The new Audi A6 is up to 80 kilograms lighter than the predecessor model. Audi has thus broken the unwritten law that says that cars become heavier with each new model line.

It appeared to be a basic principle in the automotive industry: every new model was heavier than its predecessor. This was because each additional comfort or safety improvement resulted in an increase in vehicle weight. More weight makes it necessary to increase engine output in order to ensure the same driving characteristics. This in turn creates the need for a stronger gearbox and brakes as well as a larger fuel tank – thus increasing the car’s weight even more.

Audi’s response to this development was to take the first radical step in the other direction. Thanks to an Audi ultra-lightweight body that is significantly lighter in weight than the conventional structure, it was possible to completely reverse the weight gain. Just as each additional gram of weight is multiplied due to the measures that then have to be taken, each gram less has the opposite effect: smaller engines and tanks, brakes and gearboxes.

The result is lighter vehicles with the identical driving characteristics and a crucial advantage – lower fuel consumption.

Lightweight construction is often mentioned in the same breath as aluminium. However, the use of light alloys is only one way of saving weight. Audi is already using innovative combinations of materials in many areas.

The Audi Space Frame is one of the most important innovations in the field of lightweight construction: the aluminium body created by Audi is recognised today as one of the milestones on the way to developing significantly lighter vehicles. However in addition to the aluminium design, Audi also develops multi-material concepts, some of which are lighter or stronger. As well as aluminium, Audi focuses on carbon fibre-reinforced polymers, state-of-the-art steel alloys and magnesium.

The main requirement put on our lightweight construction engineers is specialist know-how in the field of joining techniques. Thin aluminium panels can easily become damaged during welding. Some materials cannot be welded together at all – they have to be riveted, joined with adhesive or with self-cutting threaded screws.

Audi has deliberately been breaking new ground in this area for many years and has built up specialised technical knowledge that can be used in production. Thanks to this know-how, it is possible to combine together virtually all the materials relevant to the vehicle construction industry. This is a distinct advantage, as this is the only way that it is possible to use just the right material in every part of the car – with no compromises.

For a long time, the use of plastics in premium vehicles was frowned upon. But what used to be referred to with disdain is now a high-quality, high-tech material that opens up completely new possibilities for lightweight automotive construction.

Carbon fibre-reinforced polymers (CFRPs) are extremely interesting; they can be processed in a variety of ways and can be moulded into virtually any form. In addition to the variety of processing options, the weight is also a key advantage: CFRPs are approximately 60 percent lighter than steel.

Fibreglass reinforced plastics (FGRPs) are of particular interest for lightweight construction when used in combination with other materials. FGRPs are also extremely strong even when used alone, for example in the form of seat pans with undercarriage made solely from FGRP – they are 31.5 kilograms lighter than the standard production seats.

Innovative materials are already used in every new Audi.