The Dynamic Chassis
In the new A4 sedan and Avant, dynamics and comfort, easy handling and active safety are at the very highest level. Agility and ride comfort are equally impressive. This road behavior is the result of extensive modifications in the area of elastokinematics as well as to the spring and shock absorber settings.
The predecessor's tried-and-test basic geometry has been adopted at both front and rear: four-link front suspension and the highly complex self-tracking trapezoidal-link rear suspension. Both consist primarily of light-alloy components resulting in a low unsprung mass.
On the four-link front suspension layout, each wheel is located by four aluminum control arms. Large-volume rubber components are used as the damper mounts on the new suspension design. This helps to effectively isolate the shock absorbers acoustically. Several mounts as well as the considerably stiffer track rods on the front suspension have been adopted from the high-performance S4. The mounts for the control arm originate from the new Audi A6.
Together with the new shock absorber settings, the suspension results in a particularly sensitive response to steering movements and even more precise feedback from the road. In other words, extremely dynamic behavior which is isolated almost completely from front-wheel-drive influences.
The trapezoidal-link rear suspension makes for top-quality ride comfort on all models, coupled with dynamic behavior that will amaze the driver of many a competing model.
The trapezoidal link is made from hollow-section aluminium. This torsionally and flexurally rigid control arm absorbs a large portion of the forces acting on the wheel. Together with the track rod located behind it, it thus determines the elastokinematic behavior of the axle.
This design is notable for its low weight as well as its outstanding space efficiency. The compact design permits a low load-area floor in all versions, coupled with a generous load-area width.
The trapezoidal links and wheel carriers on the new A4 generation now also originate from the S4, a car whose suspension has demonstrated its all-round superiority in numerous individual and comparative tests conducted by the trade press. However, several mounts and the shock absorbers, which are considerably larger than on the previous model, have been adopted again from the A6.
Thanks to the precision work that has gone into modifying the rear suspension setup, the dynamic qualities of this basic structure are demonstrated even more effectively. This all adds up to agility and excellent directional stability, outstanding straight-line running and a high level of comfort without any disturbing movements of the body. The S4 has a sport suspension including stiffer shocks and springs, stronger stabilizer bars in the front and rear, and a ride height lowered by 30 mm compared to the Audi A4. The aluminum-intensive design yields low unsprung mass, which nets a sophisticated maximum ride comfort for driver and passengers, while still providing sports car like handling ability.
All versions of the Audi A4/S4 have disc brakes at the front and rear; the front discs are ventilated. Their dimensions have been adapted to the increased performance potential of the new generation of engines. Excellent controllability, spontaneous response and above all considerably reduced braking distances are the result.
The all-new Audi A4/S4 sedan and Avant come standard with hydraulic rack-andpinion steering featuring speed-dependent power assistance, Servotronic®. The development goal here was to provide the highest conceivable standard of sporty steering precision and improved steering comfort.
The refined Servotronic system enables the driver to maneuver into parking spaces with a minimum of steering effort and maximum accuracy, and also provides a clear response from the road at higher speeds. The system also offers a high level of sensitivity around the straight-ahead position and even more comfortable initial response behavior.
All-new Audi A4/S4 models come with the latest Electronic Stabilization Program, ESP®. This system comprises ABS brakes with Electronic Brake-pressure Distribution (EBD) and hydraulic brake assist which automatically increases brake power when the driver applies the brakes in an emergency. The traction control system (ASR) interacts with the electronic differential lock (EDL) to provide efficient yaw control as the foundation for enhanced ESP safety.
The system has been developed to an even higher standard in terms of both electronics and hydraulics. New pressure control ensures even more precise intervention of the ESP stability functions in accordance with the given situation, particularly when the car is understeering. In the event of excessive understeer, all four wheels apply brake pressure if necessary so that the vehicle can be returned to its original course.
Yet another new feature is the brake disc wiping function integrated into ESP. This new function helps to keep the brake discs largely dry on wet roads even when the driver does not apply the brakes for a relatively long time. To provide this effect, the brake linings are pressed against the discs under low hydraulic pressure at regular intervals, ensuring even more spontaneous brake response under wet conditions, too. This process goes unnoticed by the driver.
The new Audi A4 remains faithful to the manufacturer's best tradition of safety. After all, its predecessor was one of the very best in its class in this respect. A rigid body structure and meticulously calculated deformation properties, in conjunction with ultramodern restraint systems - such as the new two-stage front airbags - and outstanding technical concepts such as the Sideguard™ head-level airbag system, created an outstanding level of occupant safety.
In the event of a collision, the car's occupants are effectively protected by the robust structure of the body with predefined deformation and a highly stable passenger cell. The structure also has been improved regarding side crash impact. And in conjunction with seat belt tensioners and belt-force limiters, the full-size front airbags, front side airbags and the Sideguard head airbag system offer the driver and passengers a high level of protection.
The two full-size front airbags are activated in two stages, depending on the severity of the accident. Active front head restraints fitted as standard help to protect the occupants against whiplash injuries in a collision from behind.
Active safety benefits from the latest-generation ESP complete with hydraulic brake assist, anti-lock brake system (ABS), electronic brake-pressure distribution EBD, the traction control system ASR and the electronic differential lock EDL.
A new addition to the list of standard safety equipment is active head restraints on the front seats, which increase protection in a rear impact most effectively. A seat belt reminder system is also part of the standard specification on all new Audi A4 models.
In addition to the large-area front airbags, the occupants are protected by several side airbag systems. In the event of a side impact, remote sensors transmit signals which are compared with those from the sensor in the central airbag control unit.
An extensive system of crash sensors ensures that the airbags are ignited at exactly the right moment. In addition to the upfront sensors, the triggering system comprises several remote satellite sensors at the sides.
All Audi A4/S4 models have provisions for mounting Isofix (LATCH) child seats on the outer positions of the rear seat.
Available as an option is Audi's tire pressure monitoring system. The system monitors the tire pressure and temperature of each individual wheel. In the event of a loss of pressure, it informs the driver optically and acoustically via the display in the instrument cluster.
The system also is able to take minor changes in temperature and pressure caused, for instance, by intense sunshine, hot air coming from the engine or unusual weight distribution of the car into account, thus avoiding a false alarm.
The new Audi A4/S4 is positioned in the midsize luxury segment. It stands out for a range of standard equipment with quality and comfort attributes that would not be out of place in the premium class.
There is a choice more than 10 body colors for the new Audi A4. The color spectrum ranges from particularly sporty shades such as Silver, metallic to Brilliant Red, and also includes the elegant colors in the range such as Liquid Blue, metallic and Dakar Beige, metallic.
As many as three alloy wheels (16- and 17-inch) are available from the launch date, giving drivers a further means of enhancing the characteristic appearance of their new Audi A4.
On the S4, the vehicle is available with a five-spoke 18-inch wheel with high performance tires to ensure an uncompromisingly sporty character in more ways other than just visually.
The interior also satisfies virtually every design requirement. Aluminum finish silver inlays for the center console or, Walnut brown and vavona wood inlays are available.
The optional Audi Navigation Plus system, which uses a DVD drive, helps the driver find the fastest route from A to B. Its operating principle follows the same clear logic as the Audi MMI, familiar from the A8 and A6.
The 6.5-inch color display shows the map and the visual route description, while the driver information system translates the corresponding directions into pictograms and adds information on directions, distances and arrival time.
The A4/S4 standard audio systems offer the ideal combination of convenience and equipment options for every customer:
- Second generation of the Audi Symphony radio
The optional BOSE® sound system with AudioPilot noise compensation additionally provides a concert hall atmosphere in the A4.
The Audi range of unique options also offers perfect solutions for when the sun goes down: the best examples are the xenon plus headlights with outstanding dipped and main xenon beams and automatic-dynamic headlight range control. They illuminate the area in front of the car evenly and intensively.
Even better visibility on the road is ensured by adaptive light including xenon plus. Featuring swivel headlight units, this dynamic cornering light system activates effectively from a speed of about 7 mph and illuminates twists and turns in the road far more than a tradition lighting system. Daytime running lights, which can also be deactivated manually if required, complete the lighting package.
All Audi vehicles sold in North America, including the new Audi A4, come with the Audi Advantage, an industry-leading combination of warranties and protection. This top-rated package includes:
• Four-year/50,000-mile no-charge scheduled maintenance
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