2021 Audi RS6 v Mercedes-AMG E63 S comparison

Five years ago, this wouldn’t have been close.

Our test route winds deep through Gippsland farm country and the roads aren’t just intermittently wet but full of environmental hazards: tree litter from recent storms and mud from roving tractors mixed with some special surprises left behind by the local cow population.

The Audi RS6 is made for situations like this. No matter the weather or road surface it’s never flustered, deploying more of its virtually endless power reserves than you ever thought possible. For almost 20 years it’s been thus. On the other hand, the Mercedes-AMG E63 S has traditionally preferred warmer climes.

Fast E-Classes have always been near the top of the tree when it comes to horsepower but putting it through just the rear wheels made them a wet newspaper to the RS6’s hardwood two-by-four when it came to effectiveness in conditions like these.

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That all changed with the arrival of the W213 in 2017. This was Australia’s first exposure to a 4MATIC E63 (left-hookers had been around since 2013) and it totally changed the model’s character. Not only did it transform its tractive capabilities, but AMG took the opportunity to redefine what an E63 was.

Whereas previous models – from E36 to E55 to E63 – had been high-speed cruisers but dynamically inferior to, say, BMW’s M5, the W213 was a genuine four-door supercar, capable of 0-100km/h in 3.4sec and tearing up a racetrack to boot.

Its incredible performance landed it second place at Performance Car of the Year 2017 but, ironically, it was the other end of the spectrum that possibly cost it the win. By injecting its newest E63 S with the distilled essence of AMG, it left arguably too much of the Mercedes behind.

While phenomenal to drive hard, the car never wanted to relax; the ride was firm, impacts would thud and buzz through the bodyshell and it always felt to be egging you on to stick it in Race mode and drive like your pants were on fire. Great for an AMG, not so much a $250,000 luxury Mercedes sedan.

Somebody quite high up at AMG has obviously had similar thoughts. It might even have been former boss Tobias Moers, who recently departed AMG to head up Aston Martin.

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''The RS6 is made for this. No matter the weather or road surface it’s never flustered''

In a recent interview with our sister title Wheels, Moers responded to a question that AMGs have often felt too stiff outside the smooth roads of their German homeland: “I know that now. British B-roads are different! You should not tie the body down too much.”

Recent Affalterbach products have been noticeably more comfortable than their predecessors, namely the C63 S and new A45 S, and now it’s the turn of the E63 S.

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The tagline for the E63’s recent facelift is “Comprehensively updated exterior, interior and ride comfort”.

At the front there’s a larger grille and narrower headlights, like the car is suspicious of something, while at the rear the tail-lights are now horizontal, stretching into the boot, rather than vertical – much closer in style to its W212 predecessor.

I can’t personally decide if it’s an improvement or not. The somewhat understated spec of our test car doesn’t do it favours – it takes the sleeper vibe a step too far for mine – but a play on the configurator suggests a colour and wheel change ups the menace.

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It must be said, however, that attempting to out-butch an Audi RS6 is a bit like hitting the gym next to prime Arnie – you’re virtually guaranteed to come off second best. The Audi is actually only 44mm wider than the Merc, but the way the body flexes out over the gargantuan 22-inch rims gives it enormous presence. It’s possible to confuse the E63 for a more humble variant, but there’s no mistaking the RS6’s purpose.

The wagon bodyshell does its cool score no harm, as well as giving it a practicality advantage. With rear seats in place it offers 565 litres to the AMG’s 540 litres (though we suspect that figure doesn’t load the Audi to the roof), but drop the rear seats and the RS6 swallows 1680 litres.

The two interiors are markedly different in design and execution. You sit relatively high in the RS6 with plenty of space in the footwell. It’s a great cabin, simple and classy. The vast majority of the buttons have been replaced by screens – two in the centre for HVAC and infotainment, a third for the instruments – but somehow it doesn’t feel like tech overload.

Audi’s MMI is slick and intuitive and the thin-rimmed steering wheel with its clear buttons is the polar opposite to the AMG’s, which I’ll come to in a moment. The Alcantara covering – part of the $2900 RS Design Package, which spreads Alcantara, Nappa leather and red highlights throughout the interior – isn’t usually a good idea in road cars as it reacts to the oil in your skin over time, but the RS6’s wheel shows no signs of wear after 10,000 press kilometres.

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In addition to the RS Design interior treatment, our test car wears the $8700 ‘Carbon & black exterior package’, which as the name suggests smatters the exterior in carbon and black, the $11,000 ‘Sensory Package’ (awesome 19-speaker Bang & Olufsen stereo, Alcantara heading, leather airbag cover, heated outer rear seats, rear sunblinds), gloss black badging ($700), carbon twill inlays ($1700), big-ticket $19,500 RS Dynamic package (carbon ceramic brakes, 305km/h top speed) and $2850 RS sport suspension, which replaces the standard air springs with steel and includes diagonally linked dampers to reduce pitch and roll.

In standard guise the $216,000 RS6 has a handy price advantage over the $253,775 E63, but as-tested the unadorned Mercedes is cheaper than the $263,350 Audi. What’s $10K when you’re talking a quarter of a million?

You sit lower and deeper in the E63 in seats that are firmer but more supportive. The transmission tunnel intrudes into the footwell and the new AMG Performance steering wheel is offset slightly to the left. It’s a beast of a thing, the super-thick rim too chunky for my tastes, though the new manettino-style drive mode controller is both flash to behold and easy to use, allowing the adjustment of all manner of vehicle functions on the fly.

The swipeable haptic sensors, which control the volume, cruise control speed and dual 12.25-inch screens, are decidedly less successful. They work OK for simple functions like volume or navigating the instrument cluster, but the fine control required for working the infotainment becomes an exercise in frustration with inputs frequently ignored. Thankfully, the central trackpad is more successful, but the MBUX infotainment isn’t as user-friendly as Audi’s MMI.

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It doesn’t take long to realise Mercedes has made real strides in comfort and refinement. It’s still firm and certainly no magic carpet, but it rounds off bumps and lumps and no longer are impacts heard and felt in the same manner. Combine this more relaxed demeanour with toasty seat warmers (front and rear) and benchmark assisted driving technology – that new steering wheel has pressure sensors in the rim so it knows when you’re holding it, removing the need to wiggle the steering to keep lane assist active – and the new E63 S finally delivers on the Mercedes end of the deal.

There’s still room to improve at low speed, though, the nine-speed auto occasionally slow to react and the front wheels chattering as they skip across the road at full lock.

The Audi’s damping is softer, the RS6 less concerned than the E63 S with body control in Comfort mode, but the ride is compromised. Speaking to colleagues who have sampled the standard air-sprung RS6, it seems some of the blame must be apportioned to the steel springs of the RS Sport suspension, but the heavy-footed response to potholes and road imperfections suggests those giant wheels must shoulder some responsibility. It takes the shine off the experience somewhat, as high- or low-speed, the car rarely settles for any length of time.

It’s just as well that the Audi delivers on the other side of the ledger, then, with handling prowess that’s difficult to countenance with a car of this size. The RS6 must be as dense as a dying star, as despite being roughly the same size as the E63 S it weighs almost 200kg more at a whopping 2075kg.

Audi has employed high technology in a – largely successful – effort to counteract this bulk, with rear-wheel steering and a very clever all-wheel drive system. The steering is very quick, particularly off-centre, so inputs need to be measured; resistance is light and initially it feels quite numb, but as the front tyres begin to slip across the road the level of feedback increases.

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Some experimentation is required to set the RS6 up to its optimum, a couple of favoured settings combinations then able to be saved to the ‘RS1’ and ‘RS2’ modes activated by the RS button on the steering wheel.

Steering weight is likely to be personal preference, as thankfully selecting Dynamic no longer turns an Audi’s helm into a syrupy mess; drivetrain in Dynamic is a no brainer, ESP in Sport likewise, but the dampers must remain in Normal as selecting Dynamic makes them far too stiff, bumps bouncing the car clear of the roads at times. Normal retains acceptable levels of body control with increased compliance and the little extra roll makes it easier to read the RS6’s behaviour.

In these slippery conditions the Audi is brilliant. It takes up a lot of the road but can be placed accurately and with confidence. The rear-wheel steering proves its worth with mid-corner rotation; from there the throttle does the rest, with enough power being sent to the rear wheels to complete the rotation and offer a wiggle of oversteer on exit.

It’s not only brutally effective but bloody entertaining to boot. Tackling the same section of road in the E63 S is a hair-raising affair. Attempting the first corner at what feels roughly the same speed as the RS6 managed, the rear end steps out sharply, the resultant ESP intervention then sliding the front end out.

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It’s immediately apparent that in the wet the Mercedes can’t find anywhere near the same level of grip as the Audi. Why that should be is somewhat of a mystery. Both cars wear identical Pirelli P Zero tyres of roughly equal dimensions – the RS6 has 285s at each corner, whereas the E63 S is staggered with 265s front, 295s rear – so presumably the difference is down to drive logic and geometry. Despite its slight softening, the AMG is still clearly the more aggressive car, its setup beginning to pay dividends as the road dries.

The steering is slower off-centre and weightier but also more organic with greater communication, an observation that similarly applies to the rest of the car. Whereas Audi has cleverly given the massive RS6 a sense of agility with some clever toys, the E63 S possesses the traits inherently. To drive hard it is, frankly, stunning for a car of this type.

The nearer you get to the limit the more it separates itself from the RS6, eventually becoming chuckable in a way the massive Audi can’t replicate. Sport+ damping is now perfectly judged for difficult roads, keeping the car’s still-substantial 1880kg mass under control but without hopping and skipping over sharper bumps. Turn-in is immediate, front-end grip tenacious, mid-corner balance tremendous and traction almost unimpeachable. Only the brakes trail the Audi’s, needing a greater push without offering the same feedback, though by any objective measure they are still hugely powerful.

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Not as powerful as the engine, though. The 4.0-litre twin-turbo V8 is a force of nature, with a whopping 850Nm spread from 2500-4500rpm, but it’s the top end ferocity that takes your breath away. Just as your body begins to adapt to the longitudinal force being applied the rate of acceleration increases again as the tacho needle rips through to the 7000rpm redline.

Activate launch control and the whole car vibrates with potential fury. Lift the brake and it explodes off the line; several runs are needed to lay down enough rubber on the slippery strip to stop ESP killing both the wheelspin – yes, even with all-wheel drive – and any chance of a good time, but eventually the E63 S clocks an impressive 3.51sec 0-100km/h and 11.52sec 0-400m at 198.11km/h. Ludicrous numbers, though we did manage 3.40sec and 11.28sec at 203.72km/h respectively in the pre-facelift car at PCOTY 2018 – environmental factors or is the updated car a bit heavier?

Regardless, the RS6 isn’t as quick, but let’s keep a little perspective here, shall we? Activating launch control is a bit of a process, with the need to select this and deactivate that, but it’s every bit as effective as in the Mercedes. The revs hover at around 5000rpm until road speed catches up to wheel speed, followed by a relentless charge, each gearshift thumping you aggressively in the back.

At 80km/h the two are neck and neck – no, I mean it, they clock exactly the same 2.58sec – but from there the AMG begins to edge away, a 0.05sec deficit at 100km/h (3.51sec vs 3.56sec) increasing to 0.72sec by 200km/h (11.72sec vs 12.48sec). At the end of the quarter mile the RS6 clocks a still-impressive 11.64sec at 193.44km/h, but it clearly trails the E63.

Likewise, its 2.2sec 80-120km/h punch is a tenth slower than the AMG’s, but it turns the tables under brakes by stopping in 36.73m vs 38.29m, though the weight and braking force of both cars is too much for the tyres to handle effectively.

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Five years ago this wouldn’t have been close, but now it is. Very close.

Depending on your priorities you could make an argument either way, but the E63 S gets the nod as the superior driving machine. Would an air-sprung RS6 have changed the result? Probably not, but it would feel more cohesive.

Its size and weight prevent it from being a true driver’s delight, so why not (arguably) pay a slight dynamic penalty for a plusher ride and luxuriate in a phenomenally fast, all-weather family weapon?

Mercedes has a done a very considered job with this E63 S facelift. Its low-speed refinement and some of the ergonomics are still questionable, but its improved ride and benchmark safety systems make it a fine luxury sedan, while retaining its ability to tear your head off. AMG has not only moved in on Audi’s territory, but given it a hip-and-shoulder for good measure.

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The Strip

Lights, cameras, traction!

Heathcote Dragway, dry.
Driver: Scott Newman
Official timing Partner www.vboxaustralia.com.au

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The Specs

Twin-turbo V8 brutes