Having arrived as part of the current fourth-generation A8 range back in 2020, the S8 (which comes in short-wheelbase form only) offers a similar blend of big-hitting turbo-petrol V8 performance, top-level refinement, uncompromising luxury and understated performance styling as that for which so many of its predecessors have been known.
But it offers even more Audi-typical advanced drivetrain and suspension technology as standard, much of which isn’t available on any other A8. Quattro four-wheel drive is there to put the engine’s 563bhp to effective use, of course, but here you get an active ‘sport’ rear differential in addition to the mechanical centre diff of other A8s, while four-wheel ‘dynamic’ steering comes as standard (it’s an option on the rest of the range).
And then there’s the suspension, which is the really clever bit. While other A8s have a simpler adaptive air suspension system, the S8 gets what Audi calls Predictive Active Suspension, which mixes forward-facing cameras with a height-adjustable air suspension set-up that incorporates fast-acting electromechanical actuators at each wheel.
The cameras scan the road, while electro-mechanical actuators constantly vary the car’s ride height and manage its wheel deflections. Each wheel can be separately loaded or relieved depending on the road conditions across five driving modes. In Comfort+, the suspension tilts the body into corners to reduce lateral forces. In Dynamic, body roll is reduced to around half of that of a standard steel sprung suspension, according to Audi.
While the same suspension can be optionally fitted to other A8s bought elsewhere in the world, Audi UK only offers the fully active set-up as standard on the S8.
Under the bonnet, the S8 uses a twin-turbocharged 4.0-litre V8 petrol with mild hybrid assistance. With 563bhp, its power was wound back by 34bhp over the ultimate version of the third-generation S8 – the S8 Plus, which used a less heavily developed version of the same engine. But with up to 1.8bar of turbocharger boost pressure, torque increased by 37lb ft, now peaking at 590lb ft on a band of revs between 2000 and 4500rpm.
Those reserves are sent through an eight-speed torque converter equipped automatic gearbox with a manual shifting Tiptronic function, and Audi’s Quattro four-wheel drive system, together with a ‘sport’ differential that constantly varies the amount of drive sent to each individual rear wheel.
Audi made surprisingly big claims about the S8’s efficiency when it first appeared in 2020. It uses both a cylinder on-demand system that automatically closes down one bank of cylinders on light throttle loads at urban driving speeds, and a new belt-driven 48-volt starter motor that operates in combination with a lithium-ion battery and a recuperation system capable of harvesting up to 8kW of energy during braking and coasting.
