GM has announced at the LA Auto Show that it intends to produce a Saturn Vue Green Line plug-in hybrid that it claims 'has the potential to achieve double the fuel efficiency of any current SUV'.

The hybrid SUV will use a modified version of GM's 2-mode hybrid system and plug-in technology, a Lithium Ion battery pack when ready, along with 'highly efficient electronics and powerful electric motors to achieve significant increases in fuel economy'.

"GM has begun work on a Saturn Vue plug-in hybrid production vehicle," said Rick Wagoner.

"The technological hurdles are real, but we believe they are also surmountable. I can't give you a production date for our plug-in hybrid today. But I can tell you that this is a top priority program for GM, given the huge potential it offers for fuel-economy improvement."

A plug-in hybrid-electric vehicle differs from non-plug-in hybrid-electric vehicles by offering extended electric-only propulsion, additional battery capacity and the ability to be recharged from an external electrical outlet.

The Saturn Vue Green Line plug-in hybrid is expected to offer electric-only propulsion for more than ten miles, GM says.

At higher speeds or when conditions demand it, such as brisk acceleration, a combination of engine and electric power or engine power only will propel the vehicle.

In addition to plug-in capabilities and the modified 2-mode hybrid system, the Saturn Vue Green Line hybrid SUV's powertrain will feature Lithium Ion battery technology, two interior permanent magnet motors and GM's 3.6L V-6 gasoline engine with direct injection.

When ready for production, the Lithium Ion energy storage system will be replenished when the battery charge is depleted to a specified level by utilizing the 2-mode hybrid system's electric motors and regenerative braking systems. When the vehicle is parked, the battery can be recharged using a common household exterior (US) 110-volt plug-in outlet.

The 2-mode hybrid system will be altered for use with plug-in technology. It maintains two driving modes - one for city driving, the other for highway driving - and four fixed mechanical gears to maximise efficiency while maintaining performance. In addition, special controls will be utilised to enable higher speeds during electric-only propulsion and maintain electric-only propulsion for longer periods of time.

The Saturn Vue Green Line SUV, featuring the modified 2-mode hybrid system with plug-in capabilities, is part of GM's effort to offer consumers a broad choice of hybrid systems at various levels of affordability.

The first front-wheel-drive application of the 2-mode hybrid system will debut - without plug-in technology - in the Vue Green Line in 2008.