BMW Planning 5 Series ActiveHybrid

Mild Hybrid System Coming for New 5 Series

BMW will install a version of its new ActiveHybrid mild hybrid system -- featured in the 7 and 6 Series -- into the all-new BMW 5 Series. The system features an electric motor sandwiched between the V-8 motor and the eight-speed transmission, and a lithium-ion battery in the trunk.

On the 7 Series, the ActiveHybrid system improves performance versus the 750i, reducing the 0-60 time to approximately 4.8 seconds, while offering about 15-percent better fuel economy. Other advantages include an idle-stop system, which makes town driving more peaceful, and an electrically driven air-conditioner that can run for 30 minutes without the engine.

BMW sources say the hybrid system can be added to a car for about €5000 ($7500). The gap between the 7 ActiveHybrid and the standard 750i is greater than that, but the feature content of the hybrid is higher.

It is for cost reasons that BMW has no plans for a diesel hybrid – clean diesels are expensive engines. Diesels are in any case economical at light load, which is the mode where a gas engine needs the help of hybrid. Also, the company is currently selling in Europe a 3 Series diesel with 163 horsepower and 8.2-second 0-62 mph performance that matches the Mk2 Toyota Prius for CO2 emissions. An engineer explained that hybridizing such a car would add several thousand dollars to its cost while saving the driver just $150 a year, even at Europe’s high fuel prices.