The full form of CNG is Compressed Natural Gas. CNG is a fuel source that compresses natural gas, primarily methane, to less than 1% of the volume it occupies at standard atmospheric pressure. It is stored and distributed in hard cylindrical and spherical tanks. CNG is mostly methane, which releases energy when combusted with air. Although CNG can be used in its gaseous or liquid form, most vehicles use the gaseous form compressed to 3000 PSI. CNG is considered an eco-friendly fuel source and is becoming increasingly popular as a fuel for vehicles, particularly in countries where natural gas is abundant. Some advantages of CNG include:

• It is cheaper than diesel and petrol used to run buses and other automobiles.
• The cost of maintenance of cars running on CNG is low.
• It releases fewer toxic and unnecessary gases than other alternatives, such as petrol and diesel.
• It extends the life of spark plugs.

CNG is mostly composed of methane, which is a highly flammable and colorless gas. It also contains small amounts of other gases, including ethane, propane, butane, and carbon dioxide. CNG is an odorless, colorless, and tasteless compound with noncorrosive and nontoxic properties.