Today General Motors said its Chevrolet and GMC dual-fuel extended-cab pickups will retail for $11,000 above comparable Silverado and Sierra HD 2500 three-quarter-ton models.

The trucks, powered by 6.0-liter Vortec V8 engines are able to run on gasoline or compressed natural gas. Although the latter requires a separate fuel tank, GM says the Type 3 unit employed on the Silverado and Sierra HD bi-fuel models is a lightweight unit designed to maximize cargo space and payload capacity, resulting in better bed volume than rival pickups.

Both trucks are available in 4×2 and 4×4 configurations, meet all EPA and CARB emissions requirements and will come with GM’s standard three-year 36,000-mile bumper-to-bumper and five-year 100,000-mile powertrain warranties.

While compressed natural gas vehicles have long been utilized by some commercial fleets notably large taxi companies, until recently it was rare to find CNG vehicles in use by others such as car rental agencies and small businesses or contractors.

However, with higher fuel prices and economic realities, that’s starting to change, as CNG offers numerous benefits for fleets, such as good availability and low price. According to GM’s Commercial Product and Specialty Vehicle director Joyce Mattman, unit costs are around half that of gasoline – presently averaging around $1.89 per gallon – and can be adapted to existing vehicle technology without huge investment.

GM’s new HD bi-Fuel trucks are built at the Ft. Wayne, Indiana truck plant alongside other HD models and then shipped to a Tier 1 supplier for installation of the CNG fuel tank and system components.