General Motors' Buick brand will launch a crossover with plug-in hybrid system in 2011, a year after the mainstream models arrive with new, fuel efficient direct injected petrol engines.

Announcing the new line at this week's auto industry seminars in Traverse City, Michigan, Tom Stephens, GM's product development head, said he expected the as yet unnamed vehicle would be the first commercially available plug-in hybrid SUV produced by a major automaker.

Buick said the plug in hybrid version could achieve up to double the fuel economy of comparably-sized SUVs on short trips. It will combine a modified version of GM's current two mode hybrid system with lithium-ion battery cells and Voltec charging technology developed for the Chevrolet Volt extended range EV due on sale late in 2010.

"LG Chem - the supplier of our battery cells for the Volt - has also been selected to supply the lithium-ion cells for the new Buick plug-in hybrid, and its Troy, Michigan based subsidiary Compact Power will supply the pack," Stephens said.

The Buick plug-in will use the same manganese-spinel based chemistry and polymer battery cells as the Volt. The 8kw/h battery - containing half the energy of the Volt battery pack - will be packaged in a rectangular-shaped box under the cargo floor.

The lithium-ion battery can be fully recharged in four to five hours by connecting the vehicle to a standard 110 volt US household electrical outlet.

Initial testing has shown the plug-in hybrid is capable of electric-only propulsion for over 10 miles (16km) at low speeds, Stephens said.

"Buick has always been at the forefront of new technology, so it is only fitting that the brand should debut our new plug-in hybrid technology in a beautiful new crossover," he said. "This will firmly put Buick, and GM, front and centre in the advanced technology game."

Stephenson said the new five passenger crossover would be smaller than the current Enclave.
"Some customers who have been drawn to the Enclave were looking for something a little smaller, but they didn't want to give up craftsmanship or a quiet ride to get there," said Susan Docherty, general manager of Buick-Pontiac-GMC. "We believe this new Buick will excite those customers, and will continue to broaden the appeal of the brand."

The new crossover will offer a standard 'Ecotec' 2.4 litre direct-injected I4 engine and an optional three litre, direct injected V6, expected to deliver about 30 miles per [3.9 litre US] gallon in highway driving.

GM already offers hybrid SUVs such as the giant Chevrolet Tahoe and the mid size GM Daewoo design based Saturn Vue. Rival offerings include Ford's Escape Hybrid and its Mercury branded clone.