Audi RS Q8 vs Mercedes-AMG GLE53

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.

The GLE Coupe isn't going to click with a traditional enthusiast but will appeal to a new age of mainstream performance buyers. It's a total tech showcase and you can feel all of those 48-volt benefits from behind the wheel.

Love it or hate its shape, then, you have to appreciate how Mercedes has gone to the nth degree on the details on an SUV it probably could have sold on looks alone.

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.

Hate the very concept of a large SUV coupe or not, you have to at least agree this second-generation GLE Coupe looks infinitely better than the model preceding it.

This time the Coupe version was front of mind from the outset of the GLEs development and is significantly different from the wagon version in more ways than just a sloping roofline.

The wheelbase has been cropped in 60mm compared to the wagon, and the GLE Coupe is a full 7.0mm wider and 39mm longer than its predecessor.

All this adds up to an imposing and more resolved SUV Coupe. I especially like the way its bootlid flicks up into a spoiler, and how the tail-lights round out the profile nicely.

Still, there's always going to be something a little off about the proportions when it comes to a coupe SUV this big, and it's certainly a re-imagining of what a sporty vehicle should look like.

This car's cabin is almost as confronting as its exterior. Up front you're met with an assault of chrome, a ventilation overload and a totally dominant expanse of screens.

This all hints at the advanced tech which lies beneath, but the real wood and leather trims also elevate the cabin to something you might expect at the tall asking price.

It may appeal to a particular taste and makes the BMW X6's cabin look almost conventional.

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.

In some ways, the GLE Coupe makes the most of its extra dimensions, but in other more obvious ways, it's quite compromised.

Benz tells us there's now 40 litres of combined cabin storage, and with the large door bins, centre console box, convertible cupholders, and glove box, I'm inclined to believe them.

The brand also told us much of the extra 39mm of body length has gone into the rear passenger space, and this seems true when it comes to legroom.

You definitely notice the decline of the C-Pillar, though, making an otherwise large space feel slightly claustrophobic, particularly with the 53's dark headlining and heavily tinted rear windows.

The almost absurd ride height does make peering over the bonnet a chore at times, although I enjoyed the adjustability and comfort afforded by the front two seats.

In terms of connectivity, front passengers get a plethora of USB-C jacks, a wireless charging bay, and a 12V power outlet. There's no USB-A connectivity, so you'll want to stock up on converters.

Rear passengers benefit from dual USB-C ports in a fold out tray, and also score dual adjustable air vents. Two extra climate control zones can be optioned for rear passengers ($1450), and there's also an exorbitant option package to include two screens and wireless headsets for the full business-class experience in the back seats ('Entertainment Package' - $6000!).

You might be surprised given this SUV's shape, but a lot of thought was also poured into the design of the boot area. Thanks to a large footprint, the GLE 53 Coupe's boot is large at 655 litres, five litres up on its predecessor. It's still a whopping 170-litres down on the wagon version, though.

The boot lip has been lowered significantly to increase ease of use, too.

Our test car did not have a spare wheel, with only an inflator kit or run-flat tyres to be working with. This is despite a large area under the boot floor which, to my eyes at least, could easily have fit a space-saver spare.

Does price matter when it comes to a machine like this? The GLE 53 variant with which this generation of Coupe will launch is the mid-grade car in a three-variant line-up.

It wears a very premium MSRP of $171,800. Soon it will be joined by the only non-AMG badged variant, the GLE 450 Coupe ($137,000) and the top-spec V8 bruiser, the GLE 63 S ($222,700).

To put those numbers (and this car's very existence) in context, it's best to look at its direct competitors.

You'll likely know of its arch rival, the BMW X6. Another Coupe SUV at the pointy end of the price scale, the closest rival variant to our GLE 53 is the M50i starting from $159,900.

Other rivals in this rapidly growing space include the Porsche Cayenne Coupe S at $166,200, and the yet-to-arrive Audi SQ8 which has not yet had its pricing locked in for the Australian market. See what I mean? Coupe SUVs are beyond just an oddity.

So, it's more expensive than its direct rivals, but does it have good reason to be? The GLE 53 is equipment laden from the get-go.

Included are the standard fitments from all new Benz models, including the headline dual 12.3-inch screens adorning its massive dashboard, complete with Apple CarPlay, Android Auto, built-in navigation and voice activation, real leather interior trim with fully electrically adjustable heated and cooled front seats, 21-inch alloys, 'multibeam' LED headlights, AMG styling items, a wireless charging bay, head-up display, and, of course, a panoramic opening sunroof.

An impressive list, but the technology under the skin of the new GLE goes a step beyond. Read about its engine and transmission tech and impressive safety suite later in this review.

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.

Here's where this car gets particularly interesting. It's a hybrid. But not your gran's Prius. It's hybrid in a way which will make you re-think the technology.

Residing under the bonnet is a 3.0-litre, twin-turbo, straight-six engine mated to a very complex looking nine-speed (torque converter) automatic transmission.

One of those two turbochargers is driven by an electric motor rather than the exhaust (in order to provide its peak benefits at the lowest possible rpm), and there's also an electric motor inside the transmission which takes the load off the engine at low speeds and between gears.

This isn't where the 48-volt tech ends, with the GLE 53 also sporting active anti-roll bars and dampers, which significantly adjust the ride and body-roll on-the-fly.

All four wheels are driven via Benz's 4MATIC+ all-wheel drive system.

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.

It's a performance car, so fuel consumption is probably not going to be front of mind for potential buyers. That said, the hybrid tech delivers a surprisingly good number.

The official combined cycle consumption number is ambitiously under 10L/100km at 9.3L/100km.

After three days of (roughly) combined testing and about 300km of distance travelled, our car was showing a dash-reported 14.1L/100km. Not near the claim, but is it really bad for a performance SUV weighing 2447kg? I would argue, not.

The GLE 53 requires the top-shelf 98 RON hydrocarbons to fill its 85-litre tank, giving it a maximum theoretical range of 726km between fills.

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.

This Benz feels about as imposing from behind the wheel as it is to look at. Straight away, you'll notice you tower over the road. I felt as though I was sitting high enough to be on the roof of passing hatchbacks, so there's nothing traditionally 'sporty' about it from the get-go.

I know you're probably thinking visibility is average with that roofline, and you'd be right. You just can't see much, full-stop, out the back.

Thankfully, an array of sensors and very wide-angle mirrors help with overall visibility, so you won't have to be too paranoid about unseen vehicles in your blind spots.

I'm pleased to report all the technology which goes under this SUV's skin is evident when it comes to the drive experience.

The hybrid tech is ultra-slick and impressive in every department, from trawling in traffic to the curvy stuff and the open road.

The responsiveness of this powertrain is something to be experienced (with the pre-spooled turbo) and the way the hybrid motor in the transmission smooths out shifts removes all the worst characteristics of a traditional torque converter automatic.

One thing to note about the GLE 53 – while it's quick, it's not quite a fire breather. There's no getting around this car's almost two and a half tonne weight, and while I love the smooth feel and note of the 3.0-litre straight six, it's simply not as thunderous or full of theatre as I imagine the 63 S will be.

Despite its height and weight, the altered steering ratios and 48-volt driven suspension and anti-roll systems cause a suspense in belief when it comes to the corners.

And grip levels are certifiably absurd with those gigantic rear tyres also pitching in to do their part to help something this large deny gravity and physics.

It's not all amazing though. You really feel every millimetre of this SUVs width, and at the end of the day there's no getting around it. It just doesn't feel anything like a sports machine in the traditional sense.

When it comes to ride quality, the GLE impresses, but has its limits. Sure there's air suspension at work, but it offers up nowhere near the ride quality of the more comfort-tuned GLC 300e I recently tested.

Seems as though there's an inevitable cost to keeping the GLE feeling well and truly planted at all times.

On the freeway the GLE Coupe is ridiculous in the way it can basically drive itself, so this offers up a real plus for those looking for a balance of performance and sensibility for longer trips.

It would be no good having a 2.5-tonne rolling tech showcase without top-tier safety to match, and the GLE 53 Coupe doesn't disappoint.

Standard is autobahn-spec auto emergency braking, which combined with lane change assist is beyond just the radar cruise in most cars, it's truly autonomous.

Don't try this at home, but the GLE is capable of completely driving itself on the freeway should you... theoretically... let go of the wheel.

Also included is blind spot monitoring, rear cross-traffic alert, traffic sign recognition, and driver attention alert.

There's a top-down camera suite, too (will help maneuvering given it's tough to see over the dash and out the back), and a compliment of nine airbags.

You won't be surprised to hear the GLE range is covered by a maximum five-star ANCAP safety rating to the stringent 2019 standards.

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.

Mercedes has recently made a jump to the front of the luxury segment, offering an industry-wide standard of a five-year/unlimited kilometre warranty. Here it is only rivalled by Korean newcomer, Genesis.

Service intervals occur once every 12 months or 25,000km and prices can be pre-packaged at a discount.

A three-year service plan can be had for $2800 ($3500 if you choose to 'fix' the price), four years can be had at $3800, while a full five-year plan will set you back $5200. Not cheap, but then, neither is the car itself...