BMW has just given out info on two of the company’s upcoming hybrids cars based on the X6 and the 7 Series. These hybrids, unlike many out there, are no slouches in the power department and can put over 400 horsepower to the pavement. Of course, they also have better fuel economy than their gasoline-only counterparts. Jump for the details on these BMW “ActiveHybrid” cars. [Source: BMW]

The ActiveHybrid X6 is powered by a 4.4 liter twin turbocharged V8 engine that produces around 400 horsepower. Pretty good already, but weak compared to the X6 M, which is rated for more than 550 hrosepower. The hybrid will also have two electric motors that are rated at 91 horsepower and 86 horsepower for a total output of 480 horsepower and 575 lb-ft of torque – not bad for a car with low emissions. Fuel consumption will be reduced by 20% but no exact figure was mentioned.

More importantly, the ActiveHybrid X6 is able to run on its electric motors all the way till 37 MPH, using only one electric motor. Once higher speeds are reached or more power is needed, the second electric motor will start up the gasoline engine. Of course, it will have a kinetic energy recovery system that feeds its nickel metal hydride battery pack while braking or decelerating.

Power is transmitted through a seven-speed automatic transmission with four clutches and three planetary gearsets. All four wheels are powered thanks to BMW’s xDrive system.

News on the ActiveHybrid 7 Series was released very close to the X6 hybrid, but it’s actually powered by a different system. It also uses their 4.4-liter turbocharged V8 engine but it produces 440 horsepower in this application. A single electric motor between the engine and transmission is rated at only 15 to 20 horsepower. It might end up being more efficient then the X6’s electric motors because the ActiveHybrid 7 uses lithium-ion batteries instead of the more common NiMH packs.  Expect a 15% reduction in fuel costs when compared to a gasoline 7 Series sedan.

While the 7 Series might be the flagship hybrid model, the X6 hybrid looks like a much more attractive buy. It’s looks are still questionable but it’s ability to purely accelerate up to 37 MPH with its electric motors, yet still able to drop the hammer with the gas engine, would make urban driving much more efficient while still being fun to drive.  More green cars should start following that formula.

Expect to see more on these cars at the upcoming Frankfurt Auto Show.