A Natural Gas Vehicle (NGV) utilizes compressed natural gas (CNG) or liquefied natural gas (LNG) as an alternative fuel source. Distinguished from autogas vehicles fueled by liquefied petroleum gas (LPG), NGV's rely on methane combustion, resulting in cleaner emissions due to the removal of contaminants from the natural gas source.

Natural gas vehicles are primarily medium- and heavy-duty vehicles. They are manufactured to either run on natural gas only or as “bi-fuel” vehicles that are able to run on gasoline or diesel when natural gas is not available. Bi-fuel vehicles require a second fuel tank, which increases the vehicle's weight and decreases its storage space.

Natural gas cars, known as compressed natural gas (CNG) cars, are powered by natural gas instead of gasoline or diesel fuel. Natural gas burns cleaner than gasoline, but vehicles using it have a shorter driving range compared to gasoline-powered cars.