Under the bonnet lurks a 4.0-litre twin-turbo V8 petrol engine that is capable of dispatching a mighty 592bhp and 590lb ft of shove. Being an Audi quattro, this goes to all four wheels through an eight-speed automatic gearbox. The results are rather punchy: 0-62mph in 3.6 seconds, 0-124mph in 12 seconds and an electronically limited top speed of 155mph. If that's a bit puny for your tastes, there's an option to have the limit increased to 174mph, or have Audi whip off the restrictor altogether, so it'll top out at 189mph. For all that, though, a BMW M5 or Mercedes-AMG E63 S feels quicker and proves to be against the stopwatch. Expect about 21.8mpg on a mix of roads from a well-driven RS6.