Audi RS Q8 vs Lexus Gx550

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 new Lexus GX 550 Sports Luxury looks fantastic and has enough mod cons to satisfy a family but it’s not as luxurious as you’d expect from a premium brand and the fuel economy and driving range will turn off some. But if you’re still interested, there’s a lot here that will make you happy and it’s one of the smoothest 4WDs I’ve driven.

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 new GX 550 looks massive and while it shares the same platform as the Toyota LandCruiser 300 series, it doesn't share all of its bulk. They both stand at 1980mm wide but differ on length (5015mm vs 4980mm) and height (1670mm vs 1950mm), respectively.

The new design is fabulously rugged but each body panel looks meticulously crafted and is just the right size. This just means the proportions look right and your eye sort of glides over the big body rather than stopping on any one feature.

But having said that, there are a lot of nice features to focus on, like the long LED headlights and rear strip light, auto-folding side steps, 22-inch alloy wheels and sharply styled rectangular side mirrors.

The tailgate window can also be opened if you need to pop something into the boot but don't want, or have the space, to open the tailgate itself.

The styling takes a minor nose dive once you hit the cabin, though, because it doesn't look as sumptuous as you'd expect in a premium SUV.

I love the utilitarian and military vibe of the vertical dashboard, chunky air vents and relatively small windscreen. It looks great but some trims are plasticky and the touchpoints, while soft, are not Lexus-plush.

However, the technology looks gorgeous with an integrated 14-inch multimedia display and a 12.3-inch digital instrument cluster. The fixed sunroof with its two settings (clear or opaque) is also a lovely feature.

But on a whole, the GX 550's European rivals outclass it with their flashier cabins.

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 cabin of the new GX 550 is fairly practical with plenty of head- and legroom in each row (yep, even the third!). When you first hop in, it can feel a big snug on elbow-room but this feeling quickly dissipates.

Despite a 215mm ground clearance, access is pretty good for the front and middle rows due to the wide door apertures and side-steps. Third row access is a bit awkward for an adult but my eight-year old loved scampering back there this week.

The electric front seats are comfortable with their extra functions and I like the way the massage feature extends to the seat cushion as it limits fatigue on longer journeys. However, you sit on top of them rather sink into them which makes it feel a little trucky at times.

The wide middle row has a bench seat that will be comfortable for kids but an adult might get a sore behind on a long trip. The transmission tunnel also compromises foot room for adults but the seat is wide enough to make use of all three top-tether anchor points (there are ISOFIX mounts too).

It was a little bit of an effort to lift my big booster seat into the back because the GX 550 sits so tall but otherwise, there's plenty of room around a child seat for them not to feel like a sardine.

Individual storage is made up of a glove box that fits an owner's manual, a small shelf in the dashboard and a middle console that doubles as a cool box (mini fridge) and can fit up to four cans or bottles in it.

Each row gets four drinkholders and two USB-C ports but the front also enjoys a 12-volt socket and wireless charging pad. There's a 220V domestic plug port in the boot for larger appliances, too.

It's sometimes awkward to use the wireless charging pad because it's easy for your phone to slide around on it and it quite often disengaged from charging.

My son enjoyed all of the other amenities in the middle row, like the reading lights, climate control, two USB-C ports and retractable sunblinds and I applaud carmakers when they position rear directional air vents in the pillars and/or roof. It just makes it so much easier to cool down sweaty kids!

The 14-inch multimedia display has clear graphics and a responsive touchscreen. The layout is easy enough to get used to after spending some time with it and the sat nav is simple to use.

I like that the sat nav directions can be pulled into the 12.3-inch digital instrument cluster and head-up display.

There is a Lexus connected services app, which you get a three-year subscription to. It's easy to connect to the wireless Apple CarPlay and there is also wireless Android Auto.

The system also has Bluetooth and digital radio, which is a delight to use through the 21-speaker Mark Levinson sound system.

The cabin is rounded out by the well-shaped boot which has a massive 1063L of capacity when the third-row is folded. That's been more than enough for my family's needs this week and my German Shepherd was pretty comfy back there, too. The powered tailgate has a kick-function and there is a full-size spare wheel underneath the car.

The Lexus GX 550 shares the same platform as the recently introduced Toyota Prado but both models are now based on the same 'body-on-frame' platform shared by the beastie Toyota LandCruiser 300 Series. So it's bigger and features a more rigid chassis than before.

Surprisingly, that hasn't translated to a massive price tag for the GX 550 and you can pick up the flagship grade on test for this review for $128,200, MSRP.

Which sounds inexpensive when you compare it to the BMW X7 xDrive 40i M Sport which is priced from $171,300 MSRP but the Land Rover Defender 110 P400 X-Dynamic HSE is a lot closer at $128,815 MSRP.

The only issue here is that shared platform, because while they don't share the same powertrain, the flagship Toyota Prado Kakadu ($99,990 MSRP) is still almost $30K more affordable and boasts a similar equipment list. So, ask yourself, is it the brand and engine you're after or the new good looks?

The standard equipment is well-rounded with a 14-inch touchscreen media display with satellite navigation and wireless Apple CarPlay and Android Auto.

A fully digital 12.3-inch instrument cluster, colour head-up display, three-zone climate control and a 21-speaker Mark Levinson sound system round out multimedia requirements.

Other technology includes a digital rear view mirror, two USB-C ports in each row, a 12-volt socket, a 220-volt domestic outlet and a wireless charging pad.

There are two particularly handy features for families, the 'cool box' (basically a mini fridge) middle console and rear retractable sun-blinds.

The fixed panoramic sunroof features two settings allowing you to make it clear or opaque. The electric front seats feature heat, ventilation and massage functions and the rear outboard seats are heated as well. The third row electrically adjusts and there are multiple buttons throughout the car to access this feature.

Upgraded leather-accented upholstery is standard in the flagship grade and is available in three combinations. The Sports Luxury also features 22-inch alloy wheels, a full-size spare wheel and a powered tailgate with kick-function.

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.

All GX 550 grades share the same 3.5L V6 twin turbo-petrol engine which produces up to 260kW of power and 650Nm of torque.

This 4WD has high- and low-gearing, as well as a bunch of driving modes to suit most occasions, like 'Eco', 'Comfort', 'Sport' and 'Sport+'.

The 10-speed automatic transmission shifts through its gears smoothly and it always feels like it's engaged in the right gear. Which isn't always the case for a big SUV!

The Sports Luxury is fitted with a towing hitch and cover but unlike the base Sports grade which has a 3.5-tonne braked towing capacity, this model only has a 3130kg capacity which might not appeal to families with big toys to tow. 

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.

I didn’t have high hopes for fuel economy because the official combined (urban/extra-urban cycle figure is a hefty 12.3L/100km but after mostly open-road driving, with some urban stuff mixed in, my real-world average came in at 11.8L.100km! This figure is based on my actual km travelled (358km) and litres of fuel used (42.41L).

While I’m surprised by the fuel usage result, I wouldn’t say this car has good fuel economy compared to its diesel-powered counterparts but it’s not terrible!

The GX 550 has a relatively small fuel tank compared to its Toyota cousins at 80L and based on the combined fuel cycle, you’ll get a theoretical driving range of up to 650km.

Not all that great. Not for a big family mover and not if you’re typically driving in the city, where fuel usage will be a lot higher.

The GX 550 only accepts premium unleaded petrol (95 RON), too.

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.

Oh my goodness the Sports Luxury is a masterclass on 4WD refinement! You never feel the bulk or weight of this massive SUV when you’re driving it. The power delivery is effortless and there’s lots of grunt available when you hit hills.

The handling is also very good with responsive steering and enough road feedback as a driver to make you feel comfortable with what the car is doing. There is some roll in corners but it can tackle more corners at speed than I thought it would. 

The high driving position makes me feel like I can see a long way ahead yet while visibility is mostly good, it can be compromised when you have the side window shades and the third row headrests up. Which is why I love the digital rear view mirror.

Overall, ride comfort is good with forgiving suspension and low cabin noise, even at higher speeds. It’s pretty easy to chat with all rows and there’s not a lot of engine noise which adds to the refinement. I do like hearing a V6 rumble but that’s just a personal preference. 

I was a little worried about hitting my local Westfield car park but this is a nimble SUV to manoeuvre and parking it is a breeze with the 360-degree camera system and parking sensors. 

The new GX 550 hasn’t been tested by ANCAP and is unrated but its cousin, the Toyota Prado, which shares the same platform just achieved a maximum five-star rating from assessment in 2024. It's fair to expect a good result for this model.

Overall, the Sports Luxury has a long list of standard safety equipment and features nine airbags which is good for a family SUV. 

Safety equipment includes adaptive cruise control, lane departure alert, lane keeping aid, traffic sign recognition, emergency steering assist, driver monitoring, safe exit assist, emergency call functionality, blind-spot monitoring, rear cross-traffic alert and tyre pressure monitoring.

The GX 550 has autonomous emergency braking (AEB) with pedestrian, cyclist, motorcyclist and junction turning assist.

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.

Lexus offers the GX 550 with a five-year/unlimited km warranty, which is fairly standard compared to its Euro rivals.

You get five years capped-priced servicing which costs $5950 but the servicing schedule is a bit of a bear at every six months or 10,000km, whichever occurs first.