X3 uses high-performance capacitors ("Super Caps") to store and supply electric energy to the vehicle's well-packaged "Active Transmission." The Active Transmission combines an electric motor with the functionality of a conventional six-speed automatic gearbox, and attaches directly to a BMW straight-six gasoline engine that employs jet-guided direct injection to further increase efficiency.
The hybrid package is said to be good for up to 440 lb-ft of torque, with 295 lb-ft coming from the 80-hp electric motor. BMW chairman Dr. Helmut Panke noted that "while this vehicle won't go into production in this form, it does provide a preview of possible future developments." Make that "probable," since BMW announced in the fall of 2005 that it was joining forces with General Motors and DaimlerChrysler to develop hybrids, a collaboration scheduled to bear product fruit in the 2008 model year.
If BMW does end up building the X3 hybrid, it would be cool (though likely spectacularly unsafe) to retain the badge-of-hybrid-honor side sill treatment, which shows off the copper red Super Caps themselves (see photos).