ST. LOUIS -- General Motors Co. plans to offer full-sized trucks powered by compressed natural gas.
Van, pickup and chassis cab models are expected to be available in about two years.
"A number of fleet operators want to present a green presence to the public," said Rick Spina, the vehicle line executive who oversees GM's full-sized trucks.
"They want to be known as green companies," especially those on the retail side, Spina said here this month at the National Truck Equipment Association's Work Truck Show.
According to news reports, AT&T Corp. is adding as many as 8,000 vehicles that run on compressed natural gas -- primarily Ford E-250 Econoline vans.
Spina said the conversion can be made with few changes to the engine.
"We have to harden the valves, harden certain things for durability reasons," he said. But "pretty much it is a gasoline engine." The transmission needs to be recalibrated because the power curve is different.
GM has yet to determine whether it will do the complete conversion, farm it out to another company or let the fleet operator find a converter. Roush Enterprises, a Detroit area engineering company, does Ford's conversions.
On a gasoline-equivalent basis, the fuel economy of a natural-gas vehicle is slightly lower than that of a comparable gasoline-powered vehicle.
"If you got 20 mpg, maybe you get 19 mpg on CNG," said Ford spokeswoman Jennifer Moore. "But overall, there is an advantage in operating cost because of lower natural-gas prices."
Chrissie Thompson contributed to this report