By Barbara Kessler

General Motors announced today that it will be using a new, improved advanced lithiu2008_saturn_vue_green_line_hybrid.jpgm-ion battery for its hybrid models starting in 2010 in North America – a move that could raise the fuel economy of those hybrid cars and trucks using the system by up to 20 percent, depending on the engine and vehicle use.

Translation: A $50 tank fill up could become a $40 tank for consumers, while the Earth’s atmosphere gets a break too.

The next generation “GM Hybrid System” will be used in a wide range of global powertrains, including naturally aspirated engines, new high-efficiency turbocharged engines, bio-fuel engines and diesels. It will reduce emissions and increase fuel efficiency by turning off the engine while the car is idling; providing sporadic electric-only power; enhancing engine efficiency via the electric motor; extending fuel cutoff during deceleration and using regenerative braking to recapture more energy, according to the GM news release.

Those techniques were largely pioneered by Toyota with its top-selling Prius hybrid car, but are becoming the staples of hybrid technology. GM has greatly increased its investment in such green endeavors, promising to offer hybrid models in North America by the end of 2008.

GM announced the new technology at the 78th International Geneva Motor Show, with GM Chairman Rick Wagoner declaring that the improvements will “have a real impact in reducing oil consumption, oil imports, and CO2 emissions” while also remaining affordable. Indeed, the current GM hybrid system, debuted in 2006, is used in the Saturn Vue Green Line SUV, which GM boasts is the lowest price hybrid SUV on the market with a $25,995 retail price tag.

The Saturn SUV gets about 25 mpg in the city and 32 on the highway, according to EPA estimates.

GM’s new hybrid battery (produced by Hitachi Vehicle Energy Ltd.) is being tested in a smaller car, a prototype SAAB 9-X BioPower Hybrid, which is projected to get 48 mpg on average.

Detroit-based GM, the world’s largest automaker, employs about 266,000 people around the globe.