General Motors has fingered one basic model for its bi-fueler: a 2500 HD Extended Cab, though it can be had with a short or long box and two- or four-wheel drive. It’ll be sold as a Chevrolet Silverado or GMC Sierra. The trucks will be produced in Indiana: They’ll emerge from GM’s Fort Wayne plant with a gas-prepped Vortec 6-liter V-8 and travel to nearby Union City, where IMPCO Automotive will install the CNG equipment.
GM people emphasize that this is not an “upfit,” because IMPCO is a Tier One supplier whose precise manufacturing processes are in synch with GM’s. IMPCO will install the Bosch CNG fuel system and mount the tanks in the bed. The tanks will be in special cabinet that’s attached to the frame, not the bed floor. The system has been rigorously tested for starting and running in very cold and hot temperatures and at high altitudes. And the truck has been crash-tested multiple times to ensure integrity of the gas system.
The Vortec engine starts on gasoline only and will run on either fuel; it will not start on CNG. Although CNG is the preferred fuel, the natural gas tank holds 17 GGEs and the gasoline tank holds 36 gallons; together they give a 650-mile range.
The CNG tank has an aluminum liner and a composite wrap for strength. The CNG system weighs 450 pounds, which is subtracted from the truck’s payload. It will tow 9,500 to 15,000 pounds. GM is now taking orders on the bi-fuel system, but had not finalized pricing at our press time. Production starts late this year.