Hybrid technology has improved fuel economy in “Flex Power” models of the Chevrolet Silverado Fleetside and GMC Sierra Wideside made at General Motors Corp.’s Fort Wayne Assembly Plant.

When the company began making its first hybrid vehicle here late in 2003, it projected the 2-ton, full-size pickups would average up to 18 miles per gallon for city driving, about 13 percent better than the 16 mpg for a conventional pickup.

Highway mileage was pegged at 23.5 mpg, compared with 21 mpg on a conventional pickup.

The first hybrid trucks made were to be sold as fleet vehicles, and GM planned to make them available to dealers this year.

No dealers in Fort Wayne have them yet.

The company had said it planned to offer a revised version of the hybrid pickup featuring its “Displacement on Demand” technology in 2007.

Displacement on Demand saves fuel by using only half the engine’s cylinders during certain driving conditions.

The system automatically reactivates the other cylinders for quick acceleration or load carrying.