Governors from 13 states sent letters to 19 automakers this week, expressing their support for a higher penetration of compressed natural gas (CNG) vehicles in the U.S. This effort, led by Oklahoma Gov. Mary Fallin and Colorado Gov. John Hickenlooper, builds on a multi-state partnership that first took shape last fall.

The letters were directed to executives at a number of manufacturers with a presence in the U.S. - from GM, Ford and Chrysler to Mercedes-Benz, Porsche and Volvo, as well as major Asian automakers. The governors wrote that a partnership between states and auto manufacturers "makes sense" and could potentially usher in a wide variety of transportation fuels and alternative fuel vehicles.

However, the governors' emphasis is CNG, and they have gone so far as to promise a collective push to buy natural gas vehicles (NGVs) for their states' fleets.

"Natural gas presents a tremendous opportunity for America to realize an energy future using domestic resources to fuel our nation's transportation needs," the letter states. "To that end, we are committed to explore the aggregation of our annual state fleet vehicle procurements to provide an incentive to manufacture affordable, functional natural gas vehicles."

The letter also states that a joint request for information (RFI) will be forthcoming. That RFI will ask the automakers for their feedback on NGVs in anticipation of a multi-state solicitation, which Fallin's office says is planned for later this year.

Fallin has stated that she and her colleagues from around the country are trying to put NGVs into the mainstream. However, a lack of demand - coupled with a lack of CNG refueling infrastructure - has made automakers rightfully cautious about going gangbusters with CNG models.

The multi-state initiative is aimed at changing this landscape.

"CNG vehicles continue to be held back by a 'chicken and egg' scenario," Fallin said in a statement. "Consumers won't buy cars with limited fueling stations and high price points; and the industry can't build an affordable car without adequate demand. We can break that cycle by using the combined purchasing power of these 13 states."

In addition to Fallin and Hickenlooper, governors from Pennsylvania, Maine, West Virginia, Kentucky, Ohio, Mississippi, Louisiana, Texas, Utah, New Mexico and Wyoming are supporting the initiative.

"Recently, automakers announced several new original-equipment-manufactured natural gas vehicles. We believe this multi-state effort can create even more momentum," the governors' letter states.