Press Release
Body
The Audi A4 allroad quattro's measurements are as follows: 4.72 meters in length (15.49 ft), a wheelbase of 2.81 meters (9.22 ft), 1.84 meters in width (6.04 ft), and 1.50 meters (4.92 ft) in height. When the vehicle is unloaded, its ground clearance is 180 millimeters (7.09 inches), which is 37 millimeters (1.46 inches) more than the Audi A4 Avant. The basic version's frontal area is 2.24 m2 (24.11 ft2) and the drag coefficient is just 0.34 thanks to extensive fine-tuning and a fully clad underbody.
The body integrates a number of high-strength and ultra-high-strength steel panels which - in turn - reduce the car's weight while enhancing its rigidity, vibrational comfort, and impact safety. At the body's heart, however, are the hot-formed steel units - at the center tunnel, B-posts, inner sills, and bulkhead transverse member. These steel units provide exceptional tensile strength, yet comprise just 11 percent of the bodyshell's weight.
High-tech solutions: Assembly
In addition to resistance spot welding, Audi uses a high-quality structural adhesive while assembling the vehicle's body to further bolster the strength of joints. In the doors and near the sills, an additional high-precision technology is used to reduce the vehicle's weight: remote laser welding.
An array of precisely arranged metal sections protects Audi A4 allroad quattro passengers in the event of an accident. Both front airbags acknowledge the precise positions of the driver and front-seat passenger; in conjunction with the adaptive seatbelt tensioners, passengers of all sizes enjoy excellent protection. In addition, there are side airbags in the front and, optionally, in the rear, as well. Last but not least, a head-protection airbag system also stands at the ready.
In the event of a rear-end collision, a standard, integral head-restraint system for front-seat passengers diminishes the risk of whiplash by supporting the upper parts of their bodies. And the seatbelt tensioners ensure that passengers remain safely seated during a severe rear-end collision. An optional ISOFIX child-seat anchor can be integrated in the front passenger seat; an on/off switch for the airbag is also available.
Chassis
The Audi A4 allroad quattro is a close relative of the A4 Avant, and its chassis retains all the advantages which distinguish the A4 model line. The chassis spontaneously adapts when the vehicle enters a curve; it is also superbly stable and nearly neutral at the A4 allroad quattro's impressive cornering limit. The vehicle's width lays the foundation for these remarkable attributes. The car's track is 1,583 mm (62.32 in.) at the front and 1,574 mm (61.97 in.) at the rear - some 20 mm (0.79 in.) wider, respectively, than the A4 Avant.
At a ratio of 16.1 : 1, steering is straightforward. The low-mounted steering gear conveys the driver's input directly to the wheels. Feedback from the road is responsive: traction forces and disruptive forces are practically imperceptible. Exact centering when driving in a straight line facilitates precise steering from the central position. The steering box's power-steering pump conveys just the required amount of oil, conserving some 0.1 liters of fuel per 100 kilometers. The 3.0 TDI and the 2.0 TFSI roll off the assembly line with servotronic, which adjusts its power-steering assistance to the current speed of travel.
Key components of the front suspension are made of lightweight aluminum: a support for the engine and axle, firmly bolted to the front end to boost rigidity; a mounting bracket connecting the upper trailing arm with the body; a pivot bearing; and five trailing arms per wheel. A tubular anti-roll bar also cuts down on weight. A five-link suspension can handle longitudinal and lateral forces separately. Their bearings are rigid when crosswise, fostering sporty precision; on the other hand, the bearings are remarkably pliable when lengthwise.
The design of the rear axle on the A4 allroad quattro is based on Audi's principle of the self-tracking trapezoidal link, which unites compact construction with top-notch comfort and drivability. A steel subframe connected to the body via hydraulic bearings constitutes the ultrastrong backbone. The trapezoidal link, the wheel carriers, the overhead control arms, and the tie rods are made of aluminum; the anti-roll bar is a hollow tube. The springs are supported directly by the wheel carriers, and are housed separately from the shock absorbers to facilitate ideal performance.
The body is higher than that of the Audi A4 Avant by 37 millimeters (1.46 inches) thanks to correspondingly modified shock absorbers. The Audi A4 allroad quattro standard, 17-inch lightweight alloy wheels in 7-arm V design are fitted with 225/55 tires. 17-inch winter wheels are also optionally available. Audi also offers 18-inch wheels in 5-arm and 10-spoke designs, fitted with 245/45 tires. A tire-pressure monitoring display for all wheels is standard.
Strong stopper: The wheel brakes
Like every Audi, the A4 allroad quattro boasts powerful brakes. The brake disks have a diameter of 314 millimeters (12.36 inches) at the front (320 millimeters (12.60 inches) for the 3.0 TDI) and 300 millimeters (11.81 inches) at the rear. The high-performance brake pads generate a high coefficient of friction and are practically impervious to brake fade. The ventilated front disks have been designed to maximize heat dissipation. In lieu of conventional cooling ducts, hundreds of tiny metal cubes connect the two disk halves - thus allowing a large volume of air to escape. The wheel brakes are very low in weight. The 3.0 TDI has floating calipers at the front; their composite construction consists of high-strength nodular cast iron and aluminum.
The electronic stabilization program (ESP) provides precise and unobtrusive assistance. In rough terrain, a cutting-edge standard feature is put into play: Offroad Detection technology automatically identifies the type of driving surface and accordingly adjusts the ESP's control parameters. When the driver depresses the gas pedal, ESP increases propulsive power by tolerating more wheel spin than otherwise. If necessary, it will brake for a long time in the interest of safety.
On paved roads, the optional Audi drive select system further enhances the joys of driving. It is always paired with Audi dynamic steering in the A4 allroad quattro. Consisting of a superposition gear system integrated in the steering column, Audi drive select varies the steering ratio in a continuously variable manner by nearly 100 percent. It functions directly at low speeds and indirectly at high speeds; the power steering adjusts correspondingly.
If the A4 allroad quattro is at the limits of handling - oversteering, understeering, or during braking maneuvers where one side of the car could skid - Audi dynamic steering keeps the car on course via minor split-second corrective actions. It thus eliminates the necessity for extensive ESP intervention, making driving even safer and smoother.
