The adaptive restraint system is networked with Audi pre sense. It draws its own information from eight acceleration and pressure sensors at the front of the car, in the C-pillars and in the doors. It manages the interplay between the airbags and the belt force limiters to offer protection to passengers of any size, with smaller persons benefiting in particular.

Sensors on the front seat rails detect how far forward or back the seat is positioned. Because the control unit then estimates the approximate position of the passenger, it can ensure that optimal use is made of the distance over which the upper body is slowed by the belt and the airbag. Audi pre sense reduces this distance by roughly 10 centimetres (3.94 in) because the belts are tensioned before the crash occurs.

If a passenger is sitting close to an airbag – this is typically a smaller person – a portion of the air is quickly expelled via valves after the airbag inflates. In a hard crash or with large occupants who sit farther back, the valves remain closed longer. The variable belt force limiters are also designed to be adaptive. They control belt tension so that the load on the chest remains as low as possible. Bracing structures, energy-absorbing pads and crash-optimized pedals reduces loads on the feet and legs.

In the case of a rear-end collision, which frequently occur at traffic lights, usually with impact speeds between 15 and 50 km/h (9.32 and 31.07 mph), the seatback is accelerated to between 7 and 25 km/h (4.35 and 15.53 mph) within a tenth of a second. The integral head restraint system from Audi acts here to counter the risk of whiplash injuries.

Four side airbags in the backrests of the front seats and the outside rear seats protect the pelvic area and chest of the occupants in side-impact collisions. Stretching from the A-pillar to the C-pillar, the head airbag system opens like a curtain from the roof frame to the door sill.

The new A8 has three-point automatic seatbelts with tension limiters at all five seats. The rear seats are equipped with Isofix fixtures for installing child seats.

For the protection of pedestrians, a special foam between the front bumper and its crossmember makes the impact slightly easier on the knees. If the head should hit the engine hood, the sheet metal can deform over a wide range. The gap between it and the hard components in the engine compartment is large.

The front and rear sensors remain undamaged in the event of a low-speed parking crash because they are integrated into the deformable covering of the bumpers. The radar sensors for the ACC stop & go function and the camera for the night vision assistant are deep inside their cavities.