The running gear on the Phaeton is designed for maximum levels of driving performance, comfort and safety. The basic layout of the running gear consists of a four link front suspension and a trapezoidal link rear suspension. A standard feature – and this is by no means a given in this class – is the four-wheel air suspension coupled to the running gear. The bottom line is that this air suspension plays no small role in creating one of the most comfortable suspension systems in the world. In parallel, a standard 4MOTION all-wheel drive system leads to an exceptionally high level of active safety. An entirely new brake system solidifies this fact in the latest Phaeton.
Four-wheel air suspension
The high level of driving safety on the Phaeton, which goes hand in hand with its superior vehicle dynamics, was achieved while realising extremely good comfort properties. One reason for this, already mentioned, is the standard air suspension system. The goal of running gear developers was to design a spring system that would fulfil the highest standards in terms of both driving comfort and vehicle dynamics. Air spring systems with controlled damping are extremely well suited for this purpose, since they offer numerous advantages compared to conventional steel spring systems.
The levelling system of the air suspension enables a soft, load-independent and therefore comfort-oriented spring layout and intentional lowering of vehicle ride height at high speeds. The results: lower fuel consumption and less tendency to roll.
The physical behaviour of the air suspension makes it possible to automatically adapt the spring rate and vehicle's ride height to the given load, and so the system simultaneously performs the function of a classic level control system. This maintains driving comfort at the same high level in all load states. Moreover, the system reduces load-related changes in vehicle dynamics. Continuously variable damping control improves ride comfort and driving safety significantly.
The air suspension itself consists of these basic elements: a total of four air spring arms at the front and rear axles, an air supply unit, a pressure reservoir, a control module, a total of four level sensors at the front and rear axles, three accelerometers on the vehicle body and four accelerometers on the wheel suspensions.
The core system components are its four air spring modules. Their specially fabricated outer bellows guarantee a very gentle response to every suspension movement. The desired low spring rate is ensured by an additional volume as well as special piston contouring, which has a positive effect on the dynamic behaviour of the air spring. In addition, the damping force at each spring arm is adapted to momentary demand in just milliseconds via an electrically controlled valve integrated in the piston of the hydraulic damper. Data from the wheel accelerometers on the dampers and the total of three body accelerometers are used to compute optimal damping forces for direction and stability. This is an intelligent engineered system that gives the luxury class saloon exceptionally responsive handling, yet makes it extremely comfortable. The air spring system with dynamic damping produces a running gear configuration whose advantages in vehicle dynamics do not sacrifice ride comfort.
The Phaeton can adjust to three different chassis height levels: the Normal level (NL), High level (HL) 25 millimetres above the Normal level, and the Low level (LL) 15 millimetres below the Normal level. This level is automatically controlled as a function of speed to optimise driving properties and fuel consumption (from 140 km/h).
Of course, the driver can also intervene manually in tuning the running gear. There are controls for levelling and damper control behind the gearshift lever on the centre console. These buttons give the driver a choice of two height levels (NL and HL) and four damper characteristics (Comfort, Basic, Sport, Sport2).
4MOTION all-wheel drive
The Phaeton is equipped with all-wheel drive in all versions. The 4MOTION all-wheel drive offers significant advantages primarily in traction and handling compared to the rear wheel drive that is usual in this market segment. In particular, 4MOTION plays out its advantages in critical load alternation effects – nearly independent of control systems such as ESP that is standard in the Phaeton. Power distribution of the 4MOTION drive is fully variable, and power is directed to each four wheels based on slip. This means that propulsive power is always distributed individually, and this makes it possible to maintain optimal traction and cornering force for each wheel.
The Torsen differential plays a key role in power distribution; it reacts to even the slightest of speed deviations. Specifically, the 4MOTION system works as follows: Power is transferred into the Torsen differential along a path over the planetary gears of the automatic transmission and the spur gear stage. Normally, half of the torque is directed to the propshaft and thereby to the rear axle, and half via an intermediate stage to the front axle (power distribution 50:50). The rigidity of the drivetrain is exemplary; this has a positive effect on noise behaviour in start-off and in load alternation.
Notes:
All features, data and prices contained in this press packet apply to models offered in Germany. They may differ in other countries. All information is subject to change and correction.
TDI, TSI, DSG and Twincharger are registered trademarks of Volkswagen AG or other companies of the Volkswagen Group in Germany and other countries.