Audi A8 vs BMW 840I

What's the difference?

The Audi A8 swims in a luxury car shark tank where those paying the big dollars expect top-shelf everything. It delivers a serene driving experience whether you’re in the front or the back, in a superbly engineered and executed luxury sedan package. Not perfect, but very, very impressive.

If you’re the sort of buyer who wants a car that signifies a lifestyle that is ‘large and in charge’, the BMW M850i Gran Coupe could be just the thing for you. It isn’t as showy as some of its competitors, and mightn’t reach the same levels of excitement as those cars either - but it is a convincing offering in its own right, and a beautiful piece of design at that. 

The A8 is close to 5.2 metres long, yet instantly recognisable as an Audi thanks mainly to its evenly weighted proportions, gently curved roofline and overall high-waisted design. Worth noting its drag coefficient (Cd) is an impressively slippery 0.25.

The characteristic look is accentuated by the brand’s signature, six-sided grille, in this instance highlighted by a matrix of high-relief chrome accents. And typically angular LED Matrix headlights sit either side.

Check out our video review for the carefully orchestrated animation they run through when the car is unlocked.

The car looks equally svelte and contemporary from the rear, with just the right amount of chrome lifting the tone and multi-spoke 20-inch rims filling the wheel arches nicely.

As you’d expect, the top-shelf look and feel continues inside with the seats trimmed in aniline leather, perforated on the front and outer rear positions, with genuine hide also covering the centre console, door rails and armrests, steering wheel and upper dashboard.

Fine grain ash wood inserts sit alongside brushed metal elements and a meticulous attention to detail is obvious… everywhere.

For example, the interior door handle design has been thoroughly thought through, requiring a simple underhand tap to open the door, rather than the more conventional, and ergonomically convoluted, ‘over the top’ movement.

Three sleek screens dial up the tech - a 10.1-inch multimedia interface at the top of the centre stack, an 8.6-inch display below it for heating and ventilation, and a 12.3-inch version of Audi’s ‘Virtual Cockpit’ in the instrument binnacle.

And the spacious rear is the epitome of cool, calm Teutonic form and function. You feel relaxed the moment you get in, and isn’t that the primary aim of a car like this?

This could be BMW’s most convincing design in years. I mean, the X5 is predictably handsome, the X3 was unexpectedly muscled, and the less said about the frumpy 1 Series and busy 3 Series (apart from the wagon… drool) the better.

To my untrained but enthusiastic eye, the 8 Series Coupe is a bit too rounded over its rear haunches, and the rear screen is just a little steep - to me, that lets its dimensions down a little. But this. This is gorgeous. 

I mean, you might have questions over the tail-light design, which is a theme across a few BMW models now. But there isn’t as much confrontation between horizontal and vertical graphics for this model as you’ll find one other big Bimmers, like the X7. 

The M850i model has BMW Laserlight headlights, which throw a sharp beam and look menacing in their signature, while the grille and bumper are strong. The stance of the car is prominent - there’s a long body, a long wheelbase, and a long body in general. The standard wheel package consists of 20-inch rims, and they don’t look disarmingly large.

As our images show, there’s a lot to talk about when it comes interior design and finishes, but the cabin doesn’t quite benefit quite as mochas you might think it would from all that real estate. I mean, with dimensions of 5074mm long (on a 3023mm wheelbase), 1932mm wide and 1402mm tall, this is a squat, yet substantial vehicle. It’s just more cramped than you’d think inside.

Space is luxury, be it a large house, a first class seat or a spacious car, and at nearly 5.2 metres long with a close to 3.0m wheelbase the Audi A8 measures up. 

Even before you get in, the doors have an amazing sense of solidity and quality. It’s like opening and closing a bank vault… if that huge circular door had a power-assisted soft-close function. 

There’s copious amounts of space for the driver and front passenger with lots of storage including a lidded box between the front seats, complete with a two-piece longitudinally split top design, so you can sneak your half’s open without displacing your neighbour’s elbow.

The door bins are decent but there isn’t a specific cut-out for bottles, so it’s more a case of laying them down than standing them up. There’s also a handy covered cubby at the end of the door armrests.   

The glove box is a good size and there are two cupholders under a pop-up cover in the centre console.

Of course, the back is where space really counts, and there’s as much room as you’d find in, well… a limo.

Sitting behind the driver’s seat, set for my 183cm position, I enjoyed copious amounts of head, shoulder and legroom. 

There are electric sunblinds for the rear and rear side windows, controlled by buttons in the door as well as the rear seat remote, a 5.7 inch OLED display housed in the beautifully trimmed fold-down centre armrest (which also has a soft close function!). The remote also allows adjustment of the lighting and climate control. Classy.

There’s a shallow storage box and twin cupholders in the armrest, medium size door bins and hard shell pockets on the front seat backs. The rear armrests also feature a small lidded cubby. 

In terms of connectivity and power options there’s wireless Android Auto and Apple CarPlay, a USB-A and USB-C in the front, and an identical pair in the rear, as well as a 12-volt socket in the front and two in the back.

Boot volume is a useful 505 litres (VDA) and the lid is electric, with gesture control. It’s able to easily swallow our three-piece luggage set or the bulky CarsGuide pram. And while the rear seats don’t fold there’s a ski port door to accommodate long items. Just make sure you use the tie-down anchors in the boot to ensure they’re properly secured. There’s a handy netted section behind the left wheel well and a cargo net is included.

Maximum towing capacity, for a braked trailer, is 2.3 tonnes (750kg unbraked) and in more good news, the spare is a space-saver rather than the increasingly prevalent inflator/repair kit.

I recall a Mitsubishi designer telling me, once upon a time, that he dreamed of making ‘a big car on the outside with a very small interior’. Maybe he made the jump to BMW, because that’s pretty much the 8 Series Gran Coupe.

There aren’t many other vehicles on the market, of this size, that offer less space inside. The boot capacity, for instance, is just 440 litres. Competitors like the Audi A7 (535L) and Mercedes CLS (520L) easily outdo it - but at least this car has more boot than the Panamera (405L), though the BMW is a smidge bigger. The cargo space is large enough for a couple of overnight suitcases, but you’re hardly going to fit a family of four’s luggage for a week away. 

And while we’re in the “not quite what you’d expect” column, the back seat space is hardly commodious. There’s enough space for me, at 182cm, to sit behind my own driving position, but not without wishing for a bit more toeroom, headroom and knee space. 

The big centre console section eats into the space in the rear, justifying the brand’s “4+1” seating claim, and unpleasantly it has a hard plastic finish to rest your leg against. Getting in and out of the second row isn’t easy for bigger people, and it’s quite a squat down into the rear seat - it really has taken inspiration from its squashy-back-seated predecessor in that regard.

If you have smaller rear-seat occupants, however, there will be catered for with dual ISOFIX and three top-tether points, plus there are air vents with climate controls (quad zone in total), and two USB-C ports as well. There are sun-blinds on the rear windows, too, which is a plus, and there is a pair of cup holders in the fold-down armrest, and map pockets in the seat backs, too. The door pockets are near-useless, though.

The front seats score better practicality, with bottle holders in the doors, bigger and sturdier cup holders, a covered centre storage bin between the seats with a USB-C port, and a wireless phone charger (Qi) with standard USB port in front of the gear selector.

Above that is the weird, very out-of-place quick buttons (1-8) that BMW could easily do away with, and further up are the controls for the climate control (thankfully with hard buttons for fan speed and temperature), and above that is the media screen, a familiar looking 10.25-inch touch display running BMW OS 7.0. 

The screen is quick and crisp, and is backed up by the rotary controller and buttons on in the centre console area. There’s wireless Apple CarPlay (now at no cost for three years), as well as a built-in SIM card for 4G data and access to the BMW Online news and weather stations, accessed through the screen.  

It’s all pretty easy to use, and the sound system is excellent - the standard setup consists of 16 speakers, with DAB+ digital radio, Bluetooth and USB plus the smartphone mirroring tech, provided you don’t have an Android device, as Android Auto is still missing from BMW’s range.

It’s a nice cabin, but I couldn’t help but thinking that I’d want a little more differentiation from the lesser models in the range if I was spending this much. Especially considering the optional cost of the interior trim fitted to our test car - see below for more detail.

No-one could level the accusation of affordability at the BMW 8 Series Gran Coupe, as it’s one of the brand’s most expensive models.

This one, the M850i xDrive Gran Coupe, is the range-topping version for 2020, with a list price of $272,900 plus on-road costs.

Where does that plot the BMW against its rivals? It’s beyond the level that the existing Audi RS7 Sportback was (last sold in 2018 at $261,140), and the Mercedes-AMG CLS 53, which looks like a value offering at $182,740. Also, it splits the difference between and the Mercedes-AMG GT 4 door Coupe variants (GT 53: $251,140; GT 63: $351,640), and could best be considered a contemporary of the Porsche Panamera E-Hybrid AWD ($252,400) or the Panamera 4S ($316,500).

So, look - competitors might matter to you. But there’s a good chance that if you’re shopping for an 8 Series, you’ve already made up your mind that you want the BMW four-door coupe slugger. So here’s what you need to know about it when it comes to equipment.

Standard it comes with the M Sport styling pack, 20-inch M alloy wheels with run-flat tyres and tyre pressure monitoring, adaptive M suspension with active roll stabilisation, 395mm M brakes, BMW Laserlight headlights, BMW Night Vision infrared camera with pedestrian detection.

Luxury touches include soft close doors, semi-autonomous parking, panoramic glass sunroof (front opening, rear fixed), keyless entry and push-button start and electric auto tailgate, heated and ventilated front seats with electric adjustment including lumbar and bolster, leather seat trim, a 16-speaker harman/kardon sound system, 10.25-inch media screen with gesture and voice control, 12.3-inch digital instrument display, full colour head-up display, ambient lighting and rear sun-blinds. 

You’re getting a lot for your money, though our tester had a couple of extras. Metallic paint is included, but no the Frozen Bluestone matte finish our car had ($2600), and the interior piano black trim elements cost $200, as well. Plus the Full Leather Merino finish in Ivory White and Night Blue - that box cost $10,200 to tick. All told, the price as tested before on-roads was $285,900. 

The Audi A8 50TDI is powered by a 3.0-litre turbo-diesel V6 engine sending 210kW (from 3500-4000rpm) and 600Nm (from 1750-3250rpm) to all four wheels via an eight-speed automatic transmission (with ‘Tiptronic’ sequential manual shift function) and Audi’s quattro constant all-wheel drive system using a self-locking centre differential.

It also features a 48-volt electrical set-up for mild hybrid functionality built around a belt connected starter/generator, AC to DC converter and a 48-volt lithium-ion battery. 

With energy recovery of up to 12kW from regenerative braking, it enables the A8 to regularly coast with the engine switched off and helps the extended stop-start system to operate smoothly. 

If you’re going for the M850i, you’re getting the big bopper engine. It’s a 4.4-litre twin-turbo V8 petrol engine, and it isn’t short on horsepower.

The outputs for this engine are 390kW of power (at 6000rpm) and 750Nm of torque (from 1800-4600rpm). Hardly numbers to sneeze at.

And the performance figures are exceptional, too: the claimed 0-100 km/h time is just 3.9 seconds. That’s because there’s the traction of BMW’s xDrive all-wheel drive system, and shifting gears is an eight-speed automatic transmission.  

For what it’s worth, your humble reviewer saw a 0-100km/h time very close to that (4.2sec). 

The quoted kerb weight for this model is 1995kg.

Audi’s official fuel economy number for the combined (ADR 81/02 - urban, extra-urban) cycle is 6.6L/100km, the 3.0-litre turbo-diesel V6 emitting 175g/km of CO2 in the process.

Over a week of city, suburban, and some freeway running we averaged 11.1L/100km, which is acceptable for a 2.1-tonne luxury sedan.

Also worth noting the standard stop-start system works beautifully thanks to the 48-volt starter/generator.

You’ll need 82 litres of diesel to fill the tank and using the official number, that translates to a range of just over 1240km, which drops to around 740km using our real-world figure.

You can’t really expect a big V8 beast like this to be a fuel miser, and it isn’t.

The claimed consumption is 10.7 litres per 100 kilometres. Which is alright, honestly, given the sheer volume of car you’re driving. 

But on my test - which consisted of more than 300km of mixed driving, including days of city commuting, some twisty mountain driving, and all the freeway floundering to get there - I saw an at the pump real-world figure of 15.4L/100km.

That’s not very efficient, and it’ll be expensive to run on the daily — yet the argument could be made that if you’re spending this much on a car, fuel costs won’t matter much to you. But with a small fuel tank capacity of 68 litres, it could become a little inconvenient as you’ll be seeing a lot of your local servo.

Despite extensive use of aluminium in the ‘ASF’ platform and body panels, the A8 tips the scales at a sturdy 2095kg, yet Audi says the A8 will accelerate from 0-100km/h in just 5.9 seconds. And with 600Nm of peak torque available across a flat plateau from 1750-3250rpm this big four-door gets up and goes hard when asked to. 

At more sedate speeds you’re occasionally reminded there’s a diesel engine under the bonnet, with that characteristic engine and exhaust noise only making their presence felt under pressure. 

In fact, under normal circumstances, noise, be it the engine, tyres or wind is minimal, thanks to a combination of the car’s aero-efficient shape, thick acoustic glass and other sound-deadening measures throughout the car.

The eight-speed auto transmission is suitably smooth, with the central shifter or wheel-mounted paddles able to make snappy sequential ‘manual’ shifts.

There are four drive modes in the ‘Drive Select’ system - ‘Comfort’, ‘Auto’, ‘Dynamic’ and ‘Individual’ - enabling tweaks to the steering, transmission, throttle and suspension. Comfort felt most appropriate most of the time, although dialling up the throttle and transmission to more aggressive modes in Individual adds an enjoyable edge.

The suspension is five-link front and rear with an adaptive air system smoothing even high-frequency bumps and ruts amazingly well.

Push into a corner and the A8 feels nicely balanced, its wide track, sophisticated suspension, plus the quattro AWD system seamlessly distributing drive between the front and rear axles, keeping the big body under control. In fact, you feel the ‘big car shrinking around you’ syndrome from the get-go.

The steering is precise without being overly sharp and road feel is good. Again, with that 2.1-tonne kerb weight in mind, braking is appropriately powerful with big ventilated discs front (350mm) and rear (330mm).

It pays to remember the turning circle is 12.5m, and it’s worth picking your spot for a U- or three-point turn.

Although there’s a lot going on for the driver in terms of screens, buttons and switches it all makes sense ergonomically. The head-up display is helpful and there’s a common sense mix of digital and physical controls, the latter including an audio volume knob. Yes.

It’s an impressive thing, this M850i xDrive Gran Coupe. But I’m just not sure who it’s trying to please.

It’s not the sort of German monster coupe-sedan that grabs you by the scruff of the neck and throws you around with its mammoth acceleration. Not unless you poke it and prod it and make it really angry.

And that might be exactly what you want to do - put it in Sport mode, sling the shifter across to sport or manual mode, hear the exhaust open up from a pursed-lip tongue-click to an open-mouth growl. 

You’ll push hard on the accelerator, watch the tacho needle jolt to the redline, and if you’re in auto mode you’ll feel the transmission whipcrack as it shifts rapidly up through the gears as you’re shoved back into your seat. Before you know it you’ll be in licence-loss zone, and you won’t have even made the tyres chirp - that’s how immense the traction from the all-wheel drive system is.

You’ll brake hard into a sharp bend, and you’ll feel the front end dip and the body of the car change direction more readily than you’d think given its size as you turn in. The steering response will meet your expectation, with rapid reaction to adjustments mid corner. And the Active Roll stabilisation system will mean you’re not being thrown around in your seat, because it’s sitting flatter and truer than you might have expected - you’ll notice how it works extremely well in conjunction with the car’s torque-vectoring-by-braking system. There’ll be little weight shift or body roll to be counteracted, and that’ll inspire you to push it even harder.

Put it in manual transmission mode and you’ll rejoice that it won’t overrule you and shift up, but you’ll also feel shortchanged because it gets to the end of its limit very quickly. And when it hits redline, it emits a breathless little cough rather than a “oh maybe I should stop” rev-bounce noise.

But, if you’re like me, you might be doing all this with a niggling thought in the back of your mind that, while this car is technically really good and it’s a clinical performance car, you might just think to yourself, “I’m not having as much fun as I thought I would”.

A Mercedes-AMG would be more fun; it’d be more raucous, more of a muscle car experience. An Audi RS7 (at least the previous one) would be noisier, brasher, more theatrical than this car. And likewise, a Porsche Panamera - no matter the model you go for - would be more entertaining in the bends.  

Maybe it’s just a bit too predictable - and maybe that’s a result of this car being honed for drivers who will spend more time on the Autobahn than anywhere else. I have to say, there are much, much worse (and slower) ways of getting from A to B, and the highway cruising comfort of the M850i Gran Coupe was what impressed me most. 

It’s also surprisingly adept at urban driving duties, coping well with unpleasant city surfaces, though potholes can still upset things because of the stiff-sidewalled run-flat tyres. The suspension does an exceptional job otherwise, however, and I switched between the Adaptive drive mode and Comfort mode for my commuting duties. Both proved comfortable and controlled.

The M850i is by no means a failure when it comes to fulfilling the expectations you might have of a luxury sports sedan of this size. In fact, it’s close to a distinction. But I just can’t help thinking that it’s not as much an ‘M car’ as that M850i badge might have you believe it should be.

The safety equipment fitted to the BMW M850i Gran Coupe as standard is extensive - but this model has not yet been tested by ANCAP or Euro NCAP, so there’s no safety rating or crash test rating available.

Standard equipment includes BMW’s Driving Assistant Professional system with adaptive cruise control with stop and go in traffic, auto emergency braking with pedestrian and cyclist detection, front and rear cross-traffic alert, lane keeping assist with steering input, blind spot monitoring, “crossroads warning and evasion aid” which can help you steer away from potential danger more easily. 

There’s also a comprehensive camera suite with a reversing camera, surround view and forward view camera setup which can adjust based on what part of the parking manoeuvre you’re up to. Plus if you get stuck, the reversing assistant system can remember the last 50 metres you drove and get you out of the spot. There’s also a thing called Active Park Distance Control rear, which will apply the brakes when you’re reversing if it thinks you’re getting to close to an impact.

There are six airbags - dual front, front side and curtain - with no rear side airbag protection, which seems odd in a car at this price point but is likely down to packaging.  

The A8 is covered by Audi Australia’s five-year/unlimited km warranty, which is now par for the luxury market course, and 24-hour roadside assistance is included for the duration.

Paint defects are also covered for five years, with rust (to the point of perforation) covered for 12. Nice.

Service is required every 12 months or 15,000km with a five-year capped-price plan for the A8 coming in at $3830, or $766 per year. That’s a fair wedge but not outrageous for the category.

BMW backs its cars in Australia with a three-year/unlimited kilometre warranty.

You may be confused if you head to the BMW site and see that M models and 8 Series models aren’t covered by BMW’s pre-pay capped price servicing plan (as I saw when testing this car), but CarsGuide can confirm that the 8 Series is indeed covered - unless it’s the real M8, not this M850i jigger. 

BMW Australia has clarified that the Service Inclusive pack for five years/80,000km of maintenance cover is $2490 for Basic cover (no brakes/pads, no wiper replacement), or $5641 for the more comprehensive Plus pack. Hardly affordable, but nor’s the car. 

The company uses a condition-based servicing program, too - there are no set service intervals, but the car will tell you when it needs maintenance based on how you drive it.

For what it’s worth, we ran the numbers on resale value using Glass’s Guide predictive analysis tool, and after three years/40,000km the expected retained value for this version is approximately 66 per cent - which is impressive.