We’ll start with the negatives. If the RS6’s immensely powerful 4.0-litre V8 disappoints in any aspect, it’s in the way it sounds. There’s a richness and an aggression to its deep, growling timbre that’s eminently appealing when you can hear it, but compared with the more expressive V8 of the Mercedes-AMG E63 and, to a lesser extent, the BMW M5’s, the Audi’s engine just sounds a bit restrained.
Even with the optional RS sports exhaust fitted, the way in which its soundtrack swells into the cabin is akin to listening to a favourite music album from another room. In this sort of car, you’d just prefer to be able to hear it in more detail and at apparently closer range.
The other slight sticking point is that we averaged just 19.5mpg during our time with the car – a figure that dropped to 9.8mpg during performance testing. Allowing for the fact that this engine develops 591bhp and the car weighed 2.2 tonnes on our scales, fairly extreme fuel consumption isn’t exactly a surprise. However, it does erode the car’s everyday ownership appeal a bit and reveals that Audi’s economy-boosting measures will have a rather limited effect should you choose to stretch the car’s legs.