Some of the largest pickups and sport-utility vehicles will soon come in hybrid versions as automakers bet that consumers want to save fuel without compromising capability. Chrysler showed its first two hybrids - both SUVs - last week at the Los Angeles Auto Show, while General Motors unveiled its hybrid Chevrolet Silverado pickup. Even the mammoth Cadillac Escalade is getting a hybrid option, and its Hummer models have been available in hybrid for a couple of years.

But with efficiency comes a price. Although specific numbers aren't being released yet, the new hybrids will cost more than models with conventional engines. And industry analysts are wondering just how much demand there will be for the new power systems.

''Americans shouldn't have to choose tiny little vehicles to get fuel efficiency. We ought to be able to offer a range of choice while still being sensitive to environmental impact,'' Mark LaNeve, General Motors vice president of North America sales, service and marketing, said during a media preview last week in Detroit.

The big hybrids were one story at the show, which often is a showcase for automakers' greenest ideas. Honda introduced a hydrogen fuel-cell car that will be marketed to consumers next year. Hyundai showed off the QarmaQ concept car, which is made from recycled plastic bottles.

It's unclear how much demand there is for full-sized hybrids, said Mike Omotoso, senior manager of global powertrain forecasting for J.D. Power and Associates. Omotoso predicts about 10 percent of customers buying large SUVs would choose the hybrid option. Overall, hybrid sales are expected to reach 300,000 this year, or about 2 percent of all U.S. sales, according to R.L. Polk and Co., an auto information and marketing company.

A hybrid system developed by GM, Chrysler, Mercedes-Benz and BMW will debut on 2009 models of the Chrysler Aspen, Dodge Durango Hemi, the Silverado and the Escalade. The automakers say the hybrid system - called a two-mode hybrid - improves fuel economy by at least 25 percent. For the Silverado, which now gets 15 miles per gallon in the city, that could mean an improvement to 21 miles per gallon, similar to the Toyota Camry in city driving.

The system can operate in electric-only mode at low speeds or with a combination of the gas engine and electric assistance at higher speeds. Like single-mode hybrid systems now used by Toyota, Ford and others, the two-mode runs without the gas engine at low speeds, but at higher speeds the electric motor contributes more power. Single-mode systems also have heavier motors, making them less ideal for towing.

Hybrid versions of the Chrysler Aspen and Dodge Durango SUVs are scheduled to arrive in showrooms in the middle of 2008, Chrysler said. The SUVs can use an engine-only mode when conditions demand the full power of the 5.7-liter HEMI V-8 engine, such as climbing a steep hill or pulling a trailer. The Aspen and Durango are capable of towing 6,000 pounds.

Chrysler wouldn't say how much the hybrid Aspen and Durango will sell for, but there will be a premium.

GM already has introduced the two-mode hybrid system in its Chevrolet Tahoe and GMC Yukon SUVs, which will be available in early 2008. The 2009 Silverado will be the first full-sized, full-hybrid pickup on the market when it goes on sale at the end of 2008.