Background
The Audi S8 has long occupied a special niche in the super saloon firmament. On paper, it's hopelessly outgunned by rivals with bigger engines, but if you look beyond the Top Trumps figures, it's a car that just oozes cool. Every version of the S8 has always had something exotic about it, starting with the original 4.2-litre 'D2' model of 1997 made famous as the getaway car in the Robert de Niro film 'Ronin'. A 5.0-litre V10 MK2 'D3' version followed in 2006, followed by the 4.0-litre V8 'D4' variant launched in 2012.
This fourth generation 'D5' design was launched in 2019 and remains very much the 'Ronin' car, the ultimate low-profile, high-drama getaway choice. It retains a more responsible version of its predecessor's potent twin-turbocharged 4.0-litre V8 beneath the bonnet, a powerplant that makes this Audi a very effective long distance express indeed. This is still the genuine article. Even more so in this facelifted form.
Driving Experience
The 571PS 4.0-litre twin-turbocharged V8 under the bonnet of this fourth generation S8 might be 34PS down on the output generated by the final 'S8 plus' version of its 'D4'-series pre-2017-era predecessor, but pulling power has increased in this generation to a thumping 800Nm, so it's very definitely quicker in the real world. Torque is transmitted to tarmac via an upgraded 8-speed tiptronic auto gearbox, predictive active suspension, dynamic-all-wheel steering and quattro 4WD supplemented by a rear sport differential which constantly varies the amount of drive sent to each individual rear wheel. The quattro system's variable too. Depending on the conditions, up to 70% of torque can be directed to the front wheels - or alternatively, up to 85% of power can be directed rearwards. And of course this S8 is fast; 62mph from rest takes just 3.8s.
Perhaps the key change made with this 'D5'-series model though is the addition of its 'Predictive Active Suspension' system, which uses a camera to scan the road ahead as you drive, along with electro-mechanical actuators that constantly vary the ride height to suit the tarmac ahead, separately loading or relieving each wheel based on road conditions to an extent that depends on the 'drive select' driving mode you've chosen. Choose 'Comfort+' for instance and the suspension tilts the body into the turns to reduce lateral load. Choose 'Dynamic' and body roll is cut by around half what you'd get with standard sprung suspension.
Design and Build
Slightly bolder interior and exterior design elements are intended to finely hone the character of the improved version of this fourth generation S8. This model's based on the shorter wheelbase body shape and as with more ordinary A8s, there's a larger Singleframe front grille, a restyled front bumper, smarter side skirts and a sleeker rear valance at the back. The LED headlamps are also restyled - and feature Audi's latest Digital Matrix LED tech where each light unit contains 1.3 million micro mirrors. The smarter OLED rear lights meanwhile, have a built-in proximity sensor which activates them if a following vehicle gets too close. As before, details in the front bumper, side sills and the exterior mirror housings as well as the two S-specific twin exhaust tailpipes subtly convey the car's standing in the model series.
The cabin's distinguished by an upper inlay exclusive to the S8 made of Carbon Vector with a special 3D depth effect. Directly below that is an inlay of dark, brushed matt aluminium. The standard sport seats are trimmed in either Valcona or Unikat premium leather. As before, there's a 12.3-inch Digital Cockpit instrument screen, plus two centre monitors, a 10.1-inch one for the media functions and a lower 8.6-inch unit just for the climate controls. All three screens now run on updated software. The instrument screen features S-specific red graphics and a special S-performance layout where the focus is the rev counter, displayed as a square graph. Out back, as you'd expect, there's opulent room for a couple of adults in the leather-stitched rear compartment. And of course you get a big 505-litre boot.
Market and Model
The asking price of this S8 might seem high - starting from around £100,000 at the time of this test in Autumn 2022: it is high - but that's significantly less than you'll pay for comparable models in this category like the identically-powerful BMW M760e xDrive, but that Munich model is a Plug-in Hybrid - as are the Mercedes-AMG S63e and S73e models. An arguably closer match is the more conventional 530PS V8 powerplant of the Maserati Quattroporte Trofeo, but that costs around £130,000. You might also consider BMW's M6 Competition Gran Coupe and the Porsche Panamera Turbo, but those are also much pricier too.
Despite that, this flagship A8 model is opulently equipped, particularly if you pay more for 'Black Edition' or 'Vorsprung'-equipped versions, which respectively cost £3,000 or £15,000 more. One particular highlight lies with the standard sport seats, which feature wide ranging power adjustment, pneumatically adjustable side bolsters and separate three-stage heating for each seat. In addition to this, at the top of the range, ventilation and massage functions are available. Options with standard and 'Black Edition' trim include a Bang & Olusen 3D Sound System and red brake calipers.
Cost of Ownership
Audi makes much of this MK4 model's mild hybrid engine tech. This works using a belt-driven 48-volt starter motor which operates in conjunction with a 0.47kWh lithium-ion battery and a recuperation system capable of harvesting up to 8kW of energy during coasting and braking. There's also cylinder deactivation which at light-to-medium throttle loads will see the car operating with only four of its eight cylinders. But in the small print, you discover that the effect of all of this is to reduce consumption by just 0.2mpg. Which isn't nearly enough to make up for this 'D5'-series model's higher running costs; its combined cycle fuel economy figure is 24.6mpg and the CO2 return is a smoky 260g/km.
In short, the S8 might be many things but it's certainly not an inexpensive car to run. And there's more less welcome news that probably won't bother potential well-heeled buyers. Insurance is still a top of the shop Group 50. And depreciation at around 34 per cent after three years is not the bulletproof residual figure many come to take for granted from Audi. It's no wonder that the S8 is a car that makes a very canny used buy two or three years down the road. One area where the S8 might save you a few bob is, rather surprisingly, tyres. Owners have reported that due to the modest weight, load spread via the four-wheel drive system and smart traction management, it's possible to see over 20,000 miles from a set of rubber.