The next BMW M5 will get a version of BMW's Formula 1-developed KERS system. KERS, which stands for Kinetic Energy Recovery System, is a technology whereby the energy generated from braking is reused to help "power" the vehicle.
The regenerative braking system will use the electricity to help power electrical aspects of the car (and thereby reduce the strain that alternator and accessory belts would have on the engine). The stored energy will also be harnessed and made accessible to the diver for enhanced acceleration through a "boost" button. The next M5 is also expected to feature cylinder deactivation for city driving.
Word of a regenerative braking system comes from a BMW insider Scott27 on The German Car Zone.
As for the powertrain of the next M5, code named F10, there are two current speculations. The first is that it will get a version of the 550hp, 4.4-liter V8 used in the BMW X5 and X6 M, but there have also been several rumors that a V10 powerplant based on that same architecture is a possibility. Based on BMW's Efficient Dynamics approach we expect to see a smaller engine than the current 5.0-liter V10, with turbochargers.
More: Next BMW M5 to Get Regenerative Braking System