The future of the Audi R4, a Boxster-sized mid-engined sports car, currently hangs in the balance as Audi and Volkswagen decide whether steel or alloy body construction is the way forward for the all-new model.
The final stamp of approval for the R4 rests with parent company Volkswagen, according to high-ranking Audi insiders in Ingolstadt.
They say production feasibility studies are yet to determine whether a pressed steel or alloy spaceframe chassis is the better option. The e-tron concept car was based, like the R8, around an alloy spaceframe.
Engineers involved in the studies have told Autocar that lines have been drawn between the cheap-to-produce yet relatively heavy monocoque or the more expensive but lightweight aluminium structure.
One source told us: “The reaction to the e-tron concept has been overwhelming.
"We’re weighing up all of the options and possibilities. There’s no real time pressure because we’re not replacing an existing model but establishing a new one.”
Volkswagen’s involvement in the R4 programme stems from its own plans to use the same platform to create an even more affordable mid-engined coupé/roadster along the lines of its BlueSport concept, which was unveiled at the 2009 Detroit motor show.
In a production strategy similar to that of the Volkswagen Polo/Audi A1 and Volkswagen Golf/Audi A3, the two car makers plan to create two distinctly different cars using a common mid-engine/rear-wheel drive structure.
A final green light for the new platform also hinges on a decision from Porsche, which is studying proposals to create a new entry-level model positioned underneath the Boxster and using the same underpinnings.
"Scale is important to a project like this,” an Audi source told Autocar. “But with three different car makers working to a common goal, the chances [of it getting the go-ahead] look good.”
Although the Audi e-tron concept car was revealed with an all-electric driveline, the production version of the R4 is planned to come with the choice of turbocharged 1.4–litre and 1.6-litre four-cylinder petrol engines as well as a 2.0-litre, four-cylinder diesel engine.