The B7 RS 4 does superbly on the track in all aspects of performance, including acceleration.

The C5 RS 6 does better than the B7 RS 4 on the track in straight line acceleration only.

However, the B7 RS 4 rapes the snot out of the C5 RS 6 on the track in every other aspect of performance and gets better, if still embarrassingly, though certainly not mortifyingly, horrible fuel economy than the C5 RS 6, whose fuel economy is also embarrassingly, though certainly not mortifyingly, horrible.

Quite frankly, the C6 S6 outperforms the C5 RS 6 at the track in all aspects of performance other than acceleration, where the C5 RS 6 marginally outperforms the C6 S6. Other than acceleration (where the C5 RS 6 rapes the snot out of a regular C6 A6), the C5 RS 6 barely outperforms the regular C6 A6 at the track.

Of course, if you overlook acceleration, you would have to be a gargantuan imbecile to put the C5 A6 and C5 S6 against any version of the C6 A6, especially against the C6 S6 and, most of all, the C6 RS 6 at the track. All of the Audis mentioned in here, again, get embarrassingly, though certainly not mortifyingly, horrible gas mileage when equipped with petroleum engines, though the C6 RS 6's fuel economy will most likely, if not definitely, border on being mortifyingly horrible.

All of the automotive professionals worldwide that test vehicles on a track (including the BMW loving, Audi hating pigs at the UK automotive press as well as the BMW loving, Audi hating pigs at Automobile magazine) have confirmed all of the above, making all of the above official.