Audi S4 vs Audi RS6

What's the difference?

The S4 and S5 range continues to represent a great formula for performance you can live with every day. They're arguably the sweetest balance Audi produces, actually. All come fantastically equipped, with cabins that feel truly special, and we’re lucky they can be had in a choice of five bodystyles.  

To me at least, the RS6 is pretty much the ultimate fast and practical car. One which is just as comfortable plodding around town as it is tearing it up on the track. Keep in mind, too, this may be one of your last chances to have a car which looks like this, equipped with a V8 engine. So, have I convinced you? Would you consider one of these over a performance SUV? Tell us what you think in the comments below.

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

The S4 sedan and Avant have scored the bulk of design updates, with all new and recontoured side panels including the sedan’s C-pillar matching what was applied to the A4 earlier this year. 

This is paired with new front and rear facias and lighting for a subtle but extensive rework of the fifth-generation S4’s conservative look. 

The S5 Sportback, Coupe and Cabriolet get S5-specific new lighting and facias, but no sheetmetal changes. As before, the Coupe and Cabriolet ride on a 60mm shorter wheelbase than the Sportback, sedan and Avant.

The S5s also get Matrix LED headlights as standard which do a neat animated sequence when you unlock the car. 

Other visual hallmarks include new S4-specific 19-inch wheels, with S5 stepping up to its own unique 20-inch wheel. The six-piston front brake calipers are appropriately painted red, and there’s S-specific adaptive dampers under there too. All variants aside from the Cabriolet get a lip spoiler on the rear.

On the inside, there’s a new centre console and bigger 10.1-inch multimedia screen, while the Audi Virtual Cockpit driver instrument display now offers a hockey stick-style rev counter in additional to traditional dial layouts.

At a distance the RS6 is just an unassuming station wagon, but the closer you get, the more apparent it becomes how mean it is. It’s wide, it’s chiselled, it’s not just good looking, it’s iconically Audi.

The stance is so wide, its ride height so low, and its wheels are so massive that any keen eye will be able to spot where the difference is between this and any old family hauler.

Wagons may not be trendy, but there’s something undeniably cool about having the hauling capacity of an SUV at the ride height of a sedan.

Of course, if you want to look even more svelte and don’t need the boot space, the RS7 is always lurking around at a slight price premium.

Inside, the RS6 has all the modern amenities of the Audi range. Expect the usual sharp screens, lovely sports seats, and a tasteful application of textures throughout.

There’s a blend of carbon-look finishes, chrome, leather and gloss black. Perhaps a little too much gloss black to keep clean, but the aesthetic is suitably upmarket. 

You can go to town on customisation, and the car we primarily tested had stitching and colour in the carbon patterns to match its 'Ascari Blue' exterior, but you can pick whatever shade or combination of colours your budget allows.

Audi’s software is pretty good these days, with an attractive theme and fast hardware to back it, and the brand’s ‘Virtual Cockpit’ is still one of the most aesthetically pleasing and customisable digital instrument systems on the market, despite being one of the first.

The biggest practicality change among the five S4 and S5 variants is their upgrade to the latest version of Audi’s MMI multimedia system, which steps up to a 10.1-inch touchscreen and drops the scroll wheel from the centre console.

It also boasts ten times the computing power of the version it replaces and uses this and an on-board sim card to access Google Earth maps for navigation and Audi Connect Plus that offers driver information such as fuel prices and parking information as well as point of interest search and weather information, plus the ability to make emergency calls and seek roadside assistance.

There’s also a wireless phone charger, but using Apple CarPlay will still require a cord as per Android Auto.

I only drove the S4 Avant and S5 Sportback at their media launch, which are clearly the most practical of the five, but from our experience with the previous versions, each looks after its occupants well in terms of space and storage. Back seat accommodation is clearly not a priority in the Coupe and Cabriolet, but there’s three other variants if that’s what you’re looking for. 

The Cabriolet can open its automatic folding soft top within 15 seconds, at speeds of up to 50 km/h.

Okay, I promised a car with the practicality of an equivalent SUV, but it’s not quite there. The trade-off is still worth it, I promise, but there are a few areas where the RS6 isn’t as practical as you think it’s going to be, particularly for front occupants.

Yes, it’s a big wide car, with large but supportive seats and plenty of headroom, but the issue for those travelling in the front two seats is the surprisingly limited amount of storage.

Yes, there are two bottle holders in the centre console with a folding tray lid to hide them away, but they aren’t huge. Bigger bottles would have to go in the door bins, but even then they’re a bit height-constrained.

There’s a decent glove box on the passenger side, but even the centre console box is very shallow, with more than half of it taken up by a wireless phone charger.

The touch panel for the climate unit looks impressive but still can’t match having physical dials. It has clicky haptic feedback to your individual presses, and all the functions are permanently accessible instead of hidden in sub-menus, so if you’re going to make climate a touch-based interface, it doesn’t get much better than this.

Where the RS6 shines is in the back seat. Despite those big bucket front seats, I had heaps of room behind my own seating position (at 182cm tall), with lots of headroom and sufficient width in the cabin to spread out.

You sink into the rear seats, which are heavily contoured so riding in the back is a pretty good experience even on the track.

Rear passengers get four adjustable air vents in both the B pillars and in the centre, as well as their own touch panel for the rear climate zone.

USB power outlets are also available, and there are netted pockets on the front of both back seats, with a further two bottle holders in the drop-down armrest.

The centre seat is probably only good for kids, because there’s a very tall raise in the centre required for the driveshaft, eating all the legroom.

The boot is fairly large at 548 litres which is in mid-size SUV territory, although I will admit some performance SUV rivals offer closer to 600L.

Space expands to 1658L with the second row folded flat.

Let’s start with the bad news. Most people can’t afford one of these. The RS6, in all of its muscular glory, is more expensive than ever before. Now wearing a before-on-roads price-tag of $241,500, it’s hardly your average mum and dad family hauler. But then, there’s nothing average about the RS6.

It’s so well regarded amongst enthusiasts for multiple reasons. It’s the biggest meanest wagon you can buy, and somehow Audi has managed to make this version more powerful and even faster than before.

In fact, it’s one of the few normal looking combustion cars out there which can still hold a candle to many electric cars, with its whomping V8 helping it warp from 0 to 100km/h in just 3.4 seconds.

More on those performance specs later. If you’re wondering what else you get for your near-quarter-of-a-mill it’s pretty much every spec item Audi currently offers.

There are now lighter 22-inch alloy wheels, adaptive air suspension, a high-performance braking system, an RS-specific exhaust system, matrix LED headlights with adaptive high beams, a 10.1-inch multimedia touchscreen with navigation and wireless phone mirroring and one of the best digital instrument clusters on the market.

It also features Valcona leather interior trim, sporty bucket seats with perforated trim, honeycomb stitching, as well as ventilation and heating, additional cabin trim in synthetic suede (comprised of 45 per cent recycled fibres), ambient interior lighting and a panoramic sunroof.

It’s a lot of stuff, but one thing you get a little less of is sound insulation. Audi has chosen to remove some of it this time around so you can hear the V8 better from behind the wheel.

Audi has taken an ‘if it ain’t broke’ approach with the mechanicals, with all S4 and S5 models unchanged with this update. So the centrepiece continues to be the single-turbocharged 3.0-litre V6 that produces 260kW and 500Nm, with the latter available from a broad 1370-4500rpm.

The rest of the drivetrain is also unchanged, with the venerable but excellent ZF eight-speed torque converter auto paired with the Quattro all-wheel drive system that can send up to 85 per cent of drive to the rear wheels. 

The RS6 is still packing eight cylinders in 2023, producing a massive 463kW/850Nm, somehow an increase (+22kW/50Nm) over the previous iteration.

Audi’s signature ‘Quattro’ all-wheel drive system is present alongside a limited-slip differential and four-wheel steering.

Air suspension and performance brakes and exhaust also feature, alongside an aggressive Continental SportContact 7 tyre package.

The 0-100km/h sprint time is now just 3.4 seconds, allowing you to show up even some electric cars, and the RS6 features 48-volt mild hybrid technology with a cylinder-on-demand system which can shut half the block down for more efficient coasting.

The transmission is an eight-speed torque converter unit which is smooth and effortless.

Official combined fuel figures range from 8.6L1/00km for the S4 sedan to 8.8L/100km for the Avant, Coupe and Sportback, while the heavier Cabriolet steps up to 9.1L/100km. 

All are pretty good considering their performance potential and the size of these cars, plus the fact that they only require 95 RON Premium Unleaded fuel.

All have a 58-litre fuel tank, which should enable a range of at least 637km between fills based on the Cabriolet’s figure.

Officially, the RS6 and its eight cylinders drink a combined 11.8L/100km, although even with its fancy hybrid system and cylinder deactivation, my time with the car saw 15.0L/100km. The RS6 has a 72-litre fuel tank and takes only the finest 98RON unleaded fuel.

The S4 and S5 range were already an excellent balance between everyday comfort and a genuine sporting edge, and nothing has changed with this update.

I spent time behind the wheel of the S4 Avant and S5 Sportback at their media launch, and both managed to deliver the proper Audi luxury experience over some pretty rough rural roads, while always feeling a bit more sporting than a regular A4 or A5. That’s with the Drive Select left in the default mode, but you can shift that sporting personality up a few notches (while scaling back the comfort), by selecting Dynamic mode. 

My preferred means of adjusting their personality is by simply tugging the transmission selector back to activate S mode, which livens up the engine and transmission without stiffening up the suspension. 

Across the five S4 and S5 bodystyles, there is some variance in performance potential, with the S4 sedan and S5 Coupe topping the performance chart with 0-100km/h boasts of 4.7s, with the S5 Sportback trailing them by 0.1s, the S4 Avant by a further 0.1s and the Cabriolet managing a still-fast 5.1s claim.

Another area I consider the S4 and S5s to get just right is their exhaust note. It is adaptive, but there’s nothing synthetic about it, and the generally muted and distinctly V6 burble is always there to remind you that you’re aboard a proper performance model, but not in such a way that it will annoy you, or your neighbours. Polite performance, if you will.

As you might have guessed from its impressive engine and performance equipment, the RS6 is a certified weapon on road and track.

On the road you can expect a quiet, refined cabin, superbly balanced steering for low and high speeds and a gentle ride quality courtesy of the pricey air set-up.

It’s as noisy or as quiet as you want it to be, with the cylinder deactivation toning things down at low speeds, and the engine roaring to life under heavy acceleration, or when the 'Dynamic' drive mode is selected.

It can at times be alarming how much the RS6 leaps to life, as it feels so cushy in a city, its width and cabin giving the feel of a luxury car rather than a performance one.

Make no mistake, though, the RS6 is properly quick, and when you give it a kick, it’s the roaring, aggressive machine the spec sheet suggests.

The best place for this? The track, of course. The big V8 and the capability of the all-wheel drive system are truly best explored at velocities impossible to legally achieve on the road.

Once you get past the bark and snarl of this wagon’s eight-cylinders at full force, and the lightning-fast shifts of its eight-speed automatic, you’ll have a moment to appreciate the way it simply holds to the tarmac when you tilt it into the corners, providing a balance when loaded up which only air suspension can provide.

The steering is awesome, communicating the texture of the road nicely to the driver, and requiring just the right amount of force to keep the car pointing where it needs to go.

The grip level is astounding with the huge tyres and the four-wheel steer system lets this hefty wagon take corners at a tighter angle than your brain initially allows.

Thankfully, the four-wheel steer system isn’t weird, either. While it can have a strange effect on some cars, in the RS6 it only bends your mind slightly when you tip it into a hairpin. Otherwise it feels pretty normal.

When everything is warmed up, it can let its guard down slightly and allows the driver to eke out a slide at the rear here and there for extra fun-factor

Jeez. What a machine. I guess this is what a quarter of a million dollars buys. A car that can do it all. Take the kids to the school in comfort and tear it up on the track like few other passenger cars on the same day.

There’s a caveat, though. A small one which looks like it will turn into a big one for cars like this in the near future.

I had the opportunity to drive the RS e-tron GT around the same circuit and it was better. Much better.

It was faster, more accurate, more composed. It was so effortless, I didn’t realise exactly how much quicker than the RS6 it was until I drove them back-to-back.

It’s a good sign for the future, but also a reminder a V8 like this isn’t the performance pinnacle it once was.

Like its standard cabin equipment, the RS6 has had the entire catalogue thrown at it for active safety gear. Included is freeway-speed auto emergency braking with pedestrian, cyclist, and intersection detection, lane keep assist with lane departure warning, blind-spot monitoring with rear cross-traffic alert, an exit warning system, and adaptve cruise control with traffic jam assist.

Elsewhere the RS6 gets dual front, dual side, and head curtain airbags, with ISOFIX points on the outer two rear seats as well as three top-tethers across the rear row.

The RS6 is not safety rated by ANCAP, but the rest of the A6 range was awarded a maximum five stars in 2018. 

Audi continues to offer a three year, unlimited kilometre warranty, which is in line with BMW but lags behind the five years offered by Mercedes-Benz these days. This also contrasts with the five year norm among mainstream brands, which is punctuated by the seven year warranties of Kia and SsangYong.  

Service intervals are a convenient 12 months/15,000km though, and the same five year ‘Audi Genuine Care Service Plan’ offers capped price servicing for the same $2950 total over five years applies to all S4 and S5 variants. This is only marginally more than the plans offered for regular petrol A4 and A5 variants, so you’re not being stung for the thoroughbred versions.

Five years and unlimited kilometres is the warranty length, and Audi’s ownership program includes invites to events like the one we were able to experience for the launch of this car. A track-test of the RS6 and the RS e-tron GT.

If you own one, I recommend them, you’ll learn a thing or two about the car and possibly yourself while you’re at it.

Servicing is required once every 12 months or 15,000km, and a service pack covering the first five years or 75,000km can be purchased alongside the car at a cost of $4360.

It works out at $872 per year, which isn't economy car cheap, but with such a complex drivetrain, what did you expect?