New BMW 7-series hybrid uses lithium, still won't match efficiency of diesel

When BMW launches a hybrid version of the new 7-series sedan next year it looks like it will probably use the same Two-Mode hybrid system going into the X6 crossover. That configuration mates the hybrid transmission with the twin-turbocharged 4.4L V-8 that also debuted this spring in the X6. If Britain's CAR magazine is right, this may also be the first of the Two-Mode hybrids to use a lithium ion battery. All the existing Two-Modes from GM and Chrysler are still using nickel metal hydride. One thing the hybrid system apparently won't be able to do is approach the mileage of the diesel engine in the 730d that will be available at the new luxury sedan's launch. According to Dr. Klaus Draeger, BMW board member responsible for R&D, the 7 series hybrid is targeted at fans of V8s who want a bit of green image rather than those that actually want the lowest fuel consumption. For those that want to save at the pump, the 6 cylinder diesel with its combined mileage rating of 32.6mpg (U.S.) is the way to go. The V8 hybrid is likely get closer to the 20mpg of the Lexus LS600h as well as being a lot more expensive.

[Source: CAR]