Four wheel steering
New to the BMW 7-series is Integrated Active Steer, which uses an electric motor to turn the rear wheels by up to three degrees. At low speeds they turn in the opposite direction to the fronts ones, to reduce the turning circle by up to 70cm. At higher speeds they turn in the same direction, reducing the yaw and improving the vehicle's stability.
The concept's nothing new - the Mazda 626 and Honda Prelude had 4WS in the 1980s - but the technology's been dramatically improved by today's more powerful electronics. They can reduce the number of mechanical linkages needed and provide artificially created feel to compensate for the unnatural feedback created by the movement of the rear wheels.
All wheel drive
The 7-series will get four-wheel-drive for the first time, helping it take on the A8 quattro and increasingly popular S-class 4Matic. It will get BMW's torque-vectoring system, which the company has said will be fitted to all four-wheel-drive models. Only two cars on sale, both from Japan, have four-wheel steering and four-wheel drive: the Honda Legend and the new Nissan GT-R.
One big mechanical change is the replacement of MacPherson strut front suspension with an all-new double wishbone design that, like the multi-link arrangement at the rear, is made almost entirely from aluminium. The change has been made, BMW says, to provide improved camber control for better front-end grip.
All models come with Dynamic Damping Control as standard. This new system represents a major advance on existing arrangements, as it can alter the compression and rebound characteristics independently of each other. In addition, the 740Li and 750Li get air springs at the rear.
In line with the promise of increased driveability, the new 7-series comes with BMW's new Dynamic Driving Control. This system can alter the damping, steering and throttle mapping in four levels: Comfort, Normal, Sport and Sport Plus.