This prototype doesn’t have the lowered front fascia and wild wheels used on the Concept ActiveHybrid 5 Series, but we’re fairly certain there’s a hybrid powertrain lurking under the skin. The prototype wears a sticker reading “RESCUE Remove in case of emergency.” The last time we saw such a sticker affixed to a BMW prototype was a test mule for the X6 ActiveHybrid crossover.
Unlike the X6’s hybrid system, the ActiveHybrid 5 will use BMW’s latest turbocharged 3.0-liter I-6 as its gasoline engine. A 40-kW (54 horsepower) electric motor is sandwiched between the six-cylinder and an eight-speed automatic, allowing it to propel the sedan on its own at low speeds, work in conjunction with the 300-horsepower engine, or serve as a generator to recover energy during braking. BMW claims the configuration will boost fuel economy by about 10 percent.
Source: Motor Trend