Dearborn, MI-Compressed natural gas is great, except for the filling station part.

It costs about $600,000 to install a pump for CNG, according to Sue Cischke, group vice president of sustainability, environment and safety engineering at Ford Motor Company.

"You aren't going to see them widespread," she added. "It  makes more sense for stationary power."

CNG is increasingly touted as the fuel of the future for the U.S., in part because of declining prices and large reserves. CNG also burns cleaner than traditional petroleum. While T. Boone Pickens and others have argued that it could become a stable of transportation, automakers to date have largely confined their CNG car offerings to taxi companies and other fleet car owners. Demand from trucking companies might increase--garbage giant Waste Management runs its trucks at the Livermore landfill in Northern California on CNG harvested from waste--but trucks can be scheduled to ply regular routes. CNG stations could potentially be erected on major highways. The driving habits of average consumers are more random.

Dual fuel cars that can run on CNG or regular gas likely won't be a popular item either because many of the benefits get lost. And, again, dual fuel cars would invariably run on petroleum

"It will always be somewhat gated by the infrastructure that is there," she added. (I'll have more from Ford, but I forgot a USB cable so can't download video just yet. There's your transparency in the media moment.)

The high cost of filling stations has also kept a lid on ethanol, according to executives at other companies. A new ethanol pump can run $100,000 to $150,000. Most flex fuel cars in the U.S., automakers admit, run on gas. Propane suffers from a similar lack of infrastructure: about 5 million forklifts run on it but passenger cars are rarer.