BMW has divulged all the details on the ActiveHybrid 5, a new hybrid luxury sedan based on the existing 535i. The car is the first BMW hybrid to employ an inline-six engine. We had long expected the arrival of this car, and had even spied a prototype version testing in California.
The ActiveHybrid employs the same direct-injection, turbocharged 3.0-liter inline-six engine as the 535i, producing 300 hp and 300 lb-ft of torque. It is coupled to an eight-speed automatic transmission which has an integrated electric motor/generator. The motor is rated for 55 hp and 155 lb-ft of torque, and stores electrical energy in a trunk-mounted lithium-ion battery pack. The combined peak power output of the engine and motor is 335 hp.
BMW doesn’t have any fuel economy estimates for the ActiveHybrid 5, although a 2011 535i is rated at 20/30 mpg (city/highway) with the eight-speed automatic transmission. The car will be able to travel on electrical power alone up to 37 mph, or for about 2.5 miles at an average speed of 22 mph. The car can reportedly hit 60 mph in 5.7 seconds. As with all hybrids and many modern non-hybrids, engine stop-start technology is standard.
The car’s navigation system is linked to the hybrid drivetrain and attempts to optimize the engine and motor for the route. For instance, BMW says the hybrid system might use lots of the battery’s charge to help propel the car up a hill, then allow the battery to be fully recharged as the car drives down the other side of the hill. The system also will try to ensure the battery is fully charged as the driver approaches the end of a journey, so that parking and other low-speed maneuvers can be performed solely on electrical power.
There also is an ECO PRO driving mode, which further adjusts the engine and transmission to consume as little fuel as possible. In this mode, the gasoline engine can be switched off and decoupled from the driveline at speeds of up to 100 mph when the ActiveHybrid 5 is coasting, helping save fuel at highway speeds.
BMW has yet to release pricing or fuel-economy figures for the ActiveHybrid 5. The car goes on sale in the U.S. in March 2012.