At the rear axle is BMW's Active M Differential, which can vary the torque split between the rear wheels for maximum grip. It works in tandem with the stability control system to determine how much power should be sent to each wheel -- it can shuffle anywhere from zero to 100 percent of engine torque to either of the rear tires. The trick diff is said to reduce understeer, provide better high-speed stability, and improve cornering performance.
Like any self-respecting manufacturer of sports cars, BMW spent plenty of time tuning the M5's chassis at the Nuerburgring. Stiff suspension mountings, wide tires mounted on 19-inch (or optional 20-inch) wheels, and Dynamic Damper Control work together for high levels of grip and handling. The suspension dampers and steering can each be switched between "Comfort," "Sport," and "Sport Plus" modes. Six-piston brake calipers grab large discs that measure 15.7 inches in diameter at the front and 15.6 inches rear.
BMW says the new M5 sets new benchmarks for lateral grip and handling, and implies the car can be taken from road to track with only minimal preparation. The doors, hood, and front fenders are all made of aluminum, keeping curb weight to 4279 pounds.
Drive it Your Way
The car is nothing if not configurable. There are three settings each for the engine response, Servotronic steering assist, transmission shift speed, stability-control intervention, and the Dynamic Damper Control -- add them all together, and 243 different vehicle configurations are possible. To keep things simple, BMW has added two M Drive buttons to the steering wheel, allowing the driver to program two presets: M1 could be for twisty mountain roads, while M2 might be a full-bore track configuration. There’s also a special Low Speed Assistance transmission program, which alters throttle response and shifts to make stop-and-go traffic more manageable.
No matter what configuration the driver prefers, the M5 always defaults to its most luxurious, fuel-efficient mode when the engine is started. What a pity.