNG. This is equivalent to 12.5 liters of petrol and will allow a run of about 150-160 km for a medium sized 1300 CC car. Also, many OEM manufactured and retrofitted cars have electronic fuel gauge indicators fitted on the dashboard that give an approximate idea about CNG remaining in cylinders.

CNG cylinders are designed and built in such a way so as to withstand high pressure. The maximum pressure in a CNG cylinder is up to 200 kg/cm2 (g) (about 2840 psi[g]). CNG cylinders are safe as they are manufactured as per specific requirements and tested before use, in accordance with international specifications and standards and they are duly approved by Chief Controller of Explosives. Moreover, these have been provided with a ‘safety burst disc’ such that in case of inadvertent high-pressure/high temperature at the time of filling or at any other time, this disc is ruptured and pressure released. Further, these cylinders are to be re-tested every three years at CNG Cylinder Retesting Cylinders approved by Petroleum and Explosives Safety Organisation (PESO). Please refer here for a list of PESO approved CNG Cylinder Hydro-testing Centers, or alternatively on

The fuel bill on the basis of the average running of the vehicle is reduced by approximately 50 percent after conversion of CNG at the present price of CNG & Petrol in Pune. For detailed savings, please refer Savings Calculator.

CNG kit is safe and simple. It gives years of trouble-free operation. It doesn’t require frequent servicing. Just as for all other fuels, it is advised to have routine services. An authorized person should be consulted for service. As per Gas Cylinder Rules, 1981, the cylinder should undergo hydro-stretch testing every 3 years to check pressure tolerance.

Yes. All major commercial vehicle manufacturers like TATA, Mahindra, Eicher, SML etc. have CNG variants of their popular models. Also, many passenger car manufacturers like Maruti, TATA, etc. have factory-fitted car models available. Other popular car manufacturers like Hyundai, GM, etc. provide pre-delivery CNG kit retro-fitment of their authorized CNG kits at dealer end.

Owing to CNG’s distinct features, it does not contaminate or dilute crankcase oil, giving a new lease of life to the engine. The absence of any lead content in CNG helps avoid lead fouling of plugs, thereby enhancing plug life. One of the important benefits of CNG is that upon entering the engine in the form of a gas (and not as a spray or mist like other fuels), it doesn’t disturb the presence of lubricating oil in the engine and reduces chances of wear and tear.

Yes, a diesel vehicle can be converted to run on CNG, but the conversion cost is higher than the conversion of petrol vehicles and under the current technology it cannot run on dual fuel mode. However, research in India is in process for allowing diesel-run vehicles to function as dual-fuel on CNG.

CNG is an environment-friendly fuel. The natural gas is mainly composed of methane and its exhaust emissions consist of water vapours and a small fraction of carbon monoxide. The absence of carbon and other particulates result in negligible amount of harmful elements in exhaust fumes.

CNG emits less carbon dioxide and other pollutants as compared to liquid fuels. Thus, CNG contributes in lowering air pollution, also helps in improving the Balance of Payments by acting as a substitute for imported liquid fuels, provides more business and job opportunities with the opening up of a new sector, and being competitively priced, it appeases motorists.

Natural gas as a vehicle fuel has a long and established record in Europe, Canada, India, New Zealand, Australia and in USA. Other countries such as Japan, Mexico, Malaysia, Pakistan, and Bangladesh are recognizing the benefits of CNG and plan to expand its use.

An LPG-fuelled vehicle will not run on CNG as the two fuels are different from each other, have differing calorific values and need different air-fuel ratios for combustion. CNG has to be stored at relatively higher pressure in a cylinder than LPG, so the same cylinder cannot be used for both gases. A vehicle will need specific conversion for CNG operation. For list of RTO authorized CNG retrofitters, please refer here or Regional Transport Office, Pune/Pimpri-Chinchwad.

Other than Pune and Pimpri-Chinchwad in Maharashtra, CNG is readily available in Mumbai, Thane, Navi-Mumbai, Mira-Bhayander, etc. Other nearby cities are Indore, Surat, Vadodara, Ahmedabad and almost all of Gujarat. CNG is also present in Delhi and around 25 other cities of the country.

The CNG cylinder is fixed in the luggage space of your car. It is fastened with a metal strap so that it does not move while the car is running. As per BIS code, it has to be a permanently fitted tank and should be integral part of vehicle (as per BIS 14899 for fuel tank container and as per LPG/CNG Control order).