GENEVA, SWITZERLAND – BMW unveiled a diesel-electric hybrid concept version of its X5 SUV, and claimed that its efficient dynamics program is saving huge amounts of fuel, according to www.detnews.com. The X5 concept car has a four-cylinder 2.0L, twin-turbo diesel engine, which produces 204 bhp but still manages to return around 40 miles to the U.S. gallon.

This X5 has a stop-start system, which automatically switches off the engine when the car stops in traffic and turns it on again when the accelerator is depressed. Power generated while the vehicle is coasting is also captured and fed into the battery. Solar panels on the roof use power to heat fluids like diesel fuel to curb wasteful emissions, which cold starts generate. The eight-speed automatic gearbox makes sure the best gear for economy is always available.

Efficient dynamics, which includes stop-start and power recovery from coasting, will be fitted to about 700,000 BMWs this year.