General Motors finally seems to have found a role for Saturn, its 'alternative' brand, launched in 1991 in a bid to appeal to younger buyers.

"Saturn has become GM's green brand," said Troy Clarke, GM's president of North American operations.

Three eco-friendly Saturn models were unveiled at Detroit. The most significant is a plug-in hybrid version of the Vue SUV, which could become the first commercially available GM electric car as early as 2010 - possibly even before the Chevrolet Volt.

The Vue's lithium ion battery pack will give a range of only 10 miles as a pure EV - less than the Volt, which has an all-electric range of around 40 miles.

A dual-mode hybrid Vue Green Line was also revealed. With a petrol-electric powertrain using nickel-metal hydride batteries for low-speed all-electric operation, Clarke said it was the world's most fuel-efficient SUV.

"It is 50% more fuel-efficient than a standard, non-hybrid Vue," he said.

A test fleet will be on the roads by the fourth quarter of 2008, with customer deliveries following shortly afterwards.

The third Saturn reveal was the Flextreme concept car - "the next evolution" of the plug-in hybrid, said Clarke, with a potential 35-mile all-electric range. Developed jointly by Saturn and Opel, it'll form the basis of future European hybrid GM models too. It uses GM's E-Flex system, incorporating an integrated 1.3-litre turbodiesel engine, electric motors and Li-Ion batteries.

The entire Saturn range has been renewed in the past 20 months, largely through adapting versions of European Opel/Vauxhall models such as the Astra and Vectra.

Sales rose 20% in 2007 and higher-value models meant the average transaction price for a Saturn car rose 43% over 2006.

Clarke couldn't resist a pay-off pun: "Saturn is plugged in to the demands of its customers - and buyers are plugging in to Saturn," he said.