Clean, green and cost-efficient vehicles have arrived in Oklahoma.

Fueling these cars is something that’s been around for a long time — natural gas.

The Honda Civic GX, the only vehicle commercially available in the U.S. that runs on Compressed Natural Gas, is already on Oklahoma highways. State legislators want to encourage growth in the developing CNG car market.

House Speaker Chris Benge announced last week that Oklahoma Republican leadership “will be looking at options to incentivize growth in the compressed natural gas car market.”

Touted by the Environmental Protection Agency as the “cleanest internal combustion vehicle on Earth,” the technology has been around for over a decade.

Joe Marina Honda of Tulsa sold mover than 20 of the 2008 models, according to CNG Specialist and new car salesman Mark Sprowls.

Sprowls said the waiting list for 2009 models is long, but he expects to be able to fill all of the orders. Those cars should come in sometime after the first of the year.

“I have a 2008 myself,” Sprowls said.

Natural gas as a fuel is measured in a gasoline gallon equivalent for comparison to regular gasoline consumption in cars. Highway mileage on the Civic is 36 miles per gallon.

“I get 30 in town on mine,” Sprowls said.

Natural gas prices run one-fourth of gasoline prices, selling for an equivalent of 90-cents on the gallon, said Sprowls.

Locally, CNG can be obtained at the ONG Claremore Service Center, 1449 SW Country Club Road. The price is 90.9 cents per gallon. Fuel stations also available at locations in Tulsa, Broken Arrow, Sapulpa, Muskogee and other Oklahoma municipalities.

Based on an EPA worksheet available for the Honda Civic CNG, the cost to drive 25 miles at 80-cents per gallon using 0.89 gallon. The cost of a fill-up for a 13.2-gallon tannk would be $10.69. Those prices reflect an annual fuel cost of $482, with figures based on 45-percent highway, 55-percent city driving, 15,000 annual miles and a fuel price of 90 cents per gallon of CNG.

Sprowls said natural gas prices are regulated by the Oklahoma Corporation Commission and are due to increase Nov. 1. An exact figure is not available, but increasing demand will raise the cost. Even with an increase, the price is expected to stay far lower than gasoline costs.

CNG is a clean fuel and its use could help reduce U.S. reliance on imported oil, analysts say.