Category: Exotic Sports 
Price Range: £76,090 to £76,090
Looks better than the estate, ballistic performance, phenomenal V10 engine.
Not as engaging to drive as an M5, thirst hampers range.
Audi comes close to making a four-door Lamborghini.
It would be all too easy to make plenty of assumptions of the saloon, even before it's turned a wheel in anger.
We expected nothing less than the same explosive performance from the 572bhp biturbo 5.0 V10 that we found in the Avant version, but since the saloon ditches the rear greenhouse, weight (which we'll come back to later) drops by 40kg, making it quicker than ever before.
This, in turn, shaves a tenth off the 0-62mph time, which is now an incredible 4.5 seconds. Even more impressive is the fact that the acceleration continues to feel relentless, whatever the speed. The saloon actually feels subjectively quicker than the estate, too. It's all so easy to achieve, thanks to the excellent six-speed automatic: select D, pin the throttle and hold on tight.
Keep it pinned for say, 14.5 seconds - the time the average city car takes to crawl to 60mph - and the big Audi is already nudging 125. Keep on going and in what feels like a ridiculously brief moment you'll be gently bouncing off the 155mph limiter (if you haven't paid the extra to get it shifted to 175mph, that is).
Now addressing that weight loss we referred to earlier, the numbers officially say that 40kg has been taken off, but a particularly cagey engineer said it was actually well over 50kg. We already know the performance impact, but the important point to consider is that Audi had to completely retune the RS's suspension to suit the 'lighter' 1,985kg.
Additional tweaking also means that Audi has rid the RS6 of some of its criticised wooden ride quality, even on 20-inch wheels, and the drive itself is also less inert. Now we're not saying the RS6 has suddenly been transformed into a playful M5-basher that likes nothing more than powersliding out of roundabouts, but the RS6 is certainly more agile, thanks to the suspension's added give and suppleness.
Even more impressive, on the limited roads we drove, there even seemed less of a nasty habit to push into understeer coming into a bends too quickly.
