adaptive cruise control

Clear benefits are delivered primarily in terms of driving dynamics. The adaptive cruise control features enables a desired speed of between 30 and 200 km/h to be preset, and overcomes the disadvantages of earlier systems, which often operated at a time lag. With adaptive cruise control the degree of dynamism when accelerating is determined by the driver himself. Four programmes are available to choose from: Distance 1 (sporty); Distance 2 or Distance 3 (standard); Distance 4 (comfortable).

If the Distance 1 programme is selected, the distance to the vehicle in front is set at its shortest (though within legal limits and in accordance with sensible driving practice). Why this programme is called "sporty" is demonstrated most clearly when the vehicle driving in front on the motorway turns off onto an exit road. The Audi A8 utilises the newly vacant space to return to its preset cruising speed, even shifting the tiptronic transmission system down by as much as two gears to do so.

The Distance 2 and Distance 3 programmes are ideal for relaxed and assured cruising in free-flowing nose-to-tail traffic. The Distance 4 programme is ideally suited to comfortable cruising on well-maintained country roads or when pulling a trailer.

If the adaptive cruise control detects a vehicle in front moving more slowly, or indicates a jam is building up, the system of course ensures that the stipulated distance is maintained. That is to say, it initiates moderate deceleration by pulling back the throttle. If that is not sufficient, the brakes are automatically applied - to around 25 percent of the maximum possible vehicle deceleration. If the distance is still too short, the adaptive cruise control delivers a prompt (gong) to the driver in good time for him to take over control of the vehicle. This warns the driver promptly of any unexpected situation arising.

The adaptive cruise control does not respond to stationary obstacles or oncoming traffic. It must not be used on winding roads or in adverse weather conditions such as fog, ice or heavy rain.