Based on the 535i, the ActiveHybrid 5 marks the third production hybrid from BMW, though it will be one of only two on sale (the other being the ActiveHybrid 7) soon as the ActiveHybrid X6 ceases production.
The hybrid system offers all-electric power up to 37 mph and pairs with an eight-speed automatic transmission. Being based on the 535i, the ActiveHybrid 5 also sports a twin-scroll turbocharged 3.0-liter inline six-cylinder engine. The combined output is closer to the 335is, however, at 335 horsepower, and acceleration is punchy for any sedan, let alone a hybrid, at 5.7 seconds to 60 mph. Those figures put it in the same league with--but slightly behind--the Infiniti M35h.
As you'd expect from BMW, that's not the end of the story. The automaker has added a host of other tweaks, both computerized and hardware, to help ensure the hybrid maximizes its efficiency. Those include: regenerative charging of the lithium-ion battery during coasting and braking; a start-stop system; an ECO PRO driving mode that relaxes throttle response and shifts and also cuts the engine during coasting at speeds of up to 100 mph; integrated navigation to select the most efficient route; and more. Basically, it has all of the features of the ActiveHybrid 7's driveline, but mated with a six-cylinder instead of a turbo V-8, and with a more powerful electric motor that enables limited all-electric driving.
BMW says the ActiveHybrid 5 has a maximum all-electric range of up to 2.5 miles at an average speed of 22 mph. That's not a lot in comparison to full-electrics, but it's fairly substantial for a hybrid. BMW hasn't yet released estimated fuel economy figures, so we can't judge just how effective the whole package is.
We'll keep you updated as the March, 2012 sales release draws nearer. In the mean time, you can compare the production car's stats to the concept's here.