Audi RS Q8 vs Mercedes-Benz Gls600

What's the difference?

The Audi RS Q8 Performance is a lot - of everything. It offers lots of power, lots of performance, lots of space and lots of luxury. But it’s also a lot of money, and at more than $250k it’s not going to be on everyone’s shopping list. It’s a very niche proposition for a small group of buyers. For those select few, those who want a lot of everything and who crave the ultimate of whatever product they’re buying, then the RS Q8 Performance is going to be a very tempting proposition - even if they never set any lap record in it.

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

It’s big, it’s bold and totally baller, but that’s kind of the point.

The Mercedes-Maybach GLS 600 might not win over many fans with its in-your-face design or its sky-high price tag, but there is definitely an appeal here.

Taking luxury to another level is no easy feat, especially in a Mercedes, but the attention to detail, lavish second row and butter-smooth V8 engine combine to turn the already-good GLS into this exquisite Maybach.

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

We don’t refer to ‘facelifted’ cars for no reason, the RS Q8 Performance has a number of visual changes.

These include a new Audi ‘singleframe grille’ and new front bumper design, with a new Matt Carbon trim package available to highlight that.

There’s also a new rear bumper design as well as new digital daytime running lights at the front and digital OLED lights at the rear.

The unique forged alloy wheels are another design change, but also bring a functional element. Measuring 23 inches they do a good job of filling out the wheel arches and give the RS Q8 Performance a purposeful stance and good proportions. But they are also 5kg lighter per wheel than the 22-inch rims on the RS Q8, saving unsprung weight to help the ride and handling.

Inside, Audi hasn’t made any dramatic changes to the design, which is fine because the brand does some of the best cabins on the market in terms of look and feel.

What is new is an aluminium inlay and an optional RS interior design package which provides a unique finish to the seats, with contrasting stitching, for an additional $4100.

If you have wealth, why not flaunt it? I reckon that might be the philosophy of the Maybach designers back at HQ, and it kind of shows!

The styling of the Maybach GLS might be the most controversial thing about it. But honestly, I love it!

The liberal lashings of chrome, the three-pointed star hood ornament, and especially with the optional two-tone paintwork, it’s all just so over the top and in your face that it brings out a smile.

From the front, the Maybach is also distinguished by an imposing grille that gives it serious presence on the road, while the profile is characterised by massive 23-inch multi-spoke wheels – better park well clear of any gutters!

You’ll also notice the Maybach eschews the usual black-plastic cladding around the wheelarches and underbody found on lesser/cheaper SUVs in favour of body-coloured and gloss-black panels.

There is also a little Maybach badge on the D-pillar, which is a nice attention-to-detail touch. From the rear, there’s more chrome, while the dual exhaust outlets hint at the performance on offer. But it’s inside where you really want to be.

Everything in there is just a sea of soft-touch and premium materials, from the dashboard to the seats and even the carpet under your feet.

Though the layout of the interior mirrors the GLS, the extra detailing, like the Maybach-stamped pedals, unique multimedia surround and woodgrain steering wheel, elevates the cabin into something truly special.

And if you opt for the comfort rear seats, well they wouldn’t look out of place on a private jet.

The second-row seats also feature contrast stitching on the headrests, cushions, console and doors for that add a touch of class.

I can see the Maybach GLS might not be to everyone’s tastes, but it certainly stands out from the sea of samey-looking luxury SUVs out there.

While it’s easy to get swept up in the power and speed of the RS Q8 Performance, it’s important to remember that it’s an SUV and it needs to offer ‘utility’ as well as ‘sports’. 

With that in mind, the front seat occupants are well looked after with supportive and comfortable sports seats, with a good amount of small item storage spaces. 

The rear seats are surprisingly comfortable, despite the sloping roofline of this ‘coupe-style’ SUV. Audi has cut recesses into the ceiling to create more headroom, so it will be fine for anyone under six-foot tall. Despite there being five seat belts, this is realistically more of a four-seater for adults, although three smaller kids could squeeze across the back.

There’s also a pair of cupholders, two USB-C ports, a 12-volt outlet and your own climate controls for the rear passengers.

As for the boot, again it loses some volume because it’s not a wagon-style SUV, but there’s still a decent, square floor space with a claimed 605 litres of capacity.

So, overall the Q8 obviously isn’t the most practical version of an SUV, but it does well given its focus on style.

The Maybach GLS is based on Mercedes’ largest SUV offering to date, which means there is plentiful room for occupants and cargo.

The front row feels positively palatial, with heaps of head-, leg- and shoulder-room for six-foot (183cm) tall adults.

Storage options include generous door pockets with room for large bottles, two cupholders, a smartphone tray that doubles as a wireless charger, and an underarm storage cubby.

But the rear seats are where you want to be, especially with these second-row comfort seats fitted.

It’s rare when there is more room in the rear than the front, but it does makes sense for a car like this, especially when you consider the GLS this car is based on is a three-row vehicle.

The removal of seats six and seven mean there is more room in the second row, especially with the comfort seats fitted, allowing you to recline fairly flat and to get into a comfortable position.

Storage is also plentiful in the second row, with a bespoke centre console in our test car, the aforementioned drinks fridge, backseat storage and a nice door bin.

Open the boot and you will find 520 litres (VDA) of volume, which is plenty for golf clubs and holiday luggage.

However, if you opt for the rear seat refrigerator, the cooler box will eat into boot space.

The best things in life might come free, but the most luxurious things certainly come at a cost.

Wearing a price tag of $378,297, before on-road costs, the Mercedes-Maybach GLS 600 is probably out of the reach for most mere mortals, but there’s no denying Mercedes has thrown in a lot for the spend.

And with it positioned nearly $100,000 north of the Mercedes-AMG GLS 63 ($281,800) – with which it shares its platform, engine and transmission – you’d want to get a bit of bang for your buck.

Standard features include keyless entry, push-button start, Nappa leather interior trim, a head-up display, a sliding glass sunroof, power-closing doors, heated and cooled front and rear seats, and interior ambient lighting.

But, as the epitome of Mercedes’ luxury SUVs, the Maybach also scores 23-inch wheels, a heated woodgrain and leather steering wheel, open-pore wood trim and five-zone climate control – one for each passenger!

Handling multimedia duties is Mercedes’ 'MBUX' 12.3-inch touchscreen display, complete with satellite navigation, Apple CarPlay/Android Auto support, digital radio, a premium sound system and wireless smartphone charger. 

Rear seat passengers are also treated to an entertainment system with TV tuner so you can keep up with the Kardashians from the road, as well as a bespoke MBUX tablet with functions for climate, multimedia, satellite navigation input, seat controls, and more.

Sadly, the Samsung-branded tablet glitched out a few times while we were using different functions and required a reset.

No doubt, a software update can fix some connection issues, but it's still something that shouldn’t be happening in a high-dollar, ultra-lux SUV.

Options with the Maybach GLS are surprisingly limited, with buyers able to choose between different exterior colours and interior trims, second-row comfort seats (as fitted on our test car), and a rear champagne chiller box.

Look, nearly $400,000 for an SUV might seem like a lot, but you really are wanting for nothing with the Maybach GLS, and it's comparable in price to other high-end SUVs like the Bentley Bentayga and Range Rover SV Autobiography.

This is the latest iteration of Audi’s twin-turbo 4.0-litre V8 petrol engine - and it’s a beauty.

While this engine is used in a variety of models, for the RS Q8 Performance Audi has taken power to 471kW with 850Nm of torque, which, as mentioned earlier, makes it the most powerful internal combustion engine Audi has ever offered in a production car.

That’s also a big boost over the previous RS Q8, which managed 441kW/800Nm, and is only just shy of the 485kW/850Nm offered by its ‘cousin’, the Porsche Cayenne Turbo GT.

Audi claims that the RS Q8 Performance will launch 0-100km/h in just 3.6 seconds and keep going to an electronically limited top speed of 250km/h. We tried to test the acceleration time on a closed circuit, but driving into a very strong headwind the big SUV could manage only 4.4 seconds - which is still a very quick time given its size and luxury.

The engine is paired to an eight-speed automatic transmission and Audi’s trademark quattro all-wheel-drive system to help smoothly transmit so much power to the road.

Powering the Mercedes-Maybach is a 4.0-litre twin-turbo petrol V8 – the same engine you will find in many AMG products like the C 63 S and GT coupe.

In this application, the engine is tuned to produce 410kW and 730Nm, which is admittedly less than you get in something like the GLS 63, but the Maybach isn’t designed to be an outright powerhouse.

With drive sent to all four wheels via a nine-speed automatic transmission, the Maybach SUV will accelerate from 0-100km/h in just 4.9 seconds – also helped by a 48-volt mild-hybrid 'EQ Boost' system.

Though not designed for outright grunt, the Maybach GLS’s engine is nicely tuned to deliver smooth power and seemless shifting

The Maybach is more than a match for rivals such as the Aston Martin DBX (405kW/700Nm), Bentley Bentayga (404kW/800Nm) and Range Rover P565 SV Autobiography (416kW/700Nm).

Unfortunately you don’t get the most powerful production engine without some trade-off, and for the RS Q8 Performance that means significant fuel consumption. The official fuel economy rating is a very thirsty 12.2L/100km, but that's the best-case scenario too. If you partake in some spirited driving that unleashes the full potential of the engine will result in a higher rate of premium unleaded being consumed by the big V8. We saw returns in the high teens across our time, but that was largely open road driving, so we’ll reserve final judgement for an extended test drive across more varied conditions.

Thankfully there’s a fairly large 85L fuel tank, so if you can hit the claimed average you can get a theoretical 696km of range.

Official fuel consumption figures for the Mercedes-Maybach GLS 600 are pegged at 12.5 litres per 100km, and it’s recommended to fill up with 98 RON premium unleaded, so be prepared for a big fuel bill.

This is despite the 48-volt mild-hybrid tech that lets the Maybach coast without using fuel in certain conditions, and extends start-stop functionality.

In our brief time in the car, we managed to get 14.8L/100km. Why is the Maybach so thirsty? That’s simple, it’s weight.

All the cool features like Nappa leather interior, woodgrain trim and 23-inch wheels add weight to the overall package, and the Maybach GLS tips the scales at nearly three tonnes. Ouch.

Obviously the RS Q8 Performance is all about speed, Audi made its intention clear by sending it to the Nurburgring to set a new SUV lap record for an SUV. But the reality is most owners are unlikely to hit the racetrack in the RS Q8, so what’s it like on the road?

In a word? Impressive.

While the engine is undoubtedly the star attraction offering up so much effortless performance, the RS Q8 Performance wouldn’t be so quick around the Nurburgring or as nice to drive on the road without its highly advanced chassis systems.

It has an array of technology to help it handle, it has active air suspension, adaptive dampers, active roll stabilisation and all-wheel steering, which help to make this big SUV handle like a much smaller car.

The suspension does a remarkable job of providing a compliant ride on such large alloy wheels, while also providing responsiveness.

The handling is certainly helped by the all-wheel steering, which gets the rear wheels to turn in the opposite direction to the fronts at low speed (below 50km/h), but in the same direction at high speed (above 80km/h), making the big SUV feels much more direct when changing direction.

As for the overall experience, that’s helped by Audi’s surprising decision to actually remove some of the sound insulation, which allows you to hear the engine even more than you ordinarily would. This really plays to the dynamic nature of the RS Q8 Performance.

While you might not find many owners of the Maybach GLS in the driver’s seat, it’s nice to know it can hold its own in the driving dynamics department.

Don’t get me wrong, this won’t give the AMG-blessed GLS 63 a run for its money, but the Maybach SUV is far from dull.

And the engine plays a large part in this. Sure, it’s not as savage as some AMG models, but there is still plenty of grunt to come out of corners with enthusiasm.

The tune of the engine is obviously weighted towards smoothness and comfort, but with 410kW/730Nm on tap there is enough there to make things feel urgent.

The nine-speed automatic transmission also has to be called out, as it is calibrated in such a way that the shifts are imperceptible. There’s none of that mechanical jerkiness and clunkiness involved in swapping cogs, and it just makes the Maybach GLS feel that much more luxurious.

The steering, while straying a towards numb, still offers plenty of feedback so you know what’s happening underneath, but it’s the active body control that works to keep this hefty SUV in check in the bends.

The best bit, though, has to be the air suspension, which floats the Maybach GLS over bumps and uneven roads like a cloud.

The front-facing camera can also read the terrain ahead and set-up the suspension for incoming speed bumps and turns, taking comfort up to a whole new level.

All this is to say, yeah, the Maybach might look like a boat, and cost as much as a boat, but it doesn’t actually feel like a boat behind the wheel.

But really, are you buying this car because you want to be the driver? Or are you buying one because you want to be driven?

In the second row, it’s as close as you’ll get to a first-class flight on the road, and the seats are genuinely plush and cosy.

It’s eerily quiet and supremely comfortable in the second row, leaving you free to carry on with important business like drinking your champagne or uploading to the 'gram.

And while I usually suffer from a bout of motion sickness within minutes of looking at a phone in a car, I didn’t feel such ill effects in the Maybach GLS.

Even after about 20 minutes scrolling through Facebook and emails while being driven around, there was no sign of a headache or queasiness, which is all thanks to how well the suspension is tuned and the active anti-roll technology doing its thing.

The Mercedes-Maybach GLS 600 has not been tested by ANCAP or Euro NCAP, and therefore doesn’t wear a safety assessment rating.

Despite this, the safety equipment found on the Maybach is comprehensive. As standard, there are nine airbags, a surround-view camera system, autonomous emergency braking (AEB), tyre pressure monitoring, traffic sign recognition, front and rear parking sensors, rear cross-traffic alert, and automatic high beams.

Mercedes’ 'Driving Assistance Package Plus' is also included, bundling adaptive cruise control, lane-keep assist and blind-spot monitoring.

The 'Urban Guard' suite also adds an alarm, tow-away protection, parking damage detection, and an interior motion sensor, which can send notifications to your 'Mercedes Me' app.

Despite the extra power and fancy new brakes, the RS Q8 Performance costs the same to service as the existing RS Q8.

That means $4690 for Audi’s five-year service plan, and $5720 for the Audi Advantage.

The latter package includes an extra two-year, unlimited kilometre warranty on top of Audi’s five year/unlimited km coverage. It also includes two extra services and two more years of roadside assistance, to keep you covered for seven years total.

That’s good, but it’s still an extra cost when many mainstream brands already offer seven years of coverage as standard.

Like all new Mercedes models sold in 2021, the Maybach GLS 600 comes with a five-year/unlimited kilometre warranty with roadside assist over that period.

This is class-leading in the premium segment, with only Lexus, Genesis and Jaguar able to match the warranty period, while BMW and Audi serve up assurance periods lasting only three years.

Scheduled servicing intervals are every 12 months or 20,000km, whichever occurs first.

While the first three services will cost owners $4000 ($800 for the first, $1200 for the second and $2000 for the third service), buyers can opt to save some money with a pre-paid service plan.

Under the service plan pricing, three years of maintenance will cost $3050, while four- and five-year plans are on offer at $4000 and $4550 respectively.