CNG vehicles are natural gas vehicles that are powered by compressed natural gas, or CNG. CNG is a colorless, odorless and non-corrosive alternative fuel that is made by compressing natural gas to pressures of at least 3,100 pounds per square inch.
The high-pressure natural gas is stored in thick-walled tanks aboard the vehicle. The CNG fuel system carries pressurized natural gas from the storage tanks, reduces its pressure and injects it into the engine intake air. The engine then compresses the gas-air mixture and ignites it using a spark plug. Dedicated CNG vehicles, such as the Honda Civic Natural Gas Sedan, run purely on CNG, whereas bi-fuel CNG vehicles, such as the 2015 Chevrolet Silverado, run on either gasoline or CNG.