Mercedes-AMG GLC43 vs Audi RS Q8

What's the difference?

The Mercedes-AMG GLC43 has your back if you’re looking for a thrilling performance SUV that moonlights as the daily family driver. It boasts a fairly practical cabin with good storage. Is it too expensive? Yep. Would I have one? Absolutely. It’s fun and full of features.

This rocked my kid's world – the lighting, the cool superhero vibes of the styling … the ‘tatatata’ chirps of the engine. It won him over completely.

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 GLC43 looks distinctly more aggressive than its GLC300 sibling.

The grille features vertical struts instead of the star motif and there’s a sporty spoiler lip at the rear that complements the quad exhausts.

The large headlights featuring Mercedes Digital Light LEDs dance when you first put them on and add a sporty dynamic to the styling, as does the 20-inch alloy wheels.

The interior is largely the same with a dashboard that is headlined by an 11.9-inch touchscreen multimedia system and a 12.3-inch digital instrument cluster.

The ambient lighting system transforms the space at night time and honestly, makes it look pretty flash compared to some of its rivals. I also love the big panoramic sunroof and cute circular air-vents found in the front – they add some interest to the cabin.

The optioned performance seats of our test model make this look the part of a performance SUV and there is AMG badging everywhere - just so you don’t forget what you're driving. This looks beautiful inside and out and it earns its luxury tag.

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.

The cabin up front feels like a cockpit because the optioned performance seats absolutely lock you into place.

The adjustments are pretty good for the lumbar and under-thigh supports but the highlight are the kinetic stretching massage functions on both front seats, it really helps to alleviate fatigue on a longer journey. 

While I find the seats comfy, my husband didn’t! He said he needed more ‘space’ between the legs and with the bucket-style, he um … didn’t get that required space. Take from that what you will.

Getting in and out of the backseat is easy enough but the side steps are overkill and can dig into the calves.

The back seats are not super comfortable as they are on the harder side but the headroom and legroom are great for my 168cm height. The back row would still be most comfortable as a four-seater when filled with adults, though.

The individual storage is excellent up front with a decently sized glove box, middle console and a huge storage bin and drink bottle holder in each door.

The centre console features a good-sized cubby that includes a phone shelf and two retractable cupholders.

The storage and amenities in the rear are okay with directional air vents, reading lights and a fold-down armrest with two cup holders. You also get shallow storage bins in each door but this row misses out on charging options, which is a shame.

The other technology looks high-end and the graphics in both the 11.9-inch touchscreen multimedia system and 12.3-inch digital instrument cluster assert that the GLC43 is a luxury vehicle.

Both are easy to use, highly customisable and look fantastic. What a combo!

The augmented reality satellite navigation shows dynamic directions overlaid on a live video feed, so there's no excuse for getting lost while using it. There's also wireless Apple CarPlay and Android Auto, as well as, a Mercedes Me Connect app, so you can access features on your car remotely.

Charging options are only found in the front row but you get a good selection with three USB-C ports and a wireless charging pad.

The GLC43 gets a large coloured head-up display, fingerprint scanner (that can lock a certain profile or features) and dual-zone climate control but it would have been nice to see climate control in the rear row as well.

The boot is pretty large for a medium SUV at 620L, and can comfortably fit shopping or luggage.

There’s a tyre mobility kit and extra underfloor storage, and the rear row has a 40/20/40 split fold, which opens up your storage options. You also get a powered tailgate in this model, which is always handy.

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.

Audi updated the Q8 range earlier this year, with refreshed looks after seven years on sale and a plug-in hybrid powertrain to cater for new demand.

A new RS Q8 is coming later in the year, but the RS Q8 Performance has arrived first to make a bigger impact. It naturally gets a performance boost, but there are some other extras beyond more kilowatts.

These include RS ceramic brakes, lightweight 23-inch forged alloy wheels, Pirelli P-Zero tyres, unique aluminium inlays and a special RS layout for the digital instrument display.

Which is good, because the RS Q8 Performance costs nearly $25k more than the ‘standard’ RS Q8, priced from $255,800 plus on-road costs.

Luckily for a car costing a quarter of a million bucks, there’s also plenty of luxuries too, including Nappa leather upholstery, four-zone climate control and a 17-speaker 730-watt Bang & Olufsen sound system, amongst others.

When you compare it to its rivals on performance terms, in particular the Urus and Cayenne Turbo, the $250k asking price doesn’t exactly look ‘cheap’ but it is good value in comparison.

The Audi is a touch pricier than the BMW X6 M Performance at $250,900, but quite a bit more affordable than the Mercedes-AMG GLE63 S Coupe at $268,900.

The 43 gains the 2.0-litre four-cylinder turbo-petrol engine from the AMG A45 hot hatch, which replaces the 3.0L turbo V6 from the previous model.

What makes this one interesting is that it’s been designed with Formula 1 tech and its performance is boosted by an electric turbocharger. Which means you have instant power delivery.

The new engine produces a power output of 310kW and 500Nm of torque. So, a little more power (23kW) but a little less torque (20Nm) than the previous model. The GLC43 is an AWD and has a nine-speed auto transmission which is mostly smooth.

The new GLC43 features a true AMG engine and that means it was hand-built by a master engine builder. Every AMG engine features a plaque with the builder's signature, which is very cool.

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.

You might be surprised given its outputs, but the new GLC43 is fairly frugal when it comes to consumption.

The official combined fuel-cycle consumption figure is 9.9L/100km and my real-world usage came out at 8.8L.

I have put the GLC43 through its paces too – mountain roads, urban and long trips … and have not been shy using it’s power.

That's excellent usage for such a powerful SUV but expect higher in an urban setting.

Based on the official combined fuel cycle and 62L fuel tank, expect a theoretical driving range of 626km.

Mercedes recommends a minimum 98-octane unleaded petrol to be used.

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.

After driving the GLC43, it proves why its considered a performance SUV – the new engine and that Formula One tech creates a fun on-road experience. 

Power delivery is quick and stable – you never feel overwhelmed by what the car is doing but you do get excited.

It has a dedicated 'Track Pace' feature for when you take it to a race track. I mean … is that needed for a family car? Probably not but it’s cool nonetheless.

This new model sees a redesigned adaptive suspension and rear axle steering. The suspension is firm and it hits the road with a definitive thump. I like the feedback when I’m pushing it around bends but for the daily school run, it’s a pretty hard ride.

The rear axle steering is fantastic when you hit big mountain hair-pin turns or need to manoeuvre precisely in your lane. It’s extremely agile on the road, when it needs to be. 

It’s a bummer that the cabin is loud with road noise and while you can do long journeys, just know it’s not a comfort tourer. You drive this for the fun factor.

All of the pillars are quite wide, which I found impeded my vision on bends but on the straights it was fine. I just did more of a weave and bob to check all of the blind spots this week.

Because of the electric turbocharger, power stays high but revs low at lower speeds. This can make parking can feel a little bunny-hoppy at times until you get used to how to accelerate at low speeds. Once you do, it’s a breeze to park and the 360-degree camera is top-notch.

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.

The RS Q8 Performance comes stacked with the full suite of active safety features. These include adaptive cruise control, lane change warning, rear cross-traffic alert and surround-view cameras.

ANCAP rated the Q8 as five stars back when it first launched in 2019 and that rating is due to expire at the end of 2025. However, ANCAP states that it only applies to the 3.0-litre Q8 models, not the V8-powered RS variants.

The GLC comes with a five-year/unlimited kilometre warranty, which is a normal term for the class.

You can pre-purchase either a three-, four- or five-year servicing plan, priced at $4420 for three years, $5520 for four and $6245 for five years. 

Services on the five-year plan cost an average of $1249 per service which is very expensive for the class.

Servicing intervals are reasonable at every 12 months or an extra-long 25,000km, whichever occurs first.

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.