Audi’s Predictive Adaptive Suspension: How It Works on the 2021 S8 Flagship

The fourth generation of the German manufacturer’s flagship luxury sedan is inspired by the Audi Prologue concept and was first revealed in 2019.

For the new model year, both the European-spec Audi S8 and the U.S. version get a 4.0-liter twin-turbo V8 that delivers 563 hp (420 kW; 571 PS). It is aided by a 48-volt mild-hybrid electric system capable of energy recuperation using regenerative braking.

Among the many available high-tech innovations Audi is offering, the revolutionary Predictive Adaptive Suspension (PAS) comes standard on the S8. This fully active, electromechanically operated system can increase or reduce pressure on each individual wheel to actively control the position of the car in every driving situation.

Fitted to each wheel, we find an electric motor integrated into the 48-volt electric system, with the four motors controlled by an electronic chassis platform (ECP). This is the brain of the PAS and delivers electrical signals to each electromechanical actuator attached to the electric motors every five milliseconds.

A belt drive with a compact gear layout increases the torque of each motor to 1,100 Nm (811 lb-ft) and transfers it to a steel rotary tube, which is merged to a pre-tensioned titanium roll bar. This bar is more than 400 mm (16 inches) long, roughly 22 mm (0.9 inches) thick, and, regardless of its high strength, can be bent for more than 20 degrees.

The resulting force is transferred from one end of the roll bar to the suspension using a lever and a coupling rod. It's then exerted at the front axle on the pneumatic strut of the adaptive air suspension and on the transverse link of the rear axle.

This results in the ability to lower or lift the S8 up to 85 mm (3.3 inches) from its default position within five-tenths of a second. Thanks to this system, the range of ride characteristics is greatly expanded, resulting in a flexible suspension that can be tailored to the driver’s style.

The dynamic mode makes the car worthy of the S badge, transforming the large sedan into an agile sports car. Body roll angles are significantly reduced, and the car is said to turn into the tightest corners firmly and responsively, without a trace of oversteer.

If the comfort mode is selected, the suspension system completely changes its characteristics, offering a smooth ride on all road surfaces.

Another nice feature that takes full advantage of this innovative system is the ability to lower the S8 by as much as 50 mm (2.0 inches) with a simple touch of the door handle, which makes getting into the car even easier and a lot more comfortable.

The 2021 Audi S8 does not bring many new features compared to the previous model year when it was completely reworked. The only notable changes are 21-inch wheels and heated armrests for the front-seat passengers included in the standard equipment. Prices for the North American version start from $130,900 with the Predictive Adaptive Suspension included.