September 7, 2004

The Audi A4: Exterior/Body
Source: Audi AG

The Exterior

Unmistakably Audi: the new generation of the A4 and A4 Avant once again exhibit the brand's typical design features. Their sports character is immediately visible at first glance.

The ratio of the large, clearly shaped body surfaces to the flat, equally bold strip formed by the windows is significant. The discreetly rising shoulder line accentuates a powerful, dynamic stature, even when the car is stationary. Clear proportions, the gentle curve of the roof, the striking, visibly flared wheel arches: even its silhouette immediately identifies the new A4 as a genuine Audi. 

The new A4 has grown slightly compared with its predecessor: the saloon is 38 millimetres longer, the Avant 41 millimetres. The front end with its more substantial single-frame grille and new bumpers accounts for 12 millimetres of this additional length, the rear end for 28 or 31 millimetres.

The new design elements, however, are even more eye-catching, especially at the front end: the striking single-frame grille and the newly styled clear-glass headlights with their sweeping bottom edge and inward taper give the new Audi A4 a completely new face.

The larger tubes of the main-beam headlights catch the eye under the clear-glass covers of the light unit. With their visible technology they form the visual focus of the headlights and are bordered to the side by round, orange-coloured indicators. 

The bumpers, which are fully painted in the body colour at both front and rear, are also a new design. Thanks to their greater bulge and the fact that they reach a long way down, they accentuate the new Audi A4's low centre of gravity, seemingly bringing the car closer to the road. 

The front-end styling deliberately echoes design elements of the Audi Nuvolari quattro coupé study, thus emphasizing that this model also belongs to the same family as the other new Audi models - the A8 6.0 quattro, A6 and A3 Sportback: a new Audi generation.

The formal idiom of the Nuvolari quattro can also be found at the rear end where the low-positioned two-piece light units, which also arch a long way inwards, emphasize the horizontal design of the vehicle body. The saloon and Avant both sit squarely on the road, the voluminous bottom section and very flat window area combining to produce sports car proportions.

A clearly crafted horizontal light-refracting edge gives the bumpers additional shape. No less eye-catching at the rear end are the exhaust tailpipes which are now 10 millimetres larger at 80 millimetres - a clear indication of just what the new A4 models' engines are capable of.

The side panel sections under the window area are also a completely new design on both the saloon and Avant. The gently rising arch of the shoulder line begins above the front mudguard and runs along the side of the body as a light-refracting edge. It finally merges with the rear lights where it is continued in their upwardly arching top edge. Proportions of the kind typically found on sports cars are the characteristic feature of the side design: high body panels and a flat window area.

Another sign of the family resemblance that the new A4 has with the Nuvolari quattro study and also the current Audi A6 is the striking but ever-discreet dialogue of concave and convex arches, of curved surfaces facing towards and away from the light. The result is an extremely stimulating interplay of light and shadow, giving the car its own very special appeal from every perspective.
 

The Body

The body of the new Audi A4 is based on a unitary steel structure with integrated aluminum components. The percentage by weight accounted for by plastics and the use of the lightweight materials aluminum and magnesium is considerable.

A further decisive measure with a low vehicle weight in mind is the expansive use of high-strength and very high-strength sheet-metal panels, which make up a total of 45 percent of the bodyshell weight. These special sheet panels are used primarily in the front end of the new A4, where the main priority is to absorb impact energy as effectively as possible in a frontal crash.

As a protective cage, the occupant cell must also make sure that deformations and intrusions are minimized in a crash. Part of this task is performed by three large tailored blanks incorporated into the floor area. The wall thickness of each of these blanks varies. They are joined together by laser weld seams.

The advantage of this special technology is that the generally large-format tailored blanks can be structured in such a way that high wall thicknesses are only used in areas subjected to particularly high loads. The result is a highly rigid structure which weighs less. A total of ten large tailored blank components are installed in the new Audi A4

For the passenger cell, the tailored blanks form a stable, homogeneous bond with the forward and rearward structure via a bifurcated system of support members. Audi's development engineers optimized profiles, wall thicknesses and material grades in extensive crash simulations.

In the rearward structure, the vehicle's longitudinal member - which has to absorb much of the impact energy in a rear-end impact - is made using tailored blanks of varying wall thicknesses and material grades.

The use of tailored blanks at specific points around the doors also helps to save weight. Extruded aluminum sections are incorporated into the doors and sills by way of impact protection.