Conversion or new purchase?
Converting a vehicle to run on natural gas is usually expensive and uneconomical. Therefore, CNG cars are usually offered as new cars. Examples of natural gas-powered passenger cars include the VW Caddy and Seat Leon; in the commercial sector, VW, Fiat/Iveco, Volvo and Scania all have CNG offerings. The inspection of a vehicle equipped with natural gas drive is not much more expensive than a petrol vehicle. One cost consideration, however, is routine gas system inspections.
H-Gas or L-Gas?
CNG is offered in Germany as H-gas and L-gas, with L-gas being more widely available in northern and eastern Germany. H-gas has higher methane content, so it is more efficient and also more expensive in terms of price per kg. As you would expect, vehicles with H-gas consume less and have a longer range.