DETROIT, MI – Mercedes-Benz shows a rear-wheel-drive hybrid powertrain S-Class concept that it claims gets 30 mpg (8L/100 km) with a V-6 gasoline-fueled engine and two electric motors.

That adds up to a 20% reduction in fuel consumption, says Juergen Hubbert, DaimlerChrysler AG board member in charge of Mercedes cars at the North American International Auto Show here.

The S-Class hybrid has a combined power output of 309 hp and accelerates from 0-60 mph (97 km/h) in about 7.5 seconds, with a top speed of 155 mph.

Mercedes unveils RWD diesel-hybrid S-Class concept.

When idling, parked or in stop-and-go traffic, the 6-seat S-Class concept automatically switches to electric power. One or both electric motors are activated depending on power requirements.

“We are working intensively to develop the RWD-hybrid technology for specific markets,” Hubbert says.

Mercedes also debuts its Vision Grand Sports Tourer (GST) that’s designed for the American market. “We will inspire America with innovations,” Hubbert promises. (See related story: MB Gives Peek at Production GST)

Equipped with a V-8 common-rail direct-injection diesel engine and one electric motor, the GST Vision generates 314 hp and 634 lb.-ft. (860 Nm) of torque. This setup accelerates the cross/utility vehicle from 0-60 mph (97 km/h) in less than seven seconds and still provides 30 mpg.

A Mercedes insider says a production version of the GST will debut here next year, but no decision has yet been made on whether to provide a diesel- or gasoline-hybrid power plant.

Hubbert says the hybrid is bridging technology until fuel-cell vehicles are ready for prime time. That won’t happen until 2010-2012, he predicts.

He also says Mercedes Car Group sold 1, 215,000 vehicles worldwide in 2003. Mercedes set new sales records in North America, Asia and in some European markets, including the U.K, Italy and Spain. Western European sales totaled 811,300 units. Asia/Pacific sales rose 5.6%, to nearly 100,000 vehicles.

Paul Halata, president and CEO of Mercedes-Benz USA, says U.S. sales. increased by 2.6% to 218,700 vehicles. Canadian sales totaled 13,700 units.

Mercedes also reveals Maybach sales for the first time. Hubbert says Maybach sold about 600 units worldwide last year, one-third in the U.S. Halata forecasts Maybach sales will reach 400 units in the U.S this year, out of 1,000 sales worldwide.