This according to Car and Driver, which spoke to Stephan Reil, the chief engineer at Quattro GmbH. Reil says Audi works on a teutonically rigid performance formula: an RS model has to have 20 to 25 percent more power than the existing S version. Considering that the existing S8 makes 512 horsepower and the RS7 a solid 553, we're not sure Audi really needs anything more powerful. But by Reil's calculations, the RS8 would need to pack between 630 and 655 hp, which would put it well ahead of rivals like the 550-hp Jaguar XJR, the 540-hp BMW Alpina B7, the 523-hp Maserati Quattroporte and even the new 577-hp Mercedes-Benz S63 AMG – and in league only with the even more powerful S65 AMG, which in its outgoing form produced 630 hp.
The question then comes down to whether there are enough customers lining up for the S65 that Audi would want to poach away from Mercedes. Or perhaps more pertinently, whether it might end up just taking customers from the new Bentley Flying Spur, which is already offering 616 horsepower in an even more prestigious, if less performance-focused package. Either way you look at it, Audi is apparently steering clear.
And that may not be the only thing it's passing on, either. While previous reports indicated that Audi could put the Nanuk concept into limited production, this same report suggests the crossover supercar would not be in keeping with the company's latest direction.