It is available as an optional extra in connection with Porsche Doppelkupplung (PDK). The system regulates the speed of your 911 automatically, depending on the distance to the car in front, by the radar sensor monitoring the area in front of your car. If you have set a certain speed and you are getting closer to a car in front of you that is travelling slower, then your system will reduce your speed by taking away some acceleration and careful braking, until the preset distance has been achieved. Your 911 now keeps that distance from the car travelling in front of you. If it applies the brakes, then the adaptive cruise control also reduces the speed, until the vehicle reaches a standstill.
The system also prepares for braking, if the distance to the car in front is decreasing. It will warn you with sound and visual signals if it recognises the situation as a potential accident risk. In addition, the brake is briefly engaged. If the driver carries out emergency braking, then the started brake action is reinforced within certain system limits by the brake power support.