The group says there were 130,000 CNG vehicles across the country in 2005, and one in five new transit busses are CNG powered. Estimates place the worldwide use at 5 million vehicles.
More technology is needed to convert passenger cars and light trucks. Honda does offer the Civic GX NGV. Because the fuel is a gas, there are no lubricating qualities and hardened valves must be installed. A higher compression ratio can be used with CNG's 130 octane rating.
About 1,300 CNG refueling stations can be found in the United States, and some companies are offering compressors that hook up to a home's natural gas line. The biggest problem is fuel storage. The CNG equivalent of four gallons of gasoline would fill an average trunk, therefore limiting its range to around 120 miles if it got 30 miles to the gallon. The Honda GX NGV carries the equivalent of eight gallons for a range of 250 miles.