Audi S8 (D5) | PH Used Buying Guide

Fast, subtle, luxurious and reliable, there's plenty to recommend the S8 - especially at half its price when new

Key considerations

• Available for £55,000
• 4.0-litre petrol twin-turbo V8, all-wheel drive
• Supercar-fast but still a wonderfully refined cruiser 
• Predictive suspension works well
• Not cheap to run but superbly built and very reliable
• Best driver’s S8 yet, and depreciation is making them affordable 

Once upon a time, a car was something with two or four doors, seating for four or five, and a separate boot to carry a few pieces of hard luggage. That car was called a saloon, from the French word for a living room. The arrival of the hatchback and the inflation of estates into SUVs brought saloon sales down to a point of near-extinction in the UK. However, there have been enough customers around – hospitality businesses and posh taxi operators as well as private owners – to keep the ‘living room on wheels’ idea alive. 

In Europe and elsewhere the four main players in this small but still significant market – Audi, BMW, Mercedes and Jaguar – have done quite nicely out of their high-end, high price and therefore high-profit saloons. Audi’s big saloon offering, the A8, made big headlines on its debut in 1994 thanks to its ‘Audi Space Frame’ aluminium bodyshell that allowed the car’s weight to be kept low (not much more than 1.5 tonnes in one variant) without compromising its strength or integrity. 

By the time Audi had added quattro all-wheel drive to the A8 in 1997 the S8 performance version powered by the firm’s fine 4.2-litre V8 had already been on sale for a year. 2024 is the 30th anniversary of the A8 so it seems fitting to do a buyer’s guide on the fourth-generation D5 S8 that was announced in the first quarter of 2019. 

Featuring a 570hp/590lb ft twin-turbo 4.0-litre TFSI V8 and a 48v mild-hybrid system the gen-four S8 was actually 34hp less powerful than the pokiest gen-three S8, the Plus, although an engine rework and an increase in turbo boost pressure to 1.8 bar made the new car 37lb ft more torquey than the old Plus. The 8-speed Tiptronic torque converter gearbox was beefed up for the new car and a ‘sport’ diff was added to give constantly variable side-to-side torque vectoring at the rear. Up to 70 per cent of the transmission’s output could be put through the front wheels and up to 85 per cent through the rears. 

The biggest advance for the new S8 was the Predictive Active Suspension which Audi claimed was the most advanced they’d ever used on a production car. Electro-mechanical actuators responded to information gathered by a road-scanning camera behind the cabin mirror to prompt the suspension compressor into optimising ride heights at each corner of the car. There was more to it than that too, which we’ll get into in the Chassis section.  

A midlife refresh in 2022 brought a new and even bigger grille with a new S8 design, digital matrix lights, OLED taillights, reshaped sills and chrome-trim bumpers, a pretty rubbishy fake diffuser, three-spoke (ish) steering wheel, nine new paint colours including five matt ones and some new design choices for the wheels that were 21-inch for both Black Edition and Vorsprung cars. Black Edition cars had, unsurprisingly, a black exterior styling package with black wheels and black Audi rings. Vorsprung range-toppers had a lot more substance about them, including as standard the Technology Pack Pro which gave you heated seats all round, massage/ventilation front seats, pano roof, central rear control unit, USB ports with charging function in the rear, four-zone climate, carbon exterior mirror housings, Parking Assist pack plus, ‘laser’ lights, and an entry LED projecting ‘Vorsprung’ onto the ground when the door was opened. That pack was available separately for £3,995. At that point in its career the base S8 was £102,730, the Black Edition £105,730 and the Vorsprung £117,730.

This will be the last internal combustion engined S8 as Audi concentrates on its all-electric replacement for the A8 but if you want a new S8 in 2024, that’s no problem, it’s still on Audi UK’s website as a new car. Although there’s no limit on production as far as we’re aware, they are effectively limited editions simply because the number of customers is so limited. Audi’s advertised on-the-road price for a standard S8 in July 2024 was £111,800, up from £100,000 in early 2021, putting it in the same sort of ballpark as the AMG E63. BMW’s M5 and Porsche Panamera GTS are more expensive. The Vorsprung is now £122,550 on the road but S8s in any guise lose value faster than any of its German rivals. The average S8 buyer wouldn’t be paying anything like recommended retail. Big discounts were available from new. 

Unsurprisingly, this reluctance to pay the RRP impacts used values down the line. Most of the stock you’ll see on the British used car market – typically between 10 and 20 cars at any given moment – is priced in the £65-£70,000 range, but we would expect dealers will be pretty tolerant of offers. The cheapest car we saw on sale in the UK in July 2024 was a 2021 Vorsprung with 31,000 miles on it, priced at just under £55,000. The most expensive example we found was a ’23 Black Edition with 1,750 miles at nearly £85k (reduced from £92k four months earlier) but there were also two lower-mileage ’24 Vorsprungs at a smidgeon under £83,000 each. 

Although the gen-four S8 was announced in early 2019, with the order book meant to be opening in the late part of that year, we couldn’t find any UK cars for sale that were registered before 2021. The base model looks like a ghost machine that nobody bought.   

SPECIFICATION | AUDI S8 (2020-on) 

Engine: 3,996cc twin-turbocharged V8 MHEV
Transmission: 8-speed auto, all-wheel drive
Power (hp): 570@6,000rpm
Torque (lb ft): 590@2,000-4,500rpm
0-62mph (secs): 3.8
Top speed (mph): 155 (limited)
Weight (kg): 2,305
MPG (combined): 24.6 (Vorsprung 24.4)
CO2 (g/km): 261 (Vorsprung 263)
Wheels (in): 9 x 20 (Black Edition and Vorsprung 21)
Tyres: 265/40 (265/35 on 21)
On sale: 2021 - on
Price new (2024): £111,800
Price now: from £55,000

Note for reference: car weight and power data are hard to pin down with absolute certainty. For consistency, we use the same source for all our guides. We hope the data we use is right more often than it’s wrong. Our advice is to treat it as relative rather than definitive.  

ENGINE & GEARBOX

On power and torque, the 570hp/590lb ft S8 sat between the 530hp/553lb ft BMW 750i and the 612hp/664lb ft Mercedes S63. Compare that to the 360hp/317lb ft gen-one S8 which needed not far off twice as much time to hit 62mph from rest. 

As you’d expect from a late 2010s car the 4.0 V8 had a cylinder deactivation system to cut fuel consumption on small throttle openings and a regen system that in this case could gather up to 8kW on braking and coasting. The official mpg figure was around 25, but it wasn’t easy to get much more than 21mpg even in gentle driving. That and an 18-gallon tank restricted you to between-fill runs of 350 miles or less. 

Typical owners would probably be more engaged by the way the car romped up the road. The official 0-62mph time was 3.8sec, but independent testers in the UK have managed to do the slightly shorter (but not by much) 0-60mph run in 3.2sec, equating to a 0-62 of maybe 3.4sec. At least as impressive was a 0-100mph time in the very low eights. You had to give a lot of credit to the Audi engineers who had so brilliantly matched the engine and the syrupy smooth 8-speed Tiptronic gearbox to the quattro system and to the phalanx of driver aids and modes.  

Tank range apart, the S8’s supercarish performance – it was nearly as quick as the R8 – could still make it a brilliant continental express as long as that performance went hand in hand with equally good dynamics and comfort. We’ll get into whether it did that in the Chassis section which comes after this one. 

Some owners of D4 (gen-three) S8s had issues with the oil strainers which starved turbochargers of lubrication, causing bearing wear, but we’re unaware of any such problems on the gen-four. There was a recall on very early (’00-’01) S8s to put a sealing pin into the ECU module connector to stop water getting in. As usual with complicated, systems-packed modern cars it was vitally important to keep the S8’s battery in prime condition. 

Audis that are less than three years old seem to qualify for the firm’s Smart Service Plan package which gives you up to 4 years’ worth of care. The car tells you when it needs attention, which might not be for up to 2 years or 18,600 miles. We can’t tell you exactly how much dealer servicing costs because Audi doesn’t publish that information online, and you might need a lawyer to interpret the small print, but we reckon that the first owners would have paid £350-£400 to cover dealer servicing for the first three years. Audi’s ‘Bumper’ scheme allows you to pay larger bills of up to £5,000 in up to nine interest-free monthly chunks. Extending the three-year warranty to four-year/75,000 miles costs £1,160. For 5 years and 90,000 miles the cost is £2,850.

CHASSIS

30 years on from the first A8, the structure containing everything that makes an S8 was still called an Audi Space Frame. The name didn’t change, but what did change, and quite significantly in the gen-four S8, was the driving experience. 

Pushed hard along a twisty road the previous gen-three S8 was relentless in its pursuit of understeer, pre-determined as it was by the safety-first settings of the quattro system, but the gen-four with its PDE predictive suspension system was a different kettle of fish. It got your attention even before you got the car moving, lifting the body up by 50mm when the driver’s door was opened to ease your entry and exit and lowering it back down again once the door was closed. 

But it was on the road where the benefits of PDE really shone. In Dynamic mode it cut body roll through corners to a maximum of 2.5 degrees, around half the amount of lean that would normally occur in a car fitted with conventional steel suspension. In Comfort+ mode it positively leant the S8 into a corner, motorcycle style, by up to 3 degrees to negate the sometimes uncomfortable seat-slide you might otherwise be experiencing. It also counteracted longitudinal pitching over sleeping policemen and the like. More mature readers may remember similar arrangements in the Citroen Activa of the mid-1990s and the Toyota Soarer Active from the early ‘90s.  

The other key piece in the S8’s jigsaw was its rear-wheel steering, which as an aside wasn’t available on the S-Class. The sharper turn-in that provided allied to the wonders of PDE delivered a fine blend of responsiveness, fluidity, and stability on both bends and straights. The dynamics were especially admirable because it was all happening in a limo-class car weighing the best part of 2.3 tonnes. Despite the S8’s size, the rear-wheel steering played a useful part in subduing the intimidation factor in towns and cities. 

It all came as a very pleasant shock to anyone who hadn’t driven an Audi since the bad old days of numb steering and nobbly rides. It wasn’t quite magic-carpet perfect – bigger road imperfections weren’t absorbed as effortlessly as they were in some Rolls-Royces – but it was more than a match for any of its main rivals. The gen-four was arguably the first S8 you could enjoy as much from the front seat as you could from the back one. 

Carbon ceramic brakes (420mm front with 10 – yes, ten – pistons, 370mm rear) were a rarely chosen option. In fact, they were never chosen by UK buyers because they weren’t on the options list. A recall was issued in early 2022 to check the alignment of the rear axle which could create uneven tyre wear.  

BODYWORK

S8s have never looked radically different to regular A8s and the D5 version continued that tradition. The main points of differentiation between the S8 and the A8 were the front bumper, bespoke grille, metal-finish door mirror housings and four-tailpipe rear. The new S8’s boot badge looked pretty much identical to the one on the boot of the first-generation S8, a nice touch.  

A long-wheelbase variant joined the S8 range for the first time in the gen-four but as with the carbon brakes this wasn’t made available in the UK. You could get an ordinary A8 in a long fitting though, so you did have a choice between that and BMW’s M760Li. Soft-close doors were standard. The panoramic glass roof that came with the Vorsprung could be optioned at £1,650.

At around the same size as the S-Class Merc’s, the S8’s 505-litre boot was more than big enough for Jason Statham to transport human passengers and to dismiss any doubts you might have about the practicalities of running a saloon. Shame there was no rear seat split-fold function. There was a load-through hatch but that had to be specially ordered and paid for at £205. A recall was put out in late 2021 to rectify a software error that was causing a delay in the arrival of the rear-view camera’s image display when the S8 was put into reverse.

INTERIOR 

The S8’s cabin was always a thing of beauty, so it was to everyone’s relief when the gen-four came out having not fixed what wasn’t broke. Materials and construction were fabulous, better (some said) than those found in the Mercedes S-Class. Some aluminium and carbon trim pieces were added to the S8, specifically a ‘Carbon Vector’ upper inlay with a 3D depth effect and another inlay of dark brushed matt aluminium below it. None of if was overdone. The headlining was Alcantara.

Standard 22-way sports seats with four-stage lumbar support were huge and hugely comfortable. They came in either Valcona or Unikat leather and had pneumatically adjustable side bolsters and three-stage heaters. Massage and ventilation option boxes were frequently ticked.

No fewer than 38 driver assistance systems were included in the S8, divided into City and Tour packages. Tour was standard on all UK-spec A8s and included adaptive cruise assist, combining adaptive cruise, traffic jam assist, lane tracking and the satnav-linked predictive efficiency assist to brake and accelerate the S8 according to road conditions. The City Assist pack (standard in the Vorsprung, £1,375 otherwise) added pre-sense side to pre-sense back and front, resulting in 360-degree monitoring of traffic coming at you from all angles and preparing the vehicle for impact by closing the windows, tightening the seat belts and illuminating warning lights for other road users. Better still it worked with the PDE system, lifting the body by up to 80mm in an upcoming crash situation to put the strongest parts of the sills in the firing line.  

A fully equipped S8 had five radar sensors, six cameras, twelve ultrasound sensors and a laser scanner. Eeeh, you don’t get as much kit as that in some Currys outlets. Traffic Jam Pilot was being talked about at one point but we’re not sure if it ever made it onto the S8’s spec sheet. Offering Level 3 autonomous driving in ‘heavy traffic’, i.e. at lower speeds below 37mph, it was deemed unsuitable for release in the US. 

The 12.3-inch Virtual Cockpit was as lovely as ever and two haptic feedback touchscreens (10.1-inch top, 8.8-inch below) took care of just about every infotainment function. Selection could be a fiddly process but the feedback helped to confirm your finger presses and you could always fall back on voice control via the integrated Alexa service. The 19-speaker 755-watt audio was by Bang & Olufsen and sounded fantastic, but if you really wanted to blow passengers’ minds you could spend £5,400 for an upgrade to a 23-speaker, 1,920-watt B&O 3D Advanced Sound System. 

Both Android Auto and Apple CarPlay were supported, wireless charging was included and there was a head-up display too. Car-to-x services that drew on the swarm intelligence of the Audi ‘fleet’ on UK roads included a search for street parking spaces as well as traffic sign info and hazard alerts. Oddly you had to pay £250 for a heated steering wheel even in the Vorsprung. Maybe that’s an indicator of the number of owners who actually sat in the driving seat of an S8. 

Power-triggered exhaust flaps let you enjoy the V8 sound, more of it in decibels than that produced by the gen-one’s 4.2 V8, but if peace and quiet was what you needed the active noise cancellation integrated into the gen-four’s sound system made it eerily quiet at cruising speeds. Overall refinement with double-glazed windows as standard was exceptional. 

PH VERDICT

It took a while, nearly thirty years, but in the gen-four S8 Audi finally found the mix of performance, handling and comfort that buyers might have been hoping to experience in the three previous iterations. If those hopes were based on what they’d seen in Ronin they were going to be disappointed because those dabs of oppo were achieved by line-lock equipment that had been added by the stunt crew. 

With a worthy connection between car and driver finally established the gen-four S8 could at last live up to the badge promise. You could say it over-delivered on that because the passage of time and the demands of aero efficiency gave the back end in particular a more stately look than that of the gen-one. Many will say that the first S8 was the most handsome model, but in every measurable way and also in the less easily measurable ones like refinement the gen-four was streets ahead of its granddad.

Of course, the gen one S8 is somewhat easier to buy, high-milers going for as little as £3,500 in mid-2024, whereas the cheapest gen-four will cost you around £55k. Still, that’s a bit of a bargain when you consider you’re getting a 3-year-old S8 for more or less half the sticker price of a new one. It’s another demonstration that depreciation can be the friend of buyers who appreciate superb quality, high technology content and a very satisfying driving experience. 

The gen-four S8 was as rapid as most of Audi’s RS tackle but nowhere near as shouty about it. For some it might not be shouty enough. Visually, the ’22 refresh was a touch more aggressive than the model it replaced but if you wanted all-round bombasticity (which is not a word) you’d be popping into the AMG showroom for an S63. That car wouldn’t depreciate as hard as the S8 either. 

What the S8 has going for it though is reliability. We searched in vain for moaning owners. One independent complaints-dedicated website ranked the whole S8 series from the gen-one to the gen-four as number one for reliability out of 19 Audi models they looked at, with just two complaints being raised in 20 years.

On PH classifieds at the time of writing this Black Edition with 14,000 miles was the most affordable S8 at £65k. Two of the ten cars for sale on PH were Vorsprungs. The cheapest one was this ’22 car with 7,000 miles at a whisker under £73k.The most expensive S8 on the site was this Ultra Blue ex-demo Vorsprung with just 1,000 miles for just under £83k.

See every S8 for sale