GM to sell Bi-Fuel Chevrolet Silverado and GMC Sierra 2500 HDs image

General Motors Sunday announced that will sell pickups that run on both gasoline and compressed natural gas, potentially reducing costs for users.

The trucks will be built by GM in Fort Wayne, Ind., and sent to a supplier that will retrofit them to use compressed natural-gas tanks.

The vehicles – the 2013 Chevrolet Silverado and GMC Sierra 2500 HD – include a compressed natural gas (CNG) capable Vortec 6.0L V8 engine that seamlessly transitions between CNG and gasoline fuel systems. According to the automaker, the trucks offer a range of more than 650 miles.

A vehicle such as the ones GM will offer can save a driver $6,000 to $10,000 in fuel costs over a three-year period because CNG is cheaper than gasoline, Joyce Mattman, director of GM commercial product and specialty vehicles, said before the announcement.

GM didn’t disclose the prices of the vehicles, and any premium over gasoline-only cars might offset savings on fuel.

CNG offers benefits in increased fuel efficiency and reduced emissions. It generates 25 percent less carbon dioxide and is in abundant supply. The infrastructure is growing, too. Since 2009, the number of CNG stations has increased 26 percent.

Natural gas costs on average one-third less than conventional gasoline and there are 1,000 CNG-fueling stations in the U.S., of which about half are open to the public, according to Natural Gas Vehicles for America, a trade group based in Washington.