Audi says it will drastically lower the costs of building its aluminum A8 luxury flagship by adapting new production processes learned on the A2.
Series production of the new A8 begins this summer. Sales start soon after September's Paris auto show.
Audi's innovative aluminum spaceframe technology was introduced eight years ago on the current A8. But the production process is mainly by hand and therefore costly. Automation in the body shop is just 25 percent.
A new, more automated process is used on the compact A2 model introduced in 2000. Assembly of the A2's aluminum body is 80 percent automated, using 260 robots.
'We have learned from that process and saved a lot on production costs for the body-in-white,' said Wolfgang Ruch, head of Audi's Aluminum Center in Neckarsulm, Germany.
Klaus Koglin, head of production methods in the Neckarsulm plant, said 'savings of about 50 percent were realized' on the A2, compared with the current A8.
Today, Ruch said Audi can build aluminum bodies-in-white almost as efficiently as steel ones.
'Construction of a sophisticated steel-body structure has become more costly, while we saw our cost come down,' he said.
Koglin said the higher cost of aluminum - which is about four times more expensive than steel - is somewhat compensated because less metal is used for the new A8 body-in-white than a steel body. The new A8 body has 267 separate parts, compared with 334 for the current one.
Code-named D3, the new A8 uses more complex multi-functional castings and single-piece extrusions. Its B pillar is a single casting that weighs 3.63kg. On the outgoing model, the B pillar consists of eight parts and weighs 4.25kg, Ruch said.
The A8's aluminum spaceframe weighs just 280kg, which Audi says is 41 percent less than a comparable steel-body structure. But the new spaceframe is about 25kg heavier than on the outgoing model.
'More severe US crash legislation, in particular the 64kph side impact and 80kph rear impact requirements, have forced us to strengthen the structure,' Ruch said.
Total aluminum content of the A8, including body panels and mechanical components, is 546kg.
'That makes our A8 about 400kg lighter than the Volkswagen Phaeton,' one Audi engineer said.
The body-in-white is held together with 2,600 self-piercing rivets and laser welds. An innovative hybrid welding process, combining metal insert gas arc welding with laser welding, is being applied for the first time.
The new production methods will improve the Audi luxury model's profitability. Audi is building only 220 A2s per day, well below installed capacity of 300 units daily.
'But we are profitable in producing the A2 body,' Ruch said.
Installed capacity for the outgoing A8 is 80 units per day. Currently, 65 units are built daily. Capacity for the new A8 is about 120 units daily.
The A8 will be available in standard and long-wheelbase sedan versions when it goes on sale. A station wagon based on the Avantissimo concept shown at last year's Frankfurt show is under consideration.
'That decision has not been made yet, but it could be added without too much difficulty given the new production methods,' Koglin said.
Alcoa supplies A8 castings. Aluminum panels come from Alcan.
The aluminum structure will remain an Audi exclusive within the Volkswagen group.