Audi A8 to embrace carbon-fibre

Audi says its next generation of limousines will abandon their trademark all-aluminium space frame for first time in the A8's history.

Instead, the next-generation BMW 7 Series rival will be made of a mix of aluminium, steel, magnesium and carbon-fibre-reinforced polymers.

The result, the German car-maker claims, is a structure that has a significant increase in torsional rigidity over the old model with the new space-frame chassis rumoured to be up to 24 per cent stiffer than the current car.

Despite the exotic mix of materials, the need for a higher degree of crash protection means weight actually increases over the outgoing car, with Autocar reporting the new A8's body shell will weigh 51kg more than the old all-aluminium structure.

Part of the reason of beefing up the structure is the need to protect vulnerable and highly explosive lithium-ion battery packs.

The next A8 will come with a 48-volt electrical system, and both standard-wheelbase and long-wheelbase versions have been developed for plug-in hybrid powertrains.

As well as using a mixture of materials for the next-gen A8, Audi has also developed a pioneering remote laser welding process to bond aluminium panels.

The new construction technique is claimed to be far more precise and reduce the risk of 'hot cracking' that occurs with other processes.

Using laser beams also reduces CO2 emissions over the old process by around 25 per cent, says Audi.