The ActiveHybrid 5 is expected to be inspired by the 2010 BMW ActiveHybrid 7 which is its full size sports sedan on the hybrid luxury class. The 7-Series uses a 3-phase electric motor which is linked to the crankshaft of the car’s V-8 gasoline engine paired with new 8-speed automatic transmission.

The 5-Series will be a mild hybrid. This means that the car will not run relying on the electric engine alone like the 2010 BMW X6 ActiveHybrid. What it will do is utilize the electric motor to restart the gasoline engine after it turns off during stops. The electric motor will also add more torque to help the gasoline engine.

In the 7-Series, the combined output of the electric motor and the gasoline engine is 455 horsepower with a good torque at 516 lb-ft. The bigger ActiveHybrid-7 can zoom from 0 to 60 mph in 4.8 seconds but still it offers a 15% better fuel economy than the powerful 750i.

The announcement of the ActiveHybrid-5 release this March confirms that earlier disclosure of plans of the carmaker. The carmaker sees the potential of the 3-,5-, and 7-Series to become mild hybrids. This opens the possibility of an ActiveHybrid-3 any time soon.

It is not yet clear if the ActiveHybrid-5 will be released along side the 2011 5-Series due for roll out in the US by fall or if it will be marketed as a 2012 model.