An electronic control unit saves the speed at which you are travelling at the moment you activate the system, and holds it constant by continually comparing this saved speed with the actual vehicle velocity. Variations are corrected by adjusting engine power output. This allows you to maintain speeds between approx. 30 km/h and 210 km/h without the need for corrective measures. The advantages are the driver is less distracted and can concentrate fully on the traffic. It also gives him the possibility of relaxing on long stretches and taking his foot off the accelerator.
Depending on the model of your BMW, the system is operated by an easy-to-use lever mounted on the steering column, or by buttons on the multifunction steering wheel. To deactivate cruise control, simply touch the brakes or press the I/O button. Pressing the ‘Resume’ button (resume speed) will automatically reinstate the previously saved speed.