General Motors announced today it will offer bi-fuel versions of its 2013 Chevrolet Silverado and GMC Sierra pickup trucks that run either on gasoline or natural gas.

The two trucks are the 2500 HD (heavy duty) model, and can be ordered in rear-wheel or four-wheel drive and with a standard or long bed.

The pickups are fitted with a 6.0-liter V-8 engine that is modified to switch seamlessly between burning compressed natural gas, or CNG, and gasoline.

GM chose the bi-fuel option, it said, because it relieves buyers of the need to stay within range of a local natural-gas fueling stations.

No range anxiety

"Range anxiety is very real," said Joyce Mattman, director of GM commercial product and specialty vehicles. "We worked with the Chevy Volt team on that, and saw the same issues" among customers who worried about running out of electricity.

The trucks run on natural gas as standard, then switch to gasoline when the CNG runs out (or if the driver pushes a button to do so).

Natural gas-powered vehicles have lower emissions, producing about 25 percent less carbon dioxide (CO2) per mile than those running on gasoline.

The fuel is plentiful and domestically produced, with 98 percent of U.S. natural gas produced within the country.

Cheaper fuel costs

And with gasoline costs soaring, the cost advantage of CNG is by far its most attractive feature. Fleet customers may save $2,000 a year or more per vehicle on fuel costs.

Natural gas prices are much less volatile than gas prices, and CNG equivalent to the energy content of one gallon of gasoline costs slightly more than $2 in most areas.

Today, there are fewer than 1,000 natural-gas fueling stations in the U.S., according to the U.S. Energy Information Administration, more than half open to the public. Stations are most prevalent in California, Oklahoma, New York, and Utah.

Gas prices, San Francisco, CA

Gas prices, San Francisco, CA

Full GM warranty

The trucks will be built at GM's pickup assembly plant in Fort Wayne, Indiana, and then trucked 70 miles to Union City, Indiana, where supplier IMPCO will add the gas storage tanks at the front of the bed as well as the fuel delivery system.

The complete vehicle, including all of the natural-gas equipment, is covered under the standard factory warranty, which covers the vehicle for three years/36,000 miles and the powertrain and emissions system for five years/100,000 miles.

Both fuel systems can be serviced as standard factory equipment at the local Chevy or GMC dealer.

That differentiates it from after-market natural-gas conversions for various trucks and commercial vehicles that several companies nationwide offer to fleet customers.

The IMPCO hardware meets the full range of requirements for cold start (down to -40 degrees F), hot-weather running (up to 140 degrees F), corrosion resistance (for 10 or more years), and all Federal safety and crash tests.

Because the 2500 HD versions of the pickup trucks weigh more than 3 tons, GM does not have to provide EPA gas-mileage figures--and it doesn't.

Asked about the fuel economy of the trucks, GM refused to provide numbers, saying only that the gas mileage of the bi-fuel trucks would be "the same as the [gasoline] truck" when running on gasoline.

Orders in April, deliveries Q4

Chevrolet and GMC will start taking orders next month for the dual-fuel pickups, with deliveries before the end of this year. Both trucks are available not only for fleet buyers, but also to retail customers.

Neither brand has released pricing for the new flex-fuel trucks, but the company expects the trucks will provide "a quick return on investment" for their buyers, according to a GM spokesperson.

GM offered natural-gas fueling options for certain vehicles from 1997 to 2006.

Last year, it began offering versions of its Chevrolet Express and GMC Savana full-size vans with both compressed natural gas and Liquefied Petroleum Gas (LPG) powered engines to fleet and commercial customers.

Unlike the new pickup trucks announced today, however, those vans run solely on compressed gas, and do not offer the ability to switch to and from gasoline.


Follow GreenCarReports on Facebook and Twitter.