Audi S6 vs Audi RS4

What's the difference?

We adore the new S6 sedan. It looks great, feels comfortable and goes like stink all at the same time. What’s not to like?

It also helps that it is relatively good value, safe and practical by large-sedan standards, so it’s a bit of a no-brainer.

But will buyers be quick to dismiss the new S6 sedan because it’s not a more practical SUV? Time will tell, but we hope not.

Does the new Audi S6 sedan represent the best mix of executive style and boy-racer performance? Tell us what you think in the comments below.

What a way to send off this generation of Audi RS4 and RS5. The extra focus courtesy of those trick coil overs and drama from the exhaust plus the sharper gear changes deliver the best Audi has done with these RS products. 

There are some compromises, with the suspension favouring outright control over low-speed comfort. It’s also true that the current BMW’s M3 and M4 are more impressive, but when the products are nearly seven years fresher than Audi’s, what do you expect? 

Plus, those looking for a more restrained and polite fast executive sedan (or wagon) will gel with the Audi’s sophistication. There aren’t many of these Competition Plus RS4 and RS5s coming to Australia and they are impressive visually and from behind the wheel. It’s a fitting way to send off the current generations.

Note: CarsGuide attended this event as a guest of the manufacturer, with accommodation and meals provided.

To these eyes, the new S6 sedan is very attractive, albeit not outlandish, in keeping with its executive focus.

Up front, the subtly aggressive S body kit immediately comes into frame, with the bumper sporting sinister-looking side air intakes.

And, of course, there’s Audi’s signature Singleframe, which is not only large and in charge, but also finished in gloss-black, like many of the S6 sedan’s exterior design elements.

Below the heavily creased bonnet, the HD Matrix LED headlights look both angry and sophisticated, with their integrated LED daytime running lights (DRLs) providing a crisp signature.

Around the side, the S6 sedan goes about its business quietly, but its blistered wheelarches do add some bulk and help to accentuate its strong shoulder line.

And then there are the thick skirts and 21-inch alloy wheels (with a space-saver spare), which have a sporty twin five-spoke design. It’s all very classy.

Speaking of which, the rear end is arguably the S6 sedan’s best angle thanks to its wicked LED tail-lights, which have a segmented signature.

The chunky bumper below incorporates a diffuser element that houses the quad exhaust tailpipes, while a blink-and-you’ll-miss-it bootlid spoiler rounds out the look.

Inside, the S6 sedan is a technological tour de force, with 10.1- and 8.6-inch touchscreens dominating its centre stack. The former is responsible for most of Audi’s latest multimedia system’s functions, while the latter takes care of the climate controls.

This set-up works pretty well, although a few too many taps are required for certain functions, and then there’s the issue of the glass display coverings, which are absolute fingerprint magnets alongside the gloss-black accents used throughout.

That said, the 12.3-inch digital instrument cluster and windshield-projected head-up display on hand are brilliant. In fact, they set the standard for the entire industry thanks to their design and breadth of functionality.

The S6 sedan does, of course, feel a little bit more special than the regular A6 inside, with the obvious additions being the front sports seats, which are covered in supple Valcona leather alongside the armrests. They even have diamond-stitched inserts.

Then there’s the obligatory flat-bottom steering wheel (with paddle-shifters), which is trimmed in Nappa leather alongside the gear selector, upper dashboard, door shoulders and knee rests. Indeed, hard plastics are hard to find here.

Meanwhile, a black headliner adds to the sportiness alongside the black Alcantara door inserts, but the cabin is otherwise a familiar (read: classy) affair.

The RS4 Avant’s 'Progressive Red' metallic helps the black milled 20-inch alloy wheels pop. Its stance is hugely purposeful with wheels tucked right up in the blistered arches courtesy of the lowered ride height — it's how the Avant would have looked in a design sketch.

The visual bulk of the long-roofed RS4 gives it the sort of proportions motoring journalists love to wax lyrical about, even if plenty of buyers still prefer coupes or lifted SUVs. 

The RS5's more flowing, elegant lines match well with the Navarra Blue paint work, silver-accented wheels and conventional leather-appointed seats within. 

Both cars have effectively identical front cabins reflecting Audi’s classy and sleek design language. The integration of technology is pretty good and the RS4’s additional red styling pack really makes it feel sporty within.

Measuring 4954mm long, 1886mm wide and 1446mm tall, the new S6 sedan is a large sedan in every sense of the term, which is mostly good news when it comes to practicality.

Cargo capacity is decent, at 520L, but can be increased to an undisclosed amount with the 40/20/40 split-fold rear bench stowed.

Speaking of the boot, there are four tie-down points and a cargo net to help secure loose loads, while a bag hook and a side storage net are also on hand, alongside a 12V power outlet. Bulkier items will, however, be confronted by a decent load lip.

In-cabin storage options are numerous, but not all are effective. The glovebox is well-sized, while the driver-side cubby is surprisingly large, but the central bin is shallow, mostly taken up by the wireless smartphone charger, two USB-A ports and the SD and SIM card readers.

A pair of cupholders is located in the centre console, with a 12V power outlet found in between, while the front door bins can accommodate one regular bottle each, just like their rear counterparts.

In the second row, there’s a fold-down armrest with two more cupholders as well as a shallow storage tray, while cargo nets are affixed to the front seat backrests.

The rear bench is pretty comfortable, with four inches of legroom available behind my 184cm driving position alongside decent toe-room. Headroom is also good, with about two inches on offer.

That said, three adults sitting abreast won’t enjoy the experience, due to the large transmission tunnel, which makes for limited footwell space. At least they’ll have access to a couple of USB-A ports and a 12V power outlet, below the central air vents.

For reference, child seats can be fitted to the outboard seats via top-tether and ISOFIX anchorage points.

The RS4's cabin is excellent, with a good mix of physical buttons and responsive touchscreens for control. There’s enough storage space for this kind of vehicle, with good door bins and well-sized cupholders in the centre as well as USB-C and -A charge points. 

Audi’s multimedia system is friendly though the large touch targets and dark background aren’t as crisp as those fitted to the latest rivals. The screen isn't as big, either, measuring 10.1 inches for the multimedia item. The RS4 supports wireless Apple CarPlay and Android Auto.

That said, Audi’s 12.3-inch digital driver’s display with bright and poppy mapping software and generous customisation remains right at the head of the pack. 

There is a panel of switches below the touchscreen for climate control, physical selection of the five-or-so drive modes and a collection of helpful buttons on the perfectly-shaped and sized leather-appointed steering wheel.

It lacks F1 or DTM wow-factor compared to the C63 and M3 with their easy-access driver mode buttons and toggles on the steering wheel but the RS4's restrained looks will resonate with those that prefer a bit more elegance inside. 

Neither the RS4 nor RS5's back seats are designed for those over about 175cm. The RS4’s roof is a little higher so it is good enough for most adults but the RS5’s sloping profile compromises things. It has two individual buckets compared to the RS4’s three-wide bench. 

Rear seat passengers get air vents, an individual climate zone, bottle holders in the doors, USB charge points and ISOFIX attachments for the outboard seats, with matching top tethers in the seat backs.

The Audi RS4’s boot is a generous 505L with under floor storage and a netted area on the driver’s side. Folding the 40/20/40 split-fold bench increases space to 1495L. That said, the RS5’s 465L is still very good, though it is not quite as practical in the real world. 

Being fitted with roof rails makes for sleek integration of roof racks for the RS4 to slip roof pods, bike racks or whatever else you might choose to take on a trip away.

You'd expect the RS5 to be more popular given how uncool wagons are these days but Audi's whole thing is wagons — or Avants, for the initiated — so it makes sense that the RS4 Avant outsells the RS5 Sportback about two-to-one.

For the RS4 Avant’s basic asking price of $165,015, before on-road costs, you get luxury features such as LED headlights, an RS design package, Nappa leather upholstery, power-adjust seats, a Bang & Olufsen 19-speaker sound system and metallic paint on top of the significant changes to the RS4’s chassis and zingy 331kW V6. 

The RS5 is a little dearer, reflecting the addition of Matrix LED headlights that aren’t available on the wagon.

But we have the 'Competition Plus Pack', which is a $13,990 indulgence that swaps adaptive dampers for Audi’s 'RS Sport Suspension' coil over package with manual rebound and compression adjustment and height adjustment.

The cars sit 10mm lower than a normal RS4 but you can go to a dealer to move the ride height up or down from there. 

That’s not it, though. You also get a louder exhaust system with matte black pipes, fixed-ratio steering system, a retuned eight-speed automatic with more aggressive shifts, different rear differential programming, black exterior badging, 2.0kg lighter 20-inch Audi Sport wheels (in silver or black), special LED entrance lights and your speed limiter raised to 290km/h.

The 'Navarra Blue' RS5 pictured is a ‘basic’ Competition Plus. You can go further, as done with the RS4 Avant with its manual-adjust bucket seats ($1300), 'Interior Design Pack' in red ($3400), matte carbon exterior pack ($6300) and carbon trim, bringing its total cost to $191,405, before on-road costs. 

That makes the RS4 and RS5 the most affordable in their competitor set, below a BMW M3 Competition xDrive Touring ($183,500) and Mercedes-AMG C63 S E Performance hybrid, which is $187,900, before on-road costs.

The new S6 sedan is powered by a hard-hitting 2.9-litre twin-turbo V6 petrol engine that produces a strong 331kW of power from 5700-6700rpm and a punchy 600Nm of torque from 1900-5000rpm.

Compared to its aforementioned predecessor, power is unchanged, while torque has increased by 50Nm.

This unit is mated to a 48V mild-hybrid system that includes a trick Electric-Powered Compressor (EPC), which helps to reduce its turbo lag.

A reliable eight-speed torque-converter automatic transmission is responsible for swapping gears, while drive is sent to all four wheels via Audi’s rear-biased quattro system.

This combination helps it sprint from a standstill to 100km/h in an impressive 4.5 seconds, while its top speed is electronically limited to 250km/h.

Audi’s 2.9-litre twin-turbo petrol V6 has seen plenty of use across performance products from Audi and Porsche, including the Macan S and Audi S6. 

In the RS4 and RS5 Competition Plus, it develops the same 331kW (at 5700-6700rpm) and 600Nm (at 1900-5000rpm) as the regular car. This makes it an extremely flexible engine that delivers predictable punch anywhere in the power band.

That said, it lacks the explosive character of BMW’s twin-turbo inline six — the figures are only 15kW and 50Nm higher on paper yet the M3’s response is that much more ferocious. 

Audi’s RS division has tried to capture a bit more emotion, retuning the eight-speed torque converter automatic transmission for crisper shifts. This also benefits the RS4’s 0-100km/h sprint time, which falls two tenths to 3.9 seconds in Competition Plus guise. 

The V6 breathes a little easier, too, with a different exhaust. Audi says the extra sound is down to 8.0kg less sound deadening in the car.

There’s more resonance at idle that does feel tiring sitting in traffic idling but the trade-off is a brawny mid-range baritone that develops into a shrill bark approaching the redline.

The new S6 sedan’s fuel consumption on the combined-cycle test (ADR 81/02) is 8.4 litres per 100 kilometres, while claimed carbon dioxide emissions are 197 grams per kilometre. Both figures are pretty keen given the level of performance on offer.

Audi says the aforementioned 48V mild-hybrid system reduces fuel consumption by 0.4L/100km thanks to its coasting ability, which sees the engine turn off for up to 40 seconds between 55km/h and 160km/h. It also engages idle-stop from 22km/h.

In our real-world testing, we averaged 14.4L/100km over 100km of driving skewed towards country roads over city traffic, with limited highway time. It’s worth noting that my spirited driving inflated this result. That said, while its fuel consumption is not as bad as it appears, this is still a thirsty sedan.

For reference, the S6 sedan’s 73L fuel tank takes 98RON petrol at minimum.

The Audi RS4 wagon is rated to use 9.5L/100km in ADR combined cycle (urban/extra-urban) consumption testing while the slipperier RS5 returns 9.4L/100km in the same test. 

We weren’t able to run accurate or particularly relevant fuel figures on the event but the trip computers showed around 12L/100km in both RS4 and RS5. 

While these numbers are high compared to your average passenger car, the Audi is more efficient than BMW's rivals, and gets remarkably close to the hybrid C63 in the real world.

The fuel tank is quite small for this kind of vehicle at 58 litres. That limits the RS4’s theoretical driving range to 611km. 

Unsurprisingly, the Audi RS4 and RS5 require 98 RON premium unleaded petrol. 

The S6 sedan has no right being this good in a straight line and around corners…

Much of its success is owed to the 2.9-litre twin-turbo V6, which is now one of my favourite engines being built today. Simply put, it absolutely hammers.

Punch the accelerator from a standing start and it doesn’t take long for 600Nm to be on tap all the way through, and just a little bit beyond, the mid-range.

Occupants are firmly pressed into their seats as the S6 sedan sprints towards the horizon with vigour. Soon enough, 331kW arrives and hangs around until just prior to the redline.

Needless to say, this acceleration is addictive, and the EPC deserves some of the credit, as it effectively mitigates any dreaded turbo lag and ensures the engine is always seemingly on boost.

But we also need to acknowledge the eight-speed torque-converter automatic, which is a real beauty. Gear changes are nice and smooth, which is great, but what’s even better is their relative quickness – dual-clutch transmissions be damned!

Of course, extra performance can be extracted by switching between the engine and transmissions’ settings but, rest assured, they both stand up, no matter what.

However, we’d suggest spending time in the former’s most aggressive setting, as it unleashes the sports exhaust system, which sounds unreal.

Upshift with intent and you’re met with a booming ‘brap’. Downshifts and the overrun will even gift you a series of pops. In fact, the S6 sedan soundtrack sounds strangely similar to that of the five-cylinder RS3, and we have absolutely no problem with that.

Better yet, the S6 sedan has an appetite for corners, with its neutral handling a standout, partly thanks to its hard-working rear-biased quattro all-wheel-drive system, which works in tandem with all the other electronics to ensure there is plenty of grip at any given time.

This controlled driving pleasure is enhanced by the electric power steering on hand, which has a variable ratio. At low speed, it’s nice and light, but those after more heft can always switch to another one of its settings, which become progressively heavier… arguably too heavy.

Feedback through the wheel is also good, while the steering itself is pretty direct, lending itself to sporty driving, which, of course, is half of the S6 sedan’s mantra.

Coming into corners, braking performance is solid, thanks to the massive 400mm front and 350mm rear discs with red callipers, so the driver is brimming with confidence at every turn, even though there’s an unladen weight (with 75kg driver and luggage) of 1985kg to manage.

But let’s not forget the S6 is an executive sedan, so it has to ride like one. Thankfully, it does. The independent five-link suspension has air springs and adaptive dampers, which serve up comfort in spades, especially at high speed.

Its firm tune does come into frame when travelling on unsealed or uneven roads, with this exacerbated by the large 21-inch alloy wheels, which have a penchant for catching sharp edges.

The time allocated to driving the RS4 Avant Competition Plus was fairly limited and we were sadly unable to sample how the highly adjustable coil over suspension performed where it makes most sense — on the racetrack. 

Still, winding country roads between Sydney and the Southern Highlands served up some challenges, demonstrating how the Competition Plus pack changes the character of the RS4 and RS5. 

The only real negative is comfort, specifically over those horrible plastic speed bumps that litter shopping centre car parks. With adaptive dampers, carmakers can set programs for these kinds of obstacles to soften and stiffen the clever shocks at just the right time. Not so the Competition Plus pack cars, which ride these bumps harshly.

That about does it, though, and everything thing else is a net benefit. The steering system addresses some criticism of the earlier RS4s. Further than a retune, the Competition Plus gets a new rack, that is non-progressive with a fixed ratio of 15:1 (instead of 13.3:1) and 2.4 turns lock-to-lock. The reactions to each input feel a hint more faithful. 

When above 40km/h the coil overs come into their own. Even though the RS4 rides firmly it doesn’t constantly jiggle over small bumps. Over sharp-edged hits, the suspension rounds the hits off so, while you feel them, there’s a sense of control and sophistication. 

Having speed limits to contend with means it is essentially impossible to find the limits of grip of the 275/30R20 Continental SportContact 6 tyres on the road and there isn’t much body roll, either.

The RS4 is still rewarding, though, getting up on its toes just enough through a series of bends to feel engaging. It gives an impression of being quite light and at 1820kg it is now considered featherweight next to rivals.

The RS4's Quattro all-wheel drive system favours the rear wheels when driving normally (60 per cent rear) and can send up to 85 per cent of the drive to the back axle. 

The tweaked electronically-controlled rear limited-slip differential amplifies the throttle steer-ability of the RS4, giving you the confidence to squeeze the gas on exit. 

It helps that the Competition Plus bucket seats are a little thinner and set closer to the floor giving you more feedback. This is the key differentiator between the RS4 and RS5 we drove — the buckets make the car feel alive. 

Strong brakes are made up of 375mm front rotors clamped by six-piston calipers. Optional carbon ceramic brakes with larger 400mm front rotors help save 6.5kg and, if you plan to use the RS4 on track, are a smart buy along with a set of Pirelli P Zero Corsa semi slick tyres ($850). 

Really, though, neither the RS4 nor RS5 are the perfect car for the track. They are plenty capable and fast on the road with just enough fun, reward and character thrown in to keep you coming back for more.

The Audi A4 range was rated a maximum five stars in ANCAP safety testing in 2021, with the rating now considered expired. The stamp also only applied to four-cylinder models — so not the RS4 we drove. 

It has lots of safety equipment, including eight airbags (dual frontal, side chest, front and rear side head curtains), autonomous emergency braking (AEB) functional up to 250km/h with pedestrian detection, front and rear cross-traffic alert, lane-keep assist, blind-spot monitoring, safe exist warning and tyre pressure monitoring.

Adaptive cruise control with lane-trace assist makes it an easy car to use on the motorway. The systems are well integrated and easy to switch on and off as you like. 

The S6 sedan comes with Audi Australia’s three-year/unlimited-kilometre warranty, which falls short of the premium market’s relatively new five-year standard that was set by Genesis and followed by Mercedes-Benz.

Three years of roadside assistance is also bundled in, although this term can be extended up to nine years if the vehicle is serviced at an authorised dealership, which is great.

Speaking of which, service intervals are every 12 months or 15,000km, whichever comes first. Capped-price servicing plans are available, costing $2350 for three years/45,000km or $4110 for five years/75,000km. They’re pricey, but you weren’t expecting the opposite.

Audi covers the RS4 and RS5 with a five-year/unlimited kilometre warranty which is now the expected norm across the premium part of the market. 

A five-year service plan can be pre-purchased, costing $3630 for both models with maintenance due annually or every 15,000km. 

After the five-year warranty period, owners can choose to extend the service packaging and warranty for two extra years at a cost of $4260. This can be done twice, extending the warranty up to nine years.