Photovoltaic panels in the moonroof add to the charge of the batteries and also power pre-heaters for the transmission fluid and diesel fuel, the manufacturer says cuts warm-up times considerably and, in turn, further boosting efficiency. The wheels have sail-shaped spokes designed for efficient ventilation and lower wind resistance.
BMW calls it a “Mild ActiveHybrid,” which means it’s similar in concept to the gasoline-electric systems in large SUVs and pickups from General Motors and the Honda Civic Hybrid.
The Vision EfficientDynamics employs a 2.0-liter clean diesel engine with twin variable-geometry turbochargers and direct injection that produces 204 horsepower and 295 pound-feet of torque. To fully exploit the diesel engine’s relatively narrow rev range, BMW fitted the concept with a new eight-speed automatic gearbox from ZF. Flange-mounted to the transmission is an electric motor-generator powered by a lithium-ion battery pack that spins out an additional 20 horsepower and 155 pound-feet of torque during acceleration.
The bottom line is about 36 mpg combined city/highway with emissions of only 172 grams of carbon dioxide per kilometer (consider that the X5 3.0si returns roughly half as many miles per gallon and emits 244 g/km) blog.wired.com
