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September 23, 2008 5:29 PM PDT

BMW builds luxury hybrid sedan

by Wayne Cunningham

BMW Concept 7-series ActiveHybrid

BMW's 7-series concept uses a mild hybrid powertrain.

(Credit: BMW)

Following on the recent announcement by Mercedes-Benz of its mild hybrid sedan with lithium ion batteries, BMW announced its own mild hybrid sedan with lithium ion batteries.

Although it may sound like cutthroat competition, it's more conspiracy, as Daimler and BMW co-developed their hybrid components. And where Mercedes-Benz announced a production car, BMW is still at the concept stage with its Concept 7-series ActiveHybrid. But in keeping with its sport aspirations, the BMW shows no compromise in power, using a twin-turbo V-8 assisted by the mild hybrid system. The twin-turbo V-8 delivers 407 horsepower and 442 pound-feet of torque, while the hybrid system's electric motor, integrated into the transmission, adds 20 horsepower and 155 pound-feet of torque.

BMW Concept 7-series ActiveHybrid engine

The hybrid system was co-developed by Daimler and BMW.

(Credit: BMW)

As a mild hybrid, the Concept 7-series ActiveHybrid can't run under electric power alone--the electric motor merely adds thrust when needed and is an essential part of the idle-stop system. At a traffic light, the engine shuts down to save gas, with the electric motor cranking it back up when the driver hits the gas, and adding its power to make up for the initial shortcoming of the engine. BMW claims a 15 percent improvement in fuel economy.

The lithium ion battery pack sits over the rear axle, and gets recharged through regenerative braking. Along with providing electricity for the motor, this battery pack works as a 120 volt power source for the car's onboard electronics.

BMW has previously shown the X6 ActiveHybrid concept, an SUV using a full hybrid system based on technology co-developed by BMW, Daimler, and GM. We first saw a version of that hybrid system in the GMC Yukon Hybrid. BMW promises two cars using some form of its hybrid technology will reach production in 2009. The company might want to hurry up, as Lexus already dominates the segment for powerful luxury hybrid sedans with the LS 600h.

BMW ActiveHybrid diagram

The electric motor is integrated with the transmission.

(Credit: BMW)

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by molotov September 25, 2008 8:35 AM PDT
It is time for both Mercedez-Benz and BMW to step it up and standardize the V-12 engine. Clearly they have the technology and the only available V-12 options are on super-souped up editions of their vehicles, like the M5; which offers V-10.
BMW and M-B should both realize that the only people that drive their cars are egomaniacs with pockets full of money. Among other, more harrowing things, the drivers of these two spledidly expensive marques do not care about the environment, but neither does China. So what?
Give the customers what they want; big engines. These engines are to reward the driver with disproportionate amounts of horse power and insane torque. This will boost the drivers' already inflated egos and thus create the new 'BMW driving experience' or 'Mercedes-Benz thrill.'
The rest of us will have to drive small, inline 4-cylinder, hybrid cars to compensate for their driving experiences and thrills. Much like our current economic situation. But that's a whole different ball game. In conclusion; skip the hybrid stuff 'Bimer. SOHO, NYC.
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