Audi RS6 (C8) | PH Used Buying Guide
Outgoing RS6 furthered the model's rocketship reputation - but how does it shape up as a used purchase?
Key considerations
- Available for £63,000
- 4.0-litre petrol twin-turbo V8, 48v mild hybrid, all-wheel drive
- Carries the RS baton of style and performance with pride
- Not economical though, and not free of problems
- Does all the good RS stuff but also quite a lot of the bad Audi stuff…
- … and weakening Audi brand values should also make it more affordable
This week we’re pointing our brass and leather telescope at the 2019-on gen-four (C8) Audi RS6 Avant, which for the first time in RS legend had the benefit of electronic assistance from a 48-volt mild hybrid system.
The headlines from Audi at the time were all about efficiency and economy. They were even talking about the importance of towing, saying that more than half of European RS6 customers were ticking the towball box. That must be a European rather than a British thing because you don’t see that many C8 RS6s with towballs over here. It was all a bit of a chin-stroker when you remembered that the RS6 – which was being built on the Audi Sport line in Neckarsulm – was producing 600hp and 590lb ft of torque from the combination of its 4.0-litre biturbo TFSI V8 and electric motor. Not the kind of numbers you normally associate with horsebox-tugging.
Anyway, Audi was able to back up its planet-saving narrative with a claimed 27 per cent reduction in emissions over the previous C7 RS6, but of course they knew as well as the rest of us that anything with an RS badge on it was bought mainly for horizon-bending performance – and the C8 RS6 had plenty of that. Despite the added weight of its hybrid componentry the C8 had a 0-62mph time of 3.6 seconds, 0.3sec down from the C7’s 3.9 seconds, and its 0-124mph time of 12 seconds was not hanging about by any measure.
Since the C7 RS6, adaptive air was an option to the standard setup of steel springs. On the C8, air was standard with the option of coils. Another change to the C8’s spec was all-wheel steering for better stability at high speeds and more manoeuvrability at low speeds. The 3-inch wider body and 21-inch (or as a first-time option 22-inch) wheels rammed home the performance image that RS buyers wanted.
Talking of performance, in November 2022 Audi announced the RS6 Avant performance, complete with etymologically annoying small ‘p’ at the beginning. Which we'll ignore. The Performance name came in with the 2016 C7 and was the new handle for the old ‘plus’ models. In the C8’s case, the RS6 Performance was a replacement for, rather than an alternative to, the existing RS6 Avant. Larger turbos and a 0.2bar increase in boost pressure to 2.6bar hiked the performance’s power and torque to 630hp and 627lb ft, giving it a 0.2-second shorter 0-62mph time of 3.4 seconds and the title of fastest RS6 ever.
Bang & Olufsen premium 3D audio was standard on the Performance, as were park assist plus, head-up display, 360-degree cameras and 22-inch wheels in matt grey which was the default colour for the external trim pieces. Its RS sport exhaust and Audi rings and badges were in gloss black. Some of the insulation was removed from the car to add aural excitement and there were some new interior features like a blinking shift indicator and door LEDs that projected the legend ‘RS performance’ onto the road.
All the RS6 Performances had faster gearshifting and wider differences between the driving modes, with the coasting mode only activating automatically in the efficiency profile, i.e. at speeds of up to 99mph. They also had the RS Dynamic Package as standard. This lifted the top speed from a limited 155mph to 174mph and added a quattro sport diff to the rear axle. For a good bit more money you could upgrade to the Dynamic Package plus (confused yet?) which gave you 189mph, ligher wheels and a carbon ceramic brake set that reportedly chopped a hefty 34kg off the steel-braked car’s unsprung weight.
Carbon Black and Carbon Vorsprung versions of the RS6 Performance had matt black wheels wearing Conti Sport Contact 7 tyres. The Black has matt carbon styling pieces and Dinamica headlining. The Vorsprung gained Night Vision assistant and carbon twill inlays on top of its already high overall spec which included a panoramic roof. The starting price for the RS6 Avant Performance was £110,000-£112,000 depending on what bit of the internet you believed, compared to just over £92,000 for a non-Performance. Carbon Blacks were £120,000 or thereabouts and the Vorsprungs about £130,000.
In early 2024, Audi announced the RS6 GT, a carbon-heavy (or light) ‘super-estate’ that was essentially a productionised version of the Audi-apprentice-built RS6 GTO concept first seen in 2020. Carbon is used for the bonnet and wings and in the 22-inch wheels. There is also stiffened and lowered suspension, an aggressive aero kit and the option of a classic ‘rally quattro’ style white, red and grey paint scheme. The GT will reputedly have a 0-62mph time of 3.3 seconds, a 0-125mph time of 11.5 seconds and a top speed ‘limited’ to 190mph. Also limited is the number of them being built. As we went to press in mid-April 2024, deliveries of 660 cars worldwide (60 to the UK) were a couple of months away. If you’re reading this as soon as it goes live in late April they’re probably all gone already, at a projected price of about £180,000.
Not for the first time in the recent history of premium German motors that began their lives with price tags comfortably into six figures, there are some interesting deals to be had on used C8 RS6s. We saw one 2023 performance with 11,000 miles on it whose price had dropped by 18 per cent and nearly £20,000 over the course of two months, from £105k in early February to below £86.5k in mid-April. Are they a bargain at that sort of money, or were they just too expensive to start with and they’re still too expensive now?
The Audi brand has been taking a beating of late, a victim of the negative effects of platform-sharing where customers are struggling to see much of a distinction between Audis, Volkswagens and Skodas any more but finding it all too easy to see the sort of faults in Audis that previous experience had led them not to expect. Could these latest RS6s have a lot further to drop? Let’s take a gander. For reference, the recalls referred to in this piece were all in the US. There’s not as much transparency on recalls in the UK so we can’t confirm if UK market cars had exactly the same ones, but it seems likely that there’s a big overlap so we felt we should include them.
SPECIFICATION | AUDI RS6 (C8)
Engine: 3,996cc twin-turbocharged V8 32v with 48v mild hybrid
Transmission: 8-speed auto, all-wheel drive
Power (hp): 592@6,000rpm
Torque (lb ft): 590@2,000-4,000rpm
0-62mph (secs): 3.6
Top speed (mph): 155 (limited), 174 with Dynamic Package, 189 with DP+
Weight (kg): 2,075
MPG (official combined): 22
CO2 (g/km): 283
Wheels (in): 21
Tyres: 275/35
On sale: 2020 - on
Price new (2020): £92,750
Price now: from £63,000
Note for reference: car weight and power data is 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
The 48v mild hybrid system with the battery in the boot was indeed mild. It was a belt-driven starter generator or BSG system designed to assist the 4.0 V8, not to allow you to drive the RS6 about on battery power alone. That wasn’t what the car was about. It was all about rampant thrust facilitated by crampon grip. And of course towing.
With regard to the specific aim of rocketship acceleration on a variety of road surfaces the RS6’s 4.0 V8 didn’t really need any assistance. Its claimed 0-62 figure of 3.6 seconds was easily achieved, and easily repeated, in independent testing. Nought to a hundred took well under eight seconds. On a standing quarter mile, it was only marginally slower than the 200kg lighter 2020 BMW M5 – and you’d struggle to get a family of five with all their ski gear into one of those.
The sports version of the twin oval exhaust was marked out by a black surround. Showing off that pipe’s extra din to your mates wasn’t really on though because a soft limiter prevented you from revving it beyond around 3,500rpm in neutral.
In gentle use, a cylinder-on-demand system shut off four of the V8’s cylinders to boost fuel economy and the stop-start system didn’t have to wait until the car had stopped before it switched the engine off. Despite all that, the average fuel consumption rate was still not what you’d call parsimonious at 22mpg, though it was improved over the C7.
There was a recall in May 2021 for some 2021-model RS6 Avants after cracks on the cylinder bore surfaces were noted. Audi dealers were told to replace the engines free of charge. The 48v system fitted to this and other A6/A7 type Audis has not been problem-free either, with at least one class action lawsuit filed in the US. Hybrid battery drain leading to engine management issues is the usual thing you’ll read about, possibly caused by coolant leaks, condenser failures or capacitor problems. Audi C8 platform alternators have also acquired a reputation for failure, to the point where Audi had to extend the warranty on them. Owners afflicted by this have had to wait weeks or in some cases months for their replacement items to arrive at the dealerships.
Some owners have experienced misfires. One was in the mid gears at midrange revs, another was at lower revs (not much above idle) in damp conditions. Attempts to fix the first car (which had a stage 1 tune) by removing its fuel and cleaning or replacing the injectors were unsuccessful. Attempts to fix the second standard-spec car by replacing its charcoal canister, spark plugs and most of its injectors didn’t work either.
The RS 6’s transmission was the highly-rated ZF 8HP 8-speed torque converter auto. It wasn’t a twin-clutcher because it had become too hard to stop those transmissions blowing up under the onslaught of 600hp and 600lb ft. Luckily the ZF was a great unit with shift speeds that were plenty quick enough for most.
Official C8 RS6 fuel consumption was 22mpg, but the realistic number was 19mpg. In spring 2022 a recall was issued for faulty fuel level senders on the RS6 and a few other A6/A7-based Audis. These senders were sticking, causing inaccurate readings on the fuel gauge. Owners were being told that there was over 150 miles worth of petrol in a half-full tank when in fact there was none. In one case this happened to an owner on his first tank of petrol, leading to pop, bang, judder and total switchoff in the outside lane of the M5 and two hours of standing behind the barrier in the freezing cold waiting for rescue.
CHASSIS
As mentioned earlier, all-wheel steering was standard on the C8, as was air suspension. Slightly stiffer steel coils were the option, or standard on the Vorsprung which couldn’t have air because of WLTP regs requiring features to be bundled up in packs. Some said that the faster you went on the coils, the better they worked. Cars with air suspension moved 10mm nearer to the ground at speeds above 74mph.
Three-stage adaptive dampers and Drive Select let you choose between Comfortable, Balanced and Dynamic suspension settings. Audi’s DRC (Dynamic Ride Control) mechanical pitch and roll stabilisation system worked well with the coilovers but it was a hard ride in Dynamic mode and the DRC could sometimes leave the car looking higher on one side when you got out of the car.
The RS Mode button enabled individual Drive Select combos which provided fine control over the drive, suspension, steering, engine noise and the quattro sport diff at the rear that UK cars got as standard. The evocatively entitled RS2 mode gave you toggleable ESP sport settings.
21-inch wheels with 275/35 tyres were standard, with 22s and 285/30s as the option. Those big rims didn’t materially affect the ride quality and were surprisingly difficult to kerb. The steel brake discs were 420mm front, with ten pistons on each, and 370mm at the back. The front discs of the carbon ceramic system were 440mm in diameter. Despite the amount of rubber on the road, drifting was easily dialled in on the track, although there could be a degree of lurching, which was reasonable enough bearing in mind the weight. It’s tough to apply the word ‘agile’ to any car weighing over two tonnes but as long as you went into it with the right expectations there was a lot of pleasure to be had from behind the wheel of a C8 RS 6, much of it coming from the mad traction and the fabulous feeling of security you got regardless of the conditions.
The Torsen centre diff could send up to 75 per cent of available power to the front wheel or 85 per cent to the rear wheels. UK cars also acquired a sports rear quattro diff as standard. That could send 100 per cent of the power that had arrived at the back axle to either of the rear wheels. It could also develop an oil leak.
A recall in April 2021 addressed rear axle trailing arm locknuts which could break due to stress corrosion. This affected many Audis. Later that same year a lot of Audis were brought in again to check the alignment of the rear axle that might not have been properly inspected after previous recall work, and to replace any tyres that had prematurely or unevenly worn as a result.
BODYWORK
The only parts of the RS6 Avant’s body that were the same as the normal A6’s were the roof, front doors and tailgate. The body was 8cm wider than the regular A6 to accommodate the wider tracks front and rear. The bespoke bonnet meant that Audi could fit the new RS6 with the Matrix LED laser headlights from the RS7. The roof spoiler was slightly larger than it was before and the tail lights were black-effect. The back bumper was new and the front grille sat around 5cm further forward to make room for the V8. Most of the front ‘vents’ were blocked up as Audi’s wind tunnel showed that opening them up didn’t improve the aero so they reverted to being purely styling features, at which they were much more successful.
The pano roof that was standard on the Vorsprung was a two-section affair rather than a one-piecer. It has been known to squeak when in the closed position. Noisy rear wipers have been reported too, and not because the wiper blade was worn. Tailgate motors have failed, as have door lock motors.
As far as colours go, most buyers went for stealth rather than spangliness. Nardo Grey was a popular choice. The Sonoma Green that at least one press car wore (£3,000 extra from Audi’s special paints shop) wouldn’t appeal to everyone but if you liked green cars in a general sense you’d very likely love it.
INTERIOR
The cabin was sleek and expensive looking and the driving position felt good, as did the Alcantara steering wheel. Cabin trim inserts could be in aluminium, wood, or carbon fibre. The sports seats in soft Valcona leather with honeycomb stitching were good too, although there was no massage option available and their high backs weren’t ideal for any vomitous types sitting behind them.
The haptic MMI driver info and mode select screen let you measure all sorts of stuff like lap and acceleration times (0-62mph, 0-124mph, standing quarter and eighth miles). As is the way of things these days, the number of physical knobs was down, a trend not to everyone’s liking, but Audi didn’t go mad on that in the same way that VW did with the Golf GTI. The RS6’s screen menus gave you quick access to what you wanted with plenty of shortcuts and of course you also had the RS Mode button on the steering wheel.
Buyers coming into the 2020 C8 from the C7 would almost certainly notice a reduction in cabin noise in the newer car. The removal of some sound insulation from the 2022 performance model suggests there may have been some negative customer feedback about that from serial RS buyers. AMG Mercs were noticeably rowdier. The jutting under-dash that housed the infotainment screen looked like something that might creak and rattle given half a chance but there don’t appear to have been too many complaints about that. However there have been a few grumbles about an almost subliminal noise coming from the rear cabin somewhere, usually after hitting a bump, and about Audi’s change from a round dial tachometer design to a sort of hockey stick graphic.
There was tons of room in both the rear passenger and the boot, which had 565 litres with the rear seats in place. The boot of the Mercedes E63 S estate was even bigger mind you, at 640 litres. There was a recall in August 2021 on this and many other Audi models to inspect and replace as necessary faulty locking retractors on the middle rear seat belts which could prevent the correct operation of the child restraint system. Earlier that same year a recall was put out to repair improperly manufactured score lines on the passenger airbag. Again that affected quite a few Audi models, not just the RS6 Avant. A smaller number of Audis (including the RS6) had been brought in at the end of 2020 to replace or secure crash sensors in the front doors, which could detach.
At the end of 2022, a recall was issued for 50,000 A6 and A7-based cars including the RS6 Avant and the RS7 when it was discovered that an unprotected control module under the back seats could lead to short circuits and a switch to reduced-power emergency mode if any liquid came in contact with it. The solution there was to put a cover on it.
Some ‘gateway’ modules have failed. These were responsible for comms within the vehicle’s data network system. Some cars have developed intermittent knocking noises from the centre console that it’s thought might have been coming from two flaps for the climate control systems. Confirming that, or not, was a big job. At least one owner experienced failure of a steering column motor. The wheel would telescope in and out, but not up and down.
PH VERDICT
The C8 RS6 fully maintained the RS sub-brand’s established reputation for understated but crushing performance. There was a good dollop of practicality in there too and the ride was comfortable. At normal speeds, it would carry five people and all their gear with no bother at all, just like any other A6, the battery of driver aids making light of life behind the wheel on the motorway. The Pre-sense lane assist could be an intrusive pain on other roads until it eventually worked out you didn’t want it and stopped re-engaging itself every time you got in. The adaptive cruise was great for packing away the miles, but Audi’s decision to charge extra for that as part of the Tour pack on a car that was already very expensive did seem a bit cheeky to some.
When you were driving solo it could be an entirely different beast, but it was too well-balanced a car to be burdened with the old ‘Jekyll and Hyde’ epithet. It was just brilliant to have the choice. However you drove it, there was a feeling of quiet, not to say smug, satisfaction. Despite the cylinder shutoff tech, it wasn’t massively economical, but it was a 4.0-litre twin turbo after all and you can’t have everything in life. Well, some can, but they’ll generally own more than one vehicle and they probably won’t be that bothered about fuel consumption.
As you may have picked up from this story the C8 RS6 has had its fair share of problems. One owner who actually hadn’t had that many issues with his car went onto the RS246 site to say that he was getting rid of it because the shine had worn off after six months but the running costs hadn’t gone down and he had begun to ask himself why he hadn’t saved £60k by getting a well-specced A6 instead.
That apart, the 6 is a great do-it-all choice if you want RS bragging rights and don’t fancy the Mercedes-AMG or Porsche Panamera alternatives. Few truly dislike the RS6’s looks, even if it wasn't automatically better looking then its predecessor. If you’re the get-out-and-about type wanting one vehicle to do everything in all weathers and in more than one country you should certainly have it on the very shortest of your shortlists, but be aware of the possible problems and negotiate hard on the price.
We posed the question in the introduction as to whether these cars are overpriced. Base versions of the first pre-performance 600hp cars cost somewhere in the low £90k range when new, which was less than the Mercedes-AMG E63 S. There has been depreciation, but the rate seems pretty normal. It’s certainly nowhere near the level of value drop suffered by all-electric Audis like the e-tron GT.
The cheapest 600hp C8 RS6 we found for sale in the UK at the time of writing in April 2024 was a 2020 Vorsprung with 76,000 miles on the clock and a price tag of just under £63,000. The most accessible one on PH Classifieds was this 2020 Carbon Black with 49,000 miles at £63,995 but that one was sold just as we went to press, promoting this stealthy 2021 38,000-miler into the cheapest PH RS6 spot at £64k on the nose.
You’re going to be needing quite a bit more cash for a 630hp Performance model, not just because they have more power but also because they’re newer (2022-on) and have smaller mileages. The lowest-priced one we found anywhere was the one we were talking about earlier, this ’23 11,000-mile example in red for just under £86,500. That’s not a typical price though. More usually you’ll be paying at least £100k. So what’s going on with that one? There might be something very annoying wrong with it, or it could be the shouty colour. These fast Audis have always been a magnet for thieves and red will draw them in like flies around cow poo. Maybe it’s just an anomaly. Either way, if you were going to look at a £100k RS6 Performance it might be worth printing out the ad for the £86k one and giving the sales bod flogging the £100k car a quizzical look. Or you could buy the £86k car, hope it’s not got a problem and invest a couple of grand in a wrap.
You can pay a lot more than £100k if you want. In the course of our ad scraping we saw a delivery mileage ABT RS6 Legacy Edition (based on a Vorsprung but with lots of ABT chassis, carbon and go-faster bits taking it to 750hp) priced at £245,000.
We saw one 2023 performance with 11,000 miles on it whose price had dropped by 18 per cent and nearly £20,000 over the course of two months, from £105k in early February to below £86.5k in mid-April. ”
Am I so badly out of touch that a £20k price drop / depreciation is deemed ‘pretty normal’..?
Much as I want to like, nay, love these, I can’t.
Perhaps I’m more suited to an RS4 or similar, as these just leave me cold, perhaps it’s the size (and I mean the width) of the thing.
My other concern would be how long I’d actually get to keep it, as mentioned the seem to have an odd attraction to the sort of people who want to have it without paying for it.
I went back to a B8 RS4 - lovely N/A V8, a much more reasonable size for UK roads and more realistically paced for our roads.
Fuel economy is not terrible, 30mpg+ on a motorway run. Low to mid 20s otherwise. I've been looking what to replace mine with and I think I might just get another one. An Alpina would be nice but you never see them.
In my opinion all performance cars benefit from an aftermarket exhaust I think, and I've put an aftermarket exhaust on quite a few of the performance cars I've had over the years. Not only do they enhance the noise, but they also get the car breathing better as well I reckon.
My 370Z would be as quiet as a mouse if it still had the standard exhaust on it for example, and my F82 M4 is properly quiet on its standard exhaust as well frustratingly. If a car has a reasonably sized engine under the bonnet, then I personally want to hear it...can someone give me back my TVR Cerbera 4.5 on its factory supplied sports exhaust please?!
Toyota can make hybrids reliable, we've seen plenty of evidence of that. They don't have cylinder deactivation and the like, though.
I feel like a 'cheap' one of these outside of manufacturers warranty might be a very expensive way to own one indeed.
The dash rattles in the C8 A6 are well known to the point Audi don't quibble, dealer already had 2 goes at mine and booked in for a 3rd attempt.
In RHD cars the ZF8 gearbox intrudes into the pedal area making the car uncomfortable on longer journeys, your left leg needs to be several inches longer than your right to touch the footrest.
Not sure if the RS6 suffers with gearbox lag like other Audi's fitted with the ZF8 but the article doesn't mention this.
The overall ergonomics in this car are beyond awful with everything on a touch screen, software features that just don't work despite updates. Cannot get a comfortable driving position, still problematic after 18 months.
The BGS repair is about £3k if parts are available but there is little indication of the fault until you lose all power wherever you happen to be.
Honestly a car to avoid, I am sure Audi are pleased with the positive write-up but anyone buying one based on this will review be disappointed in the long term.
In my opinion all performance cars benefit from an aftermarket exhaust I think, and I've put an aftermarket exhaust on quite a few of the performance cars I've had over the years. Not only do they enhance the noise, but they also get the car breathing better as well I reckon.
My 370Z would be as quiet as a mouse if it still had the standard exhaust on it for example, and my F82 M4 is properly quiet on its standard exhaust as well frustratingly. If a car has a reasonably sized engine under the bonnet, then I personally want to hear it...can someone give me back my TVR Cerbera 4.5 on its factory supplied sports exhaust please?!
Gassing Station | General Gassing | Top of Page | What's New | My Stuff