Mercedes-Benz GLS-Class vs Audi RS Q3

What's the difference?

The GLS63 is an intimidating beast from afar, but it rewards its occupants in almost every way. Yep, there really isn’t a box it doesn’t tick without serious compromise, such is its breadth of capability.

If there was ever a Swiss Army Knife of cars, the GLS63 is definitely a contender for the title, one that makes it very hard to wipe the smile off your face. Just make sure you can fit it in your garage first…

The Audi RS Q3 Sportback edition 10 years is dynamically brilliant, beautifully finished and surprisingly civilised on day-to-day duty. A polished compact performance package that even in this special 'get-it-while-you-can' guise offers compelling value relative to its direct competitors.

If the GLS63 was a Marvel superhero, it would undoubtedly be the Hulk. Simply put, it has road presence like few others. In fact, it’s frankly menacing.

Of course, the GLS is already pretty intimidating due to its sheer size and blocky design, but the GLS63’s full-fat AMG treatment takes it to another level.

Naturally, the GLS63 gets an aggressive body kit, with its purposeful bumpers, side skirts and rear spoiler serving as instant reminders of what you’re dealing with, but it’s AMG’s signature Panamericana grille insert that really hammers home the point.

Around the side, the GLS63’s 22-inch alloy wheels with staggered tyres (front: 275/50, rear: 315/45) make their presence known, positioned below the wheelarch extensions.

That said, some fun’s also had at the rear end, where the GLS63’s diffuser element integrates the foreboding sports exhaust system with quad tailpipes very neatly.

The focused Multibeam LED headlights also look the part, while the opposing LED tail-lights tie everything together outside quite nicely.

Inside, the GLS63 stands out from the GLS crowd with its sports steering wheel with Dinamica microfibre accents, and multi-contour front seats, which are covered in Nappa leather alongside the armrests, dashboard and door shoulders and inserts.

Of note, the doors bins are unfortunately of the hard plastic variety, which is very disappointing in a vehicle that costs this much. You would expect that cow hide would also been applied to them, but alas it isn’t.

The GLS63’s black headliner serves as an obligatory reminder of its sporting intent, and while it makes for a dark cabin, metallic accents are prominent throughout, while the optional trim (our test vehicle had carbon-fibre) mixes things up, alongside the ambient lighting.

And let’s not forget the GLS63 is still loaded with plenty of cutting-edge technology, including a pair of 12.3-inch displays, with one the central touchscreen and the other the digital instrument cluster.

Both are powered by Mercedes’ class-leading MBUX multimedia system and feature Apple CarPlay and Android Auto support. This set-up arguably remains the best there is today thanks to its speed and breadth of functionality and input methods.

There's a lot going on with the RS Q3's exterior design; a mix of jagged lights, hard character lines, broad haunches and multiple vents surrounding the brand's signature, six-sided grille up front.

The big 21-inch rims fill the arches nicely and the rear features a deep diffuser with fat exhaust finishers poking out either side.

It's a purposeful, macho look and the Sportback edition 10 years is defined by a black package which adds gloss black to the side window trim, front spoiler blade, side blades, rear diffuser and exterior mirrors.

The limited edition is available in two colours, 'Chronos Grey metallic', which is unique to this model and 'Dew Silver matte' which will now be added to the broader RS Q3 colour palette.

Premium performance feels like the dominant theme inside with a typically Audi tech-focused approach including high-quality brushed metal elements, matt carbon inserts and quilted leather trim on the heavily bolstered front seats.

A meticulous attention to detail is obvious and the bottom line is it's all about the driver. A grippy, flat-bottom, leather-trimmed steering wheel looks as good as it feels, sleek screens enhance the racy vibe and the mix of physical and digital controls is sensible.

Measuring 5243mm, 2030mm wide and 1782mm tall with a 3135mm wheelbase, the GLS63 is an upper-large SUV in every sense of the term, which means it’s also very practical.

For example, cargo capacity below the load cover is decent, at 355L, but stow the 50/50 power-split-folding third row via the boot and it’s very good, at 890L, or drop the 40/20/40 power-split-folding middle bench, too, and it becomes a cavernous 2400L.

Better yet, the boot’s aperture is almost square, and its floor’s flat, while there’s no load lip to contend with, making loading bulkier items even easier. Up to four tie-down points are also on hand (depending on seating configuration) to secure loose cargo.

Under the false floor is the space-saver spare, which is to be expected, but what isn’t expected necessarily is the fact there’s also enough room there for the cargo cover when it’s not in use, which would be the case if six or more passengers are regularly onboard.

Moving into the power-sliding second row, the GLS63’s practicality is once again brought to the fore, with up to six-plus inches of legroom available behind my 184cm driving position.

There’s also two inches of headroom with the panoramic sunroof in situ, not to mention just enough toe-room. The GLS63’s small transmission tunnel and sheer width also mean three adults can be seated on the middle bench with few complaints.

Amenities-wise, the second row has map pockets on the front-seat backrest and a small fold-down cubby below the rear climate controls, with it containing two slots for smartphones and a pair of strategically placed USB-C ports.

The rear door bins can take one large bottle each, while a fold-down central armrest is also on hand, featuring a shallow tray and retractable (and flimsy) cupholders.

Alternatively, the $2800 Rear Seat Comfort Package fitted to our test vehicle subs in a tablet that can control the multimedia system, a wireless smartphone charger and a small cubby into the former, as well as a heated/cooled cupholder atop the rear of the centre console.

In the third row, it’s not quite as roomy if you’re an adult. With the middle bench in its most accommodating position, my knees still brush up against its backrest, which is to be expected given it’s primarily designed for children. I also have an inch of headroom there.

Nonetheless, getting in and out of the third row is relatively easy as the power-operated middle bench tumbles forward and provides just enough space to make entry and exit somewhat graceful.

When seated, rear occupants are treated to two USB-C ports and one small cupholder each, so they’re arguably taken better care of than those in the middle.

Child seats are well and truly accommodated, with four ISOFIX and five top-tether anchorage points fitted across the second and third rows, although the latter will inevitably prove to be a much tighter fit.

The driver and front passenger are still taken care of, with a front cubby taken up by two heated/cooled cupholders, a wireless smartphone charger, two USB-C ports and a 12V power outlet, while their door bins take one large and one small bottle each.

In-cabin storage options include the large central storage bin, which hides another USB-C port, while the glovebox is on the smaller side, with about a third of it taken up by the fragrance, which is pumped into the cabin to ensure the interior always smells its best.

Snug but spacious enough, the RS Q3 Sportback's driver and front passenger are provided with plenty of breathing room without upsetting the intimate, performance car feel. Just be prepared for a bit of head-ducking physical origami when folding yourself into either of the heavily bolstered front seats.

Storage includes door bins with room for bottles, two generous cupholders in the centre console, a lidded tray in front of the gearshift (which doubles as the wireless device charging bay), a storage compartment and owners manual holder under the front seats, a modest glove box and an adjustable front centre armrest with storage compartment.

Given this car measures just over 4.5m end-to-end, a close to 2.7m wheelbase is significant  and rear room is generous given the Q3's overall footprint. Plenty of head and legroom (for me at 183cm) with enough width for three adults on short journeys. A trio of up to teenage kids will be fine.

The back seat is able to slide for extra legroom (and slightly less boot space), while backrest angle is also adjustable.

Storage runs to small bins in the doors, a fold-down centre armrest (with two pop-up cupholders) and storage nets on the back of the front seats. Directional and temperature control in the rear for the ventilation system is a big plus.

Power and connectivity options run to a 12V outlet and two USB sockets in the front (Type A and C), another two Type C sockets in the back and a second 12-volt jack in the boot.

Speaking of which, cargo volume with all seats up is a handy 530 litres, enough to swallow CarsGuide's three-piece luggage set or large pram (the latter with room to spare) and 1400 litres with the 40/20/40 split-folding rear seat lowered.

The loading lip is low, a stainless steel sill protector helps minimise scuffs and scratches and the hands-free power tailgate is welcome.

If you're keen to hook up the boat or horse float the RS Q3 is able to tow a braked trailer up to 1900kg (750kg unbraked), but don't bother looking for a spare of any description, a repair/inflator kit is your only option. Boo...

The Audi RS Q3 Sportback edition 10 years is priced at $102,900, before on-road costs, which is a $3800 premium over the standard issue version.

For those extra dollars the car is upgraded with specific 21-inch black alloy rims, black badging and brake calipers as well as (three-stage heated) 'RS' Nappa leather-trimmed sports front seats with contrast 'Copper Honeycomb' stitching.

The fancy stitching extends to the Alcantara-trimmed steering wheel and gear lever, the RS floor mats also feature copper highlights and the door downlighting projects a unique rhombus design.

At that money the RS Q3 lines up against BMW's firecracker X3 M40i ($126,800), the ferocious Mercedes-AMG GLA45 S ($121,900) with the Jaguar E-Pace 300 Sport AWD ($84,500) the only other similarly pitched compact performance SUV within $20K of the Audi.

And as well as the performance and safety tech covered later in the review, the RS Q3's standard features list includes, three-zone climate control, adaptive cruise control, keyless entry and start, Nappa leather trim, ambient lighting (with 30 colour choices), an RS sport contour leather-trimmed steering wheel, 12.3-inch digital instrument cluster, 10.1-inch multimedia display (with text and voice control), (wired) Android Auto and Apple CarPlay, sat nav and wireless device charging.

There's also a Bang & Olufsen '3D Sound System' (15-speaker with 680-watt, 16-channel amp), digital radio, 21-inch alloys, electronically-controlled adaptive dampers, auto Matrix LED headlights (with RS-specific darkened trim) and a hands-free power tailgate. And it's worth noting metallic and pearl effect paint finishes are offered at no extra cost.

Pretty impressive. Especially when you consider even this special edition RS Q3 is $20,000 cheaper than its primary BMW and Merc-AMG rivals.

The GLS63 is powered by a familiar 4.0-litre twin-turbo V8 petrol engine, with its version producing a thumping 450kW of power at 5750rpm and 850Nm of torque from 2250-5000rpm.

This unit is mated to a nine-speed torque-converter automatic transmission and AMG’s fully variable 4Matic+ all-wheel-drive system with torque vectoring and a rear limited-slip differential.

This set-up also features Mercedes’ EQ Boost 48V mild-hybrid system, which actually gives a 16kW/250Nm electric boost in short bursts, such as when accelerating off the line.

Speaking of which, the GLS63 sprints from a standstill to 100km/h in just 4.2 seconds, while its top speed is electronically limited to 250km/h.
 

The RS Q3 Sportback is powered by a 2.5-litre in-line five-cylinder intercooled turbo-petrol engine sending drive to all four wheels via a seven-speed dual-clutch automatic transmission and Audi's quattro permanent all-wheel drive system based on an electronically-controlled multi-plate clutch pack.

Featuring a cast iron block, alloy head, direct-injection as well as variable intake and exhaust cam adjustment, the (EA855) engine features a special firing order (1-2-4-5-3), the odd number of cylinders producing a signature engine sound and exhaust note reminiscent of the 1980s 'Ur' Quattro.

Peak power is 294kW from 5850-7000rpm and maximum torque is 480Nm delivered across a broad plateau from 1950-5850rpm.

The GLS63’s fuel consumption on the combined-cycle test (ADR 81/02) is 13.0L per 100km, while its carbon dioxide emissions are 296 grams per km. All things considered, both claims are unsurprisingly high.

In our real-world testing, we averaged a fearsome 18.5L/100km over 65km of driving, split between highways and country roads, so not your usual mix. A very heavy right foot definitely influenced that result, but don’t expect to do too much better in a normal run.

For reference, the GLS63’s 90L fuel tank can be filled up with 98RON petrol at a minimum.

Audi's official fuel economy number for the RS Q3 on the combined cycle is 8.9L/100km, the 2.5-litre turbo-petrol five-cylinder engine emitting 204g/km of CO2 in the process. Stop-start is standard.

We covered city, suburban and some freeway running on test, returning an (indicated) average of 9.6L/100km. And that's pretty good, given we pushed on enthusiastically on a reasonably regular basis.

The fuel tank requires 63 litres of 98 RON premium unleaded to fill it which translates to a theoretical range of just over 700km, shrinking to around 650km based on our real-world number.

Frankly, the GLS63 has absolutely no right being as capable as it is. It’s a really big bus that’s legitimately convinced it’s a sports car half its size.

Being a GLS variant, the GLS63 has independent suspension consisting of four-link front and multi-link rear axles with air springs and adaptive dampers, but its party trick is the addition of active anti-roll bars.

In what feels like magic, the GLS63 is simply not intimidated by corners, despite having massive dimensions and a considerable 2555kg (kerb weight) to deal with.

The active anti-roll bars make the GLS63 so much easier to drive fast through the twisty stuff, almost eliminating body roll, taking one key variable out of the equation for the driver. Active engine mounts are also fitted, helping to settle things even further.

The electric power steering on hand is also good. It is speed-sensitive and has a variable ratio, which basically makes the set-up more direct when it needs to be. It’s typically light in hand, too, until one of the sportier drive modes is engaged and extra heft is added.

So, handling is scarcely believable, which means the ride must be compromised, right? Yes and no. With the adaptive dampers in their softest setting, the GLS63 is very compliant. In fact, we’d say it feels luxurious when compared to other high-performance SUVs.

That said, our test vehicle was fitted with the optional 23-inch alloy wheels ($3900), which look the part but expose sharp edges and other road imperfections, not to mention generate noise easily heard inside. Naturally, feedback is exacerbated in the sportier drive modes.

Anyway, there’s more performance, and the GLS63 has the rest in spades. Its engine is a powerhouse in every sense of the word. It’s so powerful, in fact, that it hilariously hunkers down off the line or when suddenly accelerating at low speed.

Thanks to the mild-hybrid system, wads of torque is available from the get-go, making for a highly responsive driving experience, even in those rare moments when the engine isn’t on song.

While not as characterful as some of the other members in the 63 series, the GLS63 still makes some thoroughly entertaining noises, with its sports exhaust system popping like mad while on the overrun.

All of this ability is very well and good, but you need to be able to pull up quickly, and the high-performance braking package (400mm front and 370mm rear discs with six-piston fixed callipers and single-pot floating stoppers respectively) mercifully does exactly that.

It still seems counterintuitive when a high-riding SUV is tuned to perform and handle like a low-slung sports car but here we are. And Audi executes this mystifying transformation as expertly as any carmaker in the automotive world.

Audi says the RS Q3 Sportback will blast from 0-100km/h in 4.5 seconds. Anything under 5.0 seconds is properly fast, and there's nothing quite like the deep-throated bellow of a VW Group in-line five to raise the hairs on the back of your neck.

The RS Q3's sport exhaust system is a dual-branch set-up with exhaust flap control, and people of a certain age will instantly imagine themselves matching it with Ari Vatanen, Walter Röhrl and Michèle Mouton on a suburban special stage behind the wheel of a 1980s Group B Sport Quattro rally car (actually, the school drop off at an infinitely more sensible pace).

The car weighs in at a not insubstantial 1775kg, but 480Nm, available all the way from 1950rpm to 5850rpm, means a near instant surge of fierce acceleration is always lurking under your right foot.

And the VW Group is on the pace when it comes to dual-clutch auto transmissions, from Porsche's 'PDK' and VW's 'DSG' to Lambo's 'DCT' and Audi's 'S tronic'.

The RS Q3's seven-speed unit is quick and positive, the wheel-mounted paddles ramping up the engagement factor.

The variable ratio, electrically-assisted steering is capital G Great. Well weighted and precise with reassuring road feel and the Alcantara trimmed wheel is a nice way to access it all.

Suspension is by struts at the front and multi-links (four) at the rear with adaptive dampers on-board.

Despite running on 21-inch rims, shod with high-performance 255/35 Continental PremiumContact 6 rubber, ride comfort is surprisingly good.

Dial in 'Comfort' mode via the 'Drive Select' system and the impact of even substantial bumps is softened off appreciably.

An ideal set-up would be the first 'RS1' short-cut Drive Select button set for Comfort suspension, with throttle, steering and transmission set to maximum attack and the second 'RS2' mode tweaking the suspension to track-day level, too.

Push on through your favourite set of bends and you can feel the electronic wheel-selective torque control system keeping everything under control. This car puts its power down through sweeping sections with fuss-free authority.

The RS-specific menu in the digital instrument cluster provides extra instrumentation in the shape of a power/torque display, G meter and lap timer. Fun!

The brakes are professional grade with big ventilated rotors all around and aluminium fixed calipers at the front.

But beware, the flip side of the RS Q3's quick steering response is a sizeable 11.8m turning circle. Take your time when parking.

Although the Audi Q3 received a maximum five-star ANCAP score in 2019, the RS Q3 was specifically excluded from the assessment, so it's officially untested.

But the car boasts an extensive active (crash-avoidance) safety suite including, auto emergency braking (AEB) (5.0km/h to 85km/h for pedestrians and cyclists and up to 250km/h for vehicles), adaptive cruise control (with stop-go function and active lane assist), lane change warning and lane departure warning (with lane keeping assist).

There's also 'Attention Assist' (warning tone and visual signal if the system determines the driver's attention may be lapsing), front and rear parking sensors, a reversing camera with 360-degree view, rear cross-traffic alert, tyre pressure monitoring, 'Hill hold assist' and hill descent control.

If, despite all that, a crash is unavoidable there are six airbags on-board (front and side for the driver and front passenger as well as full-length curtains). The RS Q3's showing its (10-year) age here because additional rear side and front centre bags are close to the norm now.

Nice to see a first aid kit and warning triangle included and there are three top tethers and two ISOFIX anchor points for securing baby capsules and child seats across the second row.

As with all Mercedes-AMG models, the GLS63 comes with a five-year/unlimited-kilometre warranty, which currently sets the standard for the premium market. It also comes with five years of roadside assistance.

The GLS63’s service intervals are relatively long, at every 12 months or 20,000km (whichever comes first). Better yet, it’s available with a five-year/100,000km capped-price servicing plan, but it costs $4450.

Audi Australia covers all the models it sells with a five-year/unlimited km warranty with 24-hour roadside assistance included for the duration. Pretty much cost-of-entry in this part of the market.

Paintwork defects are also covered for five years, and the body is warranted against corrosion (to the point of perforation) for no less than 12 years. Nice.

Service intervals are 12 months/15,000km and capped-price servicing is available, a five-year/75,000km plan for the RS Q3 costing $3580, an annual average of $770. Fairly steep.

An 'Audi Advantage' package is also available, adding an extra two years' worth of warranty, scheduled servicing and roadside assistance (to the end of any existing term) for $3800.