Electromechanical power steering.

Standard power steering systems work with a hydraulic pump that constantly uses engine performance. The electromechanical power steering is only active when you need it: directly during steering manoeuvres.

With this BMW EfficientDynamics technology, the steering is supported by an electric instead of a hydraulic motor. Whereas conventional hydraulic systems permanently require engine power and therefore fuel, the electromechanical power steering system only works the moment when the steering wheel is turned. If you are driving on a straight road and are holding the steering wheel steady at one angle when cornering, the electric motor is inactive and is not using up energy.