BMW has joined the hybrid party with the introduction of a 7 Series hybrid concept car which will be shown at next month’s Paris motor show.There we will see Mercedes-Benz and BMW go head-to-head in the hybrid stakes, with both carmakers scheduled to unveil advanced petrol-electric versions of their respective flagship saloons at the upcoming show. Mercedes released the first details for its S400 BlueHYBRID last week, and confirmed the car for a mid-2009 launch date.
BMW has already recently introduced several other hybrid concepts, including the two-mode Concept X6 ActiveHybrid and the diesel mild hybrid concept BMW Vision EfficientDynamics. BMW says that it is developing hybrid technology along various lines for various vehicle segments, and that pursuant to this strategy, two models with BMW ActiveHybrid technology will be reaching production level in 2009.
While Mercedes’ S400 BlueHYBRID features an electric drive system mated to a 3.5L V6 powerplant, BMW’s new Concept 7-Series ActiveHybrid is based around the 4.4L V8 750i model. The concept car features the standard 407hp (303kW) and 442lb-ft (600Nm) V8 powerplant mated to a 20hp (15kW) and 155lb-ft (210Nm) electric motor. Other standard hybrid features, such as regenerative braking, automatic stop-start and optimized aerodynamics, are also present on the 7-series ActiveHybrid concept.
The two turbochargers are fitted directly in the V-section of the engine, with each unit supplying four cylinders with compressed air to support quick response to the accelerator pedal. High Precision Injection is the second generation of direct gasoline injection introduced by BMW incorporating piezo-injectors fitted in the cylinder head directly next to the spark plugs and delivering fuel to the combustion chambers at a pressure of 200 bar.
Compared with the non-hybrid model, the new ActiveHybrid is said to improve fuel-economy by up to 15%. Mercedes, meanwhile, claims that its S400 BlueHYBRID runs 21% more efficiently than the standard S350. Both cars will feature lithium-ion battery systems, though Mercedes is planning to be the first carmaker in the world to market with such a system in a mass-produced vehicle.
The new 7-series hybrid will feature BMW’s version of the modular two-mode hybrid system jointly developed with Daimler, Chrysler and General Motors. The system features a pair of electric motors located within the transmission and can provide electric only drive at low speeds or act as a performance booster at high load.The electric motor develops maximum output of 15 kW/20 hp and peak torque of 210 Nm (155 lb-ft).
The BMW Concept 7 Series ActiveHybrid uses electrical energy to an even higher degree for additional functions beyond the power provided by the electric motor in support of the car’s primary drive system. A 120V on-board network serves to meet further purposes and requirements, operating in parallel to the conventional 12V network powered by an AGM lead-acid battery.
While the Paris show car remains a concept only, the production 7-series hybrid is expected to go on sale late next year or in early 2010.