As a substitute fuel, natural gas has many constructive attributes. Natural gas vehicle functions using compressed gas stored in a fuel tank. The tube like shaped tank is normally attached to the back, top or undercarriage of a vehicle and is filled again in a manner similar to a normal gasoline tank.
To run competently, a natural gas powered engine needs many modifications from its gasoline counterpart. Some natural gas vehicles are bio-fuel vehicle which means that they can run on either gasoline or natural gas thus increasing the available range of travel.
A main restraint to using natural gas powered vehicles is their restricted range between fill-ups and also a readily available refueling infrastructure is at present not in place.
Honda has produced one of the best natural gas vehicles presently available in the market. The 2008 Honda Civic GX NGV is an outstanding example of what the future may hold for natural gas vehicles.