Just in time for spiking gasoline prices, Chrysler and General Motors will sell special versions of their heavy-duty pickup trucks powered by compressed natural gas.

The Ram 2500 Heavy Duty CNG, Chevrolet Silverado 2500 and GMC Sierra 2500 join the GMC Savana, Chevrolet Express and VPG MV-1 van as the only commercial-grade production vehicles available with natural gas.

An unusually warm winter and expanded production have continued to drive down prices of natural gas, according to the Energy Information Administration. At the pump, compressed natural gas costs anywhere from $1 to $3 less than an equivalent gallon of regular gasoline. The fuel burns cleaner and emits less greenhouse gas than gasoline.

At the North American International Auto Show in Detroit in January, Chrysler President Sergio Marchionne confirmed the company's intent to sell a natural-gas-powered pickup in the U.S., the first time Chrysler has produced such a vehicle in nine years. While Chrysler is restricting sales to fleets, GM will take private buyers, the automakers told MSN Autos. The Silverado and Sierra pickups will be available in mid-April; the Ram CNG will be ready in July. Both trucks will be available in all 50 states.
The Ram CNG carries two enclosed steel tanks that take up nearly half of the 8-foot bed, which provide the equivalent of 18.2 gallons of gasoline. (For comparison, the Honda Civic Natural Gas can hold only about 8 gallons.) When the estimated 255-mile range evaporates, the Ram switches to a smaller, 8-gallon tank of gasoline without interruption.

The tanks, additional fuel lines and other modified engine components weren't hard to develop. Parent company Fiat sells 80 percent of all natural-gas-powered cars and 55 percent of all natural-gas-powered light commercial trucks in Europe.

Due to the additional weight of the natural-gas tanks, the Ram's payload and towing capacity ratings are down by about 800 and 3,000 pounds, respectively. There's also an $11,000 premium over the standard Ram 4x4 Crew Cab models; the CNG version is available in either ST or SLT trims.

GM would not release pricing but said it would offer the natural-gas option on any extended-cab trim level. The single tank adds 450 pounds and holds less than the Ram's dual tanks, with the equivalent of about 17 gallons of gasoline. GM says the tank, mounted behind the cab, will leave approximately 6 feet of bed space -- about 16 inches more than on the Ram. The GM pickups pack a larger gasoline tank for a total range of 650 miles. GM could not provide estimated payload and towing capacities.

Unlike the federal tax credits given to buyers of electric vehicles, no such incentives exist for natural gas-powered vehicles.

Last summer, Chrysler loaned several dozen plug-in hybrid Ram trucks to municipalities and utilities in select markets, including San Francisco and Boston.

[Source: Chrysler, General Motors]