Audi's biggest and beefiest luxury saloon, the S8, gets the option of even more power. Jonathan Crouch checks out what's on offer
Ten Second Review
The Audi S8 now comes with a choice of 4.0-litre TFSI V8 petrol engines. As before, the standard version develops 520PS, but there's now the option of an S8 plus model which puts out a thumping 605PS. Either way, the power is deployed via seven-speed S tronic transmission to all four wheels. While this might sound like a liberal dose of excess, thanks to Audi's efficiency measures it's a lot more responsible than it first appears. Overall, this car is now a touch faster, a touch smarter and a touch cleverer.
The Audi S8 has long occupied a special niche in the supersaloon firmament, a car that just oozes cool. Throughout the years, every version of the S8, from the original 4.2-litre car of 1997 to the 5.0-litre V10 version of 2006, has always had something exotic about it, as if it's operating to a different set of rules. It's the Ronin car, the vehicle that made the ultimate low-profile, high-drama getaway choice. The S8 returned to the UK market in mid-2012 after a couple of years away, still a big car that didn't proclaim its talents too loudly. It was then updated at the end of 2013 in line with the rest of the revised A8 range. In mid-2015, buyers got the option of a more powerful 605PS S8 plus variant and that now sells alongside the standard 520PS model as an alternative for boardroom buyers who might otherwise have been considering models like the Mercedes S63 AMG and the supercharged Jaguar XJ SuperSport 5.0 V8. However you like your S8, there's still the same potent twin-turbocharged 4.0-litre V8 under the bonnet, a powerplant that makes this Audi a very effective long distance express indeed. This is still the genuine article.
The 4.0-litre twin-turbocharged V8 under the bonnet of this S8 might not offer the soundtrack of the previous generation model's screaming V10 but it seems an engine that's a little more in step with the Zeitgeist and one that won't leave many wanting more in the way of power. The 520PS version makes the 62mph sprint in 4.1s en route to the usual artificially-limited 155mph top speed, but many potential buyers are going to want the uprated 605PS S8 plus derivative. Here, you get a massive 750Nm of torque, the highest amount of pulling power you'll find anywhere in the Audi range. For the S8 plus, the sonorous V8 biturbo unit has been extensively modified and gains special engine management control with speed and charge pressure boosting to its modified exhaust valves. The inner geometry of the turbocharger has also been optimised for efficiency. As a result, a mere 3.8 seconds is all it takes for the stately super saloon to blast past 62mph. Buyers are offered an optional dynamic package, where top speed increases to 189mph, as well as fade-resistant carbon-fibre reinforced ceramic brakes featuring brake calipers finished in anthracite-grey with the Audi ceramic logo. Both S8 models of course use quattro 4WD and feature 'Cylinder on Demand' technology that allows the TFSI engine to cut four of the cylinders when cruising to aid efficiency. At low speeds or when driver demands more power, the other four cylinders instantaneously spring back into life. Adaptive air suspension with variable damping can vary the ride height of the body between three levels. Dynamic steering and a sport differential also feature, marshalled by Audi's Drive Select driving dynamics system. The driver can then tune throttle pedal response, shift points of the eight-speed S-tronic transmission, the assistance to the electro mechanical steering and the characteristics of the air suspension.
Design and Build
All S8 models get powerful MatrixBeam LED headlamps which can essentially keep full beam lights on at all times. Aluminium detailing defines the exterior, while there are body colour trim strips on the sills and door handles with strips of aluminium and polished aluminium-look mirror housings. The diffuser insert at the back of the car includes a blade with a two-layer aluminium-look finish offset with parts in platinum grey. The exhaust system ends in two oval dual tailpipes in a chrome-look finish. The S8 plus variant is identifiable by the carbon fibre trim used on the flaps in the side air inlets and the blade on the front apron. The rear diffuser, Singleframe front grille, air inlets and window trims form part of the optional 'black styling package', as do the mirror housings. Distinctive design characteristics of the S8 plus also include darkened tail lights and a rear lip spoiler in body colour. As an option, the mirror housings and rear spoiler can also be specified in carbon fibre. At over five metres long however, the S8 is a seriously big saloon. There's plenty of space to stretch out and a huge 510-litre boot. The multi-way, power-adjustable comfort sport seats were designed exclusively for the S8 and are available in quilted lunar silver at no extra cost. The cabin is smartly finished with stitching and piping in contrasting steel grey, while the upper inlays on the instrument panel and tiptronic selector lever are finished in Carbon Atlas. The leather multifunction sport steering wheel has colour-contrasting stitching and an S8 emblem, which can also be found on the instruments. The illuminated door sill trims with the S8 logo and the S8 welcome screens of the driver information system and the MMI monitor are a smart touch, as are the matching metallic finishes to the shift paddles and pedal set.
Market and Model
The asking price of around £80,000 seems reasonable value in comparison with other super saloons: a Jaguar XJR is £10,000 more while a comparably performing Mercedes S63 AMG is around £40,000 more - though to be fair, the Merc is a long wheelbase car. The LWB option isn't offered to S8 customers. So this Audi is reasonable value. Or at least it is in 520PS guise. The 605PS S8 plus model costs around £98,000. This model is also rammed with the sort of technology this level of buyer expects, the MMI infotainment system featuring Google maps downloads, the ability to select a mobile phone to act as a wi-fi hotspot, plus the display of an infra-red night vision image. 'MMI navigation plus' is fitted as standard and features a touch input system, a large hard drive and a high-resolution 8-inch display. There's also an extended leather package which is complemented by an Alcantara headlining, a DVD changer, the advanced key with a power-operated hands-free opening system and ambient lighting LED headlights and double glazing are also fitted. You need to spend an awful lot more money to buy yourself a manifestly better interior than this.
Cost of Ownership
The S8 might be many things but it's certainly not an inexpensive car to run. Still, fuel economy is one area where you'll probably be pleasantly surprised, that cylinder on demand technology making the car very efficient on long motorway cruises and helping contribute to an overall economy figure of 29.4mpg. The CO2 figure of 225g/km isn't too bad either. These figures are both for the 520PS variant, but the S8 plus model's returns will be very similar. How's it been done? Well it isn't only that the engine's smaller in size. It also benefits from a cylinder deactivation system that disengages four of the eight cylinders under part-load to maximise fuel efficiency. As for the less welcome news, well 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.
The Audi S8 is a car that does so much but makes such little fuss about it. Its buyers like it that way, prioritising capability and discretion. If you want to get somewhere fast and draw no great attention, the S8 is one of the best cars in the business for the task, which is why it's a vehicle so often targeted by those of extremely high net worth. In its current form, this car teases out those themes still further. The V8 engine is a little harder hitting, especially in 605PS S8 plus guise, and the smarter styling will appeal to those who know exactly what those codified design cues mean. It's a car that credits its owner with a bit of savvy. Audi went through a period when things all got a little bit shouty, when it perhaps became a little too strident for its own good. This latest car eases back a little on the big personality and to good effect. Sometimes the car is merely the supporting cast.