BMW has released initial details for its 7-Series ActiveHybrid Concept which will make its world debut in Paris. Described as a mild hybrid, the 7-Series uses a small electric motor, developing 15 kW/20 hp and peak torque of 210 Newton-metres/155 lb-ft., integrated in the transmission housing essentially replacing the drag inducing auxiliary components such as the alternator and starter motor. Electrical energy is generated through Brake Energy Regeneration system and stored in a high-performance lithium-ion battery located in the luggage compartment. In this mild hybrid setup, the positioning of the electric motor in the transmission aids in the efficiency of the auto start/stop function.
Additionally, the energy yield produced by the electric motor through Brake Energy Regeneration alone exceeds normal standards by roughly ten times. Such electrical power output provides ample energy to run auxiliary components such as air condition and infotainment systems and not off the alternatorwhich draws energy directly from the combustion engine reducing its overall efficiency.
The engine is based on the N63 direct injection 4.4-liter twin-turbo V8 unit already seen in the 750i and X6 xDrive50i producing 300 kW/407 hp, with peak torque of 600 Newton-metres or 442 lb-ft. In mild hybrid form, the result is 15 percent less fuel consumption and emissions (in the EU test cycle) versus a combustion engine only equivalent. BMW plans to start production of two models with ActiveHybrid technology in 2009.
