Audi A8 D5 gets heavier despite lightweight parts

At the end of 2017, the Audi A8 (D5) will receive a new Audi Space Frame design that contains magnesium. The luxury sedan weighs more despite its innovative lightweight design. What caused it?

The D5 series of the flagship Audi A8 (audimanual) uses a four-material blend body for the first time. Aluminum remains the most commonly used material: 58% of the composition of the innovative Space Frame consists of light metal. The body structure, the so-called roll cage, is made of hot-forged aluminium. The plastic base (CFK) of the rear seat is made of reinforced carbon fiber, while the transverse support in the new A8 is made of magnesium. The A-pillar alone is 28% lighter than its aluminum predecessor. Why is the sedan still heavier despite its lightweight design?

This is due to increased requirements for safety, technology and drive. The hull alone weighs 282 kg, while the predecessor weighed 231 kg. Of course, the improved bodywork should offer more features, such as room for different caliber batteries on electrified models and the guarantee of safety and reliability in the event of an accident. The increased requirements of the driver and passengers must also be met in accordance with higher standards of comfort and reliability. That is why there are more and more sensors and electronics in the basic equipment of the car, and when the content increases, Audi adapts the materials.

Simplified landing and better visibility in all directions

Overall, the new A8 is about 24% more torsional-resistant than its predecessor, which the manufacturer says is critical to precise handling and acoustic comfort. A value that is a compilation of many sub-elements: for example, Audi engineers have developed a new cast aluminum alloy that, after a four-stage heat treatment, is 50% stronger and 15% smaller. The same applies to aluminum sheets, which account for a third of the stability. Thus, each point of the body will contain as much material as is necessary for this purpose. This basic idea also explains why some parts have different cross-sectional thicknesses. Since in some places a material thickness of two millimeters is not required, for example,

“We have improved not only the individual materials, but also the technology of their connection, because it is very important that the different materials are optimally connected,” says Bernd Mlekush, director of the lightweight construction center. For example, the flanges of the front, middle and rear pillars. This is where aluminum and steel meet, with thinner pillars, 16mm larger front doors, and a five-degree better viewing angle.

New Audi A8 retains Q7 platform

The new Audi A8 is based on a revised modular platform (MLB/PL65) that was first used in the new Audi Q7 and later in the A9 Coupé and Q8 Crossover. The new Audi A8 is unlikely to rely on Porsche's sportier MSB rear-wheel drive platform. The new Porsche Panamera is built on this platform, as is the Bentley Continental.

The new platform also enables the integration of autonomous driving as well as infotainment and driving modes based on the MIB2+ system. This allows the new MMI version to be integrated with a much larger TFT monitor with gesture and voice control, and the passenger next to the driver also has their own screen.

German precision in the Audi A8

The latest images of the prototype reveal much more than the design of the new Audi A8, which is entirely the work of Marc Lichte's pen and very close to the Prologue studios. The length and wheelbase appear to have changed only slightly. The radiator grille will become larger in the future. The interior has retained the shape of a coupe, and the rear has become narrower. The proportions are quite harmonious. The sides of the new A8 are adorned with the so-called Tornadolini, the sharp edge of the bodywork (see photo). “Fortunately, we were able to form such a thin aluminum edge. Otherwise, the designers would have had much more work to do,” Mlekus, director of the Lightweight Construction Center, expressed satisfaction.

Audi attaches great importance to the fact that the new A8 will have autonomous driving and independently increase the speed to 130 km/h.

Trusting conventional V6, V8 and W12 units is a matter of prestige for Audi. On-board network 48V allows the use of an electric compressor. The new 4.0-liter V8 engine from the Porsche Panamera is expected to generate around 470 hp. As for diesel units, the power range extends from 320 hp. 3.0 TDI and over 400 hp on 4.2 TDI. Accordingly, the units are aggregated with an eight-speed automatic transmission. A plug-in hybrid version is considered mandatory. Even the quattro drive is certainly acceptable for almost all engines, as well as for the long version of the sporty Audi S8, which can reach 560 hp. All-wheel drive and an eight-speed automatic transmission are an integral part of the powertrain.

Manuals and instructions for the overhaul of the car Audi A8 D2: http://www.audimanual.ru/en/A8/D2