INDIANAPOLIS -- General Motors announced details on the eve of The Work Truck Show of a bi-fuel engine that will be available late this year in 2013-model Chevrolet Silverado and GMC Sierra 2500 HD extended cab pickup trucks.

Fleet and retail consumers can place orders beginning this April.

The vehicles include a compressed-natural-gas-capable Vortec 6-liter V-8 engine that transitions smoothly between CNG and gasoline fuel. The two fuels combined give the trucks a range of more than 650 miles. The Silverado and Sierra will be available in standard and long box, with either two- or four-wheel drive.

GM will build the gasoline-CNG trucks with a specially designed engine in Fort Wayne, Ind., and send them to a Tier One supplier who will install the fuel system. The completed vehicle will go directly to the customer. This process makes ordering the bi-fuel option as easy as a standard vehicle, executives said.

"The bi-fuel truck provides businesses with added re-fueling flexibility and eases consumer range concerns that typically come with CNG, all while reducing emissions and controlling costs," said Joyce Mattman, director, GM Commercial Product and Specialty Vehicles.

"This turnkey ordering process, combined with the best warranty in the industry for a commercial product, makes our bi-fuel truck an attractive option, especially for commercial customers."

The bi-fuel commercial trucks will be covered by GM's three-year, 36,000-mile new vehicle limited warranty and five-year, 100,000-mile limited powertrain warranty and vehicle emissions warranty, meeting all federal and California emission certification requirements. GM claims it is the most extensive warranty offered by any manufacturer on commercial products.

More information is available at www.gmfleet.com.