Even in an age of ultra-rapid yet silent electric performance cars, there’s something surreal about how quiet the S8 is at low speed. Riding on advanced active air suspension, with a camera scanning the road ahead and automatically adjusting the ride height to smooth over bumps, the car glides along with such tranquility that you can scarcely believe there’s a 4.0-litre V8 just in front of you.
It’s helped by the mild-hybrid unit, a belt-driven 48V starter-motor that can harvest up to 8kW of energy during braking and coasting. Combined with a cylinder-on-demand system that can shut down one bank of cylinders under light loads, it makes the S8 incredibly refined and quiet at low speed.
But call upon the full 563bhp and the engine comes alive with a pleasing – if synthetically aided – roar and a slug of power that a heavyweight boxer would be proud of. It feels as capable as its official 0-62mph time of 3.8sec suggests, especially for a large executive car that weighs 2230kg.
Colin Chapman wouldn’t have approved but, through a combination of that brute force and advanced tech, particularly the variable torque distribution of the quattro system and rear-wheel steering, the S8 can deliver handling, performance and engagement that belies its sheer heft.
That said, that weight and power is reflected in an official fuel economy figure of just 24.4mpg, which comes despite the cylinder deactivation and mild-hybrid system. But that low fuel economy is the trade-off for the substantial performance offered by the S8.
Yet despite its super-saloon speed, the S8 might be at its more impressive when you ease off the throttle and switch driving modes from Sport to Comfort. At a reduced gait, it displays all the polish, refinement and comfort that you expect from the flagship version of the A8 line-up.
At lower speeds, the rear-wheel steering aids manoeuvrability while the air suspension contributes to ride quality that remains as excellent in Britain as in Germany. While large bumps can unsettle the big Audi somewhat, it copes with our rougher, tighter roads with aplomb.
Add in a comfortable, classy cabin with the exemplary polish and refinement that you expect from a high-end Audi and the S8 excels as a limousine-like large saloon. And one that, when the occasion demands, is capable of unleashing mighty performance with similar ease.