http://www.edmunds.com/insideline/do/Features/articleId=105640...
Freymann is no hybrid fan, either. "By having two engines, you simply add weight to the car, and add money to the car. When you drive on the highway, or out of town, the little petrol engine has to lug an inoperative electric engine and a stack of batteries. This is a waste of energy. Only in downtown driving does the hybrid make any sense. Plus the batteries are so inefficient. In all hybrid cars currently on sale, you can only use about 5 percent of the battery power available; that is all. Ninety-five percent always remains in the battery.
"Diesels have more potential. Diesels are fun to drive, fast, less expensive than hybrids and more efficient. The only impediment to diesels selling well in America is pollution regulations [diesels struggle on NOx and particulates]. Mind you, I think diesels will soon peak in popularity in Europe [already 50 percent of cars sold in Europe are diesel]. Direct-injection petrol engines will soon be a widespread reality, and they offer good efficiency and excellent performance."
BMW is working on a gasoline-electric hybrid, but it's a different sort of hybrid. "Ours is lighter, faster and more efficient," says Professor Freymann. Super capacitors, power boosted by regenerative braking, replace batteries. "[The super capacitors] are lighter and store less power, but unlike batteries we can use all their power — all 100 percent." So they give a quick, high-power, short-term "fix" to a small electric motor (mated to a conventional gasoline engine), used only for standing-start acceleration. "An electric engine has a lot of torque at low revs — that is its main benefit — so it's ideal for fast initial acceleration. At higher revs, once you've begun to accelerate, nothing can beat an internal combustion engine. Our hybrid approach combines the best characteristics of both engines."
The BMW philosophy is that these new cars will not just be green; they'll be fun to drive and practical, too. "There's not much fun in driving a current hybrid. We build performance cars. BMWs must continue to offer driving enjoyment. It is absolutely possible to do that and to be eco-friendly."
