Audi RS6 vs BMW 850I

What's the difference?

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.

Does the world really need a car as outrageously loud, over-the-top, exclusive and stupidly fast as BMW’s new 8 Series? Obviously not, but BMW clearly felt that its range, and its customers, could do with something like this. On paper, and even from the kerb, it seems a strange beast - luxurious and yet lightning quick - but from the driver’s seat it just instantly makes sense. And makes you smile. Scarily, there’s an even faster 8 Series Competition version to come…

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.

In terms of improving on the car it’s replacing, the new 8 Series pretty much smacks it out of the park. Time has not been kind to vehicles fitted with pop-up headlights and the previous 8 Series, which roamed the planet in limited numbers from 1989 to 1999, with now-unimaginable V12 engines, seems a strange-looking beast, with its tiny little kidney grille almost hiding beneath a BMW badge.

The new M850i is a simply stunning looking beast, particularly in Coupe form (the Convertible is not ugly, but it just doesn’t look as complete). Extremely wide and menacingly low, it seems to loom over whatever patch of ground its parked on, giving off an air of magnificent malevolence.

It looks fantastic when followed from behind, but it’s the front view - featuring the thinnest headlight design ever seen on a BMW for a sleek, Iron Man-like face - that really grabs your attention.

Proportion, poise and big old 20-inch wheels give it plenty of presence, while the way the glasshouse tucks in at the rear only magnifies its powerful hips.

BMW has also thrown plenty of design flair at the interior, where you’ll find the unusual yet fabulous-feeling glass gear lever (there’s more of this sparkly, cut-crystal-like stuff on the volume knob, Start button and iDrive controller).

Not only does it feel truly unique and expensive in your hand, but it has an 8 buried beneath it, which shifts and shimmers as you try and see it through the many angles of the glass.

Elsewhere, the cabin is swathed in merino leather and feels undeniably classy, with a touch of modernity via its big screen, but it’s still not quite as beautiful as the cockpit you’d find in an Audi of a similar price. Close, but not quite.

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.

At the very least, you’d have to say the 8 Series is fit for purpose. The seats are hugely comfortable for long journeys, so that’s practical, there’s a handy tray for your phone, where it will be wirelessly charged, and there are two cupholders in front of that, and storage for bottles in the doors.

No human larger than primary school age will ever sit in the back, so there’s not a lot going on back there.

In terms of boot space, it’s reasonably capacious at 420 litres, or 350 litres for the Convertible.

It can be hard to use the word “value” when talking about a car that costs north of $270,000, and keep in mind that this 8 Series is thus even more expensive than a Porsche 911. And a car has to be very good indeed to be worth more than one of those.

We would respectfully suggest that this BMW is pitched a little high in price terms. 

Staggeringly, while the standard equipment list is lengthy and the inclusions are high end, you can still spend even more on options, and fairly easily push the price past $300,000 - Pure Metal Silver pain, for example, will set you back $10,400, while a pack of external carbon bits will hit you for another $7500, or $6,600 for the Convertible.

Standard equipment includes, deep breath, 20-inch M-branded light-alloy wheels, a tyre-pressure indicator, M Sport Brakes, M Sport Differential, Adaptive M Suspension Professional with Integral Active Steering, Active anti-roll stabilisation, Comfort Access including a kick-open tailgate, wireless phone charging, Soft Close Doors, BMW Crafted Clarity Glass Application, Driving Assistant Professional, Parking Assistant Plus, including 3D View and Reverse Assistant, Laserlights, a 12.3-inch digital instrument cluster and a 10.25-inch Control Display, metallics, paint, merino leather upholstery, heated steering wheel and arm rests, and seats, a 16-speaker harmon.kardon sound system, a Head-Up Display and the hugely pointless Gesture Control. 

The Convertible model also gets an Air Collar, to keep your neck warm when the roof is down.

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.

Truly, there is one impressive engine sitting under that big, hulking bonnet. The M-fettled 4.4-litre V8 has two turbochargers located inside the V of the block for “immediacy of response”, and they certainly deliver that.

Peak power of 390kW is delivered between 5500rpm and 6000rpm while its hefty 750Nm of torque is on song, for effortless overtaking, from 1800rpm all the way to 4600rpm.

Looking at those rev figures it’s clear to see that you are initially launched by a huge wave of torque and then, while you’re still drawing breath, the power really kicks in. 

All that grunt equates to 0 to 100km/h in just 3.7 seconds, which is very fast indeed, and you also get to enjoy a growly, guttural soundtrack, thanks to the standard Sport Exhaust.

The Convertible has the same engine with the same figures, but it’s slightly heavier and thus takes 3.9 seconds to hit the tonne. Which is still stupidly fast for this much car.

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.

Good luck ever matching these figures, with all that V8 temptation beneath your right foot, but the claimed number, at least, is 10.4 litres per 100km for the Coupe and 10.6 for the Convertible. During our launch drive we would have been absolutely nowhere near those figures.

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.

There is a sizeable distance between driving a small, lithe sports car that can sprint from 0 to 100km/h in a scorching 3.7 seconds, and then piloting something that feels as large, and louche, as a cruise ship that can do the same thing.

Accelerating in the M850i is an experience that can only be described as hilarious. There’s just so much mass attempting to move so quickly that it defies belief. The way the nose rears into the air, and the rear end seems to dip towards the ground, brings to mind a bucking bronco, although a feisty polo pony would probably be more appropriate.

It’s easy to see why this car is all-wheel drive rather than the traditional BMW rear-driven layout, because there’s just no way you could get all that grunt to the ground with two wheels, or not without some serious power oversteer issues.

For a car that weighs more than 1.8 tonnes, the 8 Series is surprisingly fluid and involving on winding stretches of road. It feels hunkered down and hammered into the road, which is less of a surprise, but the steering is so perfectly weighted and the power delivery so well calibrated that it really encourages you to push on, and rewards you sense of adventure with smile-widening pace.

It’s quite something to suggest of a car that costs a quarter of a million dollars, but the M850i actually exceeds your expectations in terms of driving joy. On paper, it looks like a straight-line bully, or merely a very grand grand tourer, and it does eat up the miles on a freeway with class and ease, but when you want to point it at a mountain pass, it excels there as well.

We drove the new 8 Series back to back with BMW’s also-new Z4, and what really stood out was not just the gulf in power and poise, but the huge difference in the ride/handling balance.

The M850i really can soak up the worst our roads can throw at it with aplomb, while still making you feel connected to the ground beneath you, and inspiring confidence, and its abilities really did make the Z4 feel very brittle and hard indeed.

To be fair, we didn’t get to throw this big luxo-barge at any sections of really sharp S-bends, or 35km/h corners, and no doubt it would be challenge for it to change direction quickly, but through fast sweepers it really does excel.

And as far as its grand-touring design brief, it absolutely nails it.

There’s no ANCAP rating to go on for this car, and nor is there anything similar out of Europe to give us guidance, but you do get eight airbags - front, full-length sides and head protection on the sides and in headliner, plus knee airbags for the front seats.

The 8 Series also gets Driving Assistant Plus as standard, which includes Active Cruise with full Stop&Go function, which BMW considers to be “full AEB”, meaning it will bring the car to a standstill, automatically, when required.

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?

BMW is sticking with its not-very-industry-leading three-year, unlimited-kilometre warranty, and says its customers are happy with that, rather than the five- or seven-year warranties some other companies offer. When you’re paying this much for a car, it seems a trifle mean, frankly.

Like all modern BMWs, the servicing requirements for your M850i are controlled by the Condition Based Servicing (CBS) system, which means that “advanced algorithms monitor and calculate the conditions in which a vehicle is used, including mileage, time elapsed since its last service, fuel consumption and how a vehicle is driven”. 

That information allows the car to decide for itself when an annual vehicle inspection or oil service is due.

BMW offers two fixed-price servicing plans, under its BMW Service Inclusive (BSI), which is available in two packages: Basic - $2,290 for five years/80,000km or $5,170 for Plus.