In the 2005 model year, GM offered the hybrid versions of the Silverado and Sierra in just six states -- Alaska, California, Florida, Nevada, Oregon and Washington -- to test the market. GM sold all 2,000 of the hybrid trucks it built in the initial production run.
The $1,500 hybrid option is available only on the Silverado 1500 and Sierra 1500, or light-duty versions. Those trucks' prices start at $33,050, including shipping.
But GM is offering rebates of between $4,000 and $5,500 on leftover 2005 models and $1,000 to $3,000 on 2006 models.
Richards said GM plans to build 3,000 of the hybrid trucks for the 2006 model year. Production can go higher if the demand is there, said Richards.
GM's hybrid trucks are powered by a 5.3-liter V-8 engine and a 14-kilowatt electric motor.
The motor is sandwiched between the engine and transmission in the area where the torque converter is normally found. It provides a gentle boost under heavy acceleration that helps smooth the shifting of gears in the transmission.
The gasoline engine turns off when the vehicle comes to a stop; the electric motor starts it automatically when the driver takes his or her foot off the brake pedal.
GM says the hybrid trucks deliver 10 percent better fuel economy than the standard models with the same size V-8 engine, giving them an EPA rating of 18 mpg in the city and 21 mpg on the highway.