Benefits of CNG Environmentally Friendly, Reduced maintenance cost, CNG Produces significantly less Pollutants than petrol/diesel, natural gas is cheaper & safer than Petrol/diesel, Green fuel. Greenfuel: Commonly referred to as the green fuel because of its lead and sulphur free character, CNG reduces harmful emissions thus reducing the effect of global warming. Being non-corrosive, it enhances the longevity of spark plugs. Due to the absence of any lead or benzene content in CNG, the lead fouling of spark plugs, and lead or benzene pollution are eliminated. Safety: CNG is less likely to auto-ignite on hot surfaces, since it has a high auto-ignition temperature (540 degrees centigrade) and a narrow range (5%-15%) of in flammability. It means that if CNG concentration in the air is below 5% or above 15%, it will not burn. This high ignition temperature and limited flammability range makes accidental ignition or combustion very unlikely. Low operational cost: The operational cost of vehicles running on CNG, as compared to those running on other fuels, is significantly low. At the prevailing price of fuel in Delhi, Operational cost of CNG vehicles is 66% lower than petrol and 28% lower than diesel. Increased life of oils: Another practical advantage observed is the increased life of lubricating oils, as CNG does not contaminate and dilute the crankcase oil. Mixes evenly in air: Being a gaseous fuel CNG mixes in the air easily and evenly.