Natural Gas Vehicles
As of 2009, the U.S. had a fleet of 114,270 compressed natural gas (CNG) vehicles, mostly buses; 147,030 vehicles running on liquefied petroleum gas (LPG); and 3,176 vehicles liquefied natural gas (LNG). Other countries where natural gas-powered buses are popular include India, Australia, Argentina, and Germany. In OECD countries there are around 500,000 CNG vehicles. Pakistan's market share of NGVs was 61.1% in 2010, follow by Armenia with 32%, and Bolivia with 20%. The number of NGV refueling stations has also increased, to 18,202 worldwide as of 2010, up 10.2% from the previous year.
Existing gasoline-powered vehicles may be converted to allow the use of CNG or LPG. An increasing number of vehicles worldwide are being manufactured to run on CNG. The Honda Civic GX is the only NGV commercially available in the US market., although Ford offers a prep package on certain models. GM do Brasil introduced the MultiPower engine in August 2004 which was capable of using CNG, alcohol and gasoline (E20-E25 blend) as fuel, and it was used in the Chevrolet Astra 2.0 model 2005, aimed at the taxi market. In 2006 the Brazilian subsidiary of FIAT introduced the Fiat Siena Tetra fuel, a four-fuel car developed under Magneti Marelli of Fiat Brazil. This automobile can run on natural gas (CNG); 100% ethanol (E100); E20 to E25 gasoline blend, Brazil's mandatory gasoline; and pure gasoline, though no longer available in Brazil it is used in neighboring countries.
Despite its advantages, the use of natural gas vehicles faces several limitations, including fuel storage and infrastructure available for delivery and distribution at fueling stations. Natural gas must be stored in cylinders, whether it is CNG (compressed) or LNG (liquefied), and these cylinders are usually located in the vehicle's trunk, reducing the space available for other uses, particularly during long distance travel. This problem can be solved in factory-built CNVs that install the tanks under the body of the vehicle, thanks to a more rational disposition of components, leaving the trunk free. As with other alternative fuels, natural gas distribution to and at fueling stations, as well as the number of stations selling CNG are other barriers for widespread use of NGVs. CNG-powered vehicles are considered to be safer than gasoline-powered vehicles. CNG may also be mixed with biogas, produced from landfills or wastewater, which doesn't increase the concentration of carbon in the atmosphere.
NGV's can be refueled anywhere from existing natural gas lines. This makes home refuelling stations that tap into such lines possible. A company called FuelMaker pioneered such a system called Phill Home Refueling Appliance (known as "Phill"), which they developed in partnership with Honda for the American GX model. Phill is now manufactured and sold by BRC FuelMaker, a division of Fuel Systems Solutions, Inc.