Audi S8 review

To put this into perspective, the newly facelifted BMW M750i xDrive’s twin-turbocharged 4.4-litre V8 petrol engine delivers 523bhp and 553lb ft, while the Mercedes-Benz S63’s twin-turbocharged 4.0-litre V8 powerplant serves up 603bhp and 664lb ft.

The stronger reserves are sent through an upgraded eight-speed torque converter equipped automatic gearbox with a manual shifting Tiptronic function and Audi’s quattro four-wheel drive system with a so-called sport differential that constantly varies the amount of drive sent to each individual rear wheel. Depending on the conditions, up to 70 per cent of drive can be delivered to the front wheels. Alternatively, 85 per cent can also be apportioned to the rear wheels.

Audi makes big claims about the new S8’s efficiency. It boasts 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 0.47kWh lithium-ion battery and a recuperation system capable of harvesting up to 8kW of energy during braking and coasting. Together, they are claimed to reduce consumption by almost 0.2mpg.

Yet despite the impressive energy-saving technology, combined cycle fuel economy is reduced from a previous 29.4mpg to 24.8mpg, giving the new S8 an average CO2 rating on the NEDC cycle of 260g/km.   

It’s the suspension, though, that Audi is relying on to allow the new S8 to successfully achieve it dual roles. The new system, known as Predictive Active Suspension, uses a camera to scan the road and electro-mechanical actuators to constantly vary the ride height. 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.

As always, there’s little to tell the fourth-generation S8 apart from its less sporting A8 sibling. Audi has a long history of delivering some of the most sought after understated performance saloons, and it is successfully employed here. At standstill, the new model looks pumped but subtly so and without any obviously contrived design elements. Among the unique touches is a new front bumper housing an S8 specific double louvre grille, wider sills beneath the doors, aluminium-look mirror housings and Audi’s signature S-model quad tailpipe treatment at the rear.

When you open the driver’s door the S8’s active suspension automatically raises the ride height by 50mm to ease entry. As the door is closed, the air springs return to their nominal setting as the body is lowered again. It’s a nice touch that showcases the advanced underpinnings of the new Audi every time it is driven.

Inside, it’s a similar story to the exterior, with subtle updates to the standard Audi A8 interior. Subjectively, there’s precious little room for improvement in what remains one of the best interiors in any car at any price. But with unique carbon fibre and aluminium trims the new S8 manages to provide added appeal.

Expensive looking and agreeably tactile materials combine with crisp and clear digital instruments as well as a standard 10.1-inch touch display for the infotainment functions, a lovely multi-function steering wheel and highly supportive sport seats to provide a truly first class driving environment.

In the right conditions, the big Audi is brutishly potent with earnest step-off qualities and unrelentingly urgent in-gear traits. The brawny engine is the undisputed star of the show, with the sort of sledgehammer performance to propel it from standstill to 62mph it in a scarcely believable 3.9sec.

The slick shifting eight-speed torque converter automatic gearbox and fast acting quattro four-wheel drive system also play an integral part in the explosive accelerative and top shelf cruising ability.  Together with the engine, they form an intoxicating combination that is further enhanced by a convincingly realistic synthesised soundtrack played over the speakers.

Yet, as effective as it is under full load in sport mode, the S8’s engine is also compellingly smooth on more measured throttle inputs in an altogether more relaxed Comfort+ mode. In city driving, it proves wonderfully flexible even in Eco mode, where the cylinder on demand system closes down one bank of cylinders, essentially turning the engine into a four-cylinder unit for brief periods.  

The most remarkable thing about the new S8, however, is the added agility brought by the adoption of Audi’s Predictive Active Suspension and Dynamic All-Wheel Steering system. As well as varying the assistance acting on the steering of the front wheels, it adds a steering function to the rear wheels, which turn in the opposite direction to the front wheels at low speeds and in the same direction at higher speeds.

The upshot is a new found level of communication and response. Despite its generous dimensions, you can place the new S8 with added precision and confidence in any given driving situation. On more challenging roads, there’s a welcome liveliness and neutral character to the big Audi that was always found wanting in its predecessor. With the predictive function to the suspension able to alter the characteristics of the damping up to 18 times per second and an ability to lean into corners in a manner similar to motorcycle, the new S8 is more composed and fluid. The trademark directional stability has also been improved, bringing added stability at higher speeds.

An added advantage of the adoption of rear wheel steer is a reduction in the turning circle at low speeds, a development that facilitates manoeuvring during parking and low speed urban driving.  Primary ride quality is also improved. However, the S8 is still unsettled by larger transverse ruts and ridges. 

Earlier incarnations of the S8 were persuasive ownership propositions. The problem as far as enthusiast drivers were concerned is they all lacked the inherent engagement that sets a truly great car apart from a merely good one. As such, they never really rose to the challenge in a way Audi would have had us believe. Outstanding when charging flat out down an empty autobahn, but somewhat detached on more challenging back roads.