Mercedes-Benz GLS-Class vs BMW X6

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…

I was not expecting to like the BMW X6 xDrive 40i M Sport as much as I do. The styling is still polarising but the facelift will throw more people towards the liking rather than disliking side of the fence. The cabin and boot are super practical and the X6 nails all the premium elements you expect at this level. It’s driving and handling are what win me over, though.

My son loves this one and doesn’t want to hand it back. My husband also noted how nice he thought the X6 was… and that’s saying something for a born and raised 'country boy'!

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.

SUV coupe styling with its raised platform and pinched bum just doesn’t do it for me usually but I like it on the new X6 model. The facelift helps the X6 appear more athletic and just plain meaner than the previous version.

The front end sees the most change with new adaptive LED headlights and a bigger 'kidney' grille. The kidneys are illuminated, which adds to its night-time presence and the extended blacked-out intake vents at the front and around the car make it look sharp as hell.

The weird prong on the side mirrors has been dropped in favour of a more seamless design (hurrah) and the 22-inch alloy wheels give total va-va-vroom sport-vibes. 

On the interior, the dashboard has been revamped with a more pronounced shape and a curved display panel that houses the 12.3-inch digital instrument cluster and 14.8-inch multimedia system.

The air-vents now blend more into the dash but the little knobs for them might not be everyone’s cup of tea.

The ambient lighting is customisable and the quilted seats look beautiful but purists will wince on learning it’s synthetic leather, especially at this price point, but it feels and looks very nice. 

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.

You know you’re in a large SUV when you slide into the X6 because the cabin has a lot of space in both rows.

But also because of the higher centre console design, you feel tucked into the car despite the higher seating position. It makes it feel far sportier than your typical SUV. 

Even back rowers enjoy decent legroom and headroom, despite the panoramic sunroof and sloping roof design. Six-footers should be relatively comfortable in both rows but it's best to reserve the middle seat as a sometimes position for adults. The raised floor won’t allow true comfort for a longer trip.

Let’s chat luxury because there’s plenty to be had with the electric front seats and their cloud-like comfort.

The electrically-adjustable side bolsters and adjustable lumbar support makes it feel like you’re being cuddled by the seat and also hold you in place in a turn. The extendable under-thigh supports minimise leg fatigue on a longer trip.

However, the back seat is almost as comfortable as the fronts in terms of cushioning. You also sit in, rather than on top of the seats which is a nice change for an SUV. 

Individual storage is great in both rows and up front you get a dual-opening middle console, glove box and a handy utility area that houses the cupholders and two phone pockets.

There is also a storage nook on the driver’s side that will comfortably hold a wallet. 

In the rear you enjoy two map pockets on the front seat backs and retractable cupholders in the fold-down armrest.

The armrest houses a shallow device holder and sits at a good height. Both rows enjoy deep storage bins in each door and a large drink bottle holder.

Happily, the holder is tilted towards the user, rather than away which is what you usually see.

The boot is a great size at 580L with all seats in use. There’s a little lip that has practical metal scuff plates but otherwise the loading space is level.

The hands-free powered tailgate is welcome and the handy 40/20/40 split on the back row opens up your storage options.

You get a temporary spare tyre underneath the floor and it’s cool how the floor has a gas strut, which makes the area much easier to access.

The concertina-style cargo cover is a bit dicky to use but I like how solid it is. It could easily double as a shelf by itself. 

Charging options are abundant with a total of two 12-volt ports, a USB-A port, three USB-C ports and a wireless charging pad to choose from throughout the car. But it is annoying to use the pad when the front cupholders are in use.

I like having hardened kickplates on the backs of the front seats because my seven-year old loves putting his feet on everything.

The higher ground clearance makes this an easy car to get in and out of but it also makes for a great view for my son. He finds the doors a little heavy to close but the massive door grab handles help!

Amenities in the rear row make it a pleasant space to be in for kids and adults alike. You have reading lights, map pockets, two storage shelves and directional air vents.

There is manual climate control in this row, too, but it feels at odds with the rest of the high tech in the car.

On that note, the updated technology looks gorgeous.

The head-up display is clear and the digital instrument panel offers plenty of customisation. It's a super handy feature to access your recent call log via the steering wheel controls and see it pop up on the instrument cluster. 

The touchscreen multimedia system is responsive but you can also use the rotary dial to get around it. There is a stack of information in it, though, which will take a bit to get your head around. Can’t fault its graphics, it looks hot, but some users may feel flustered at first.

The system has built-in satellite navigation that features an augmented reality feature, which overlays dynamic instructions on the video feed. What makes it practical is how it can be viewed on your instrument cluster, which means more on-road focus for the driver. 

There is wired Android Auto and wireless Apple CarPlay, with the latter being simple to connect to. You don’t have the important climate control buttons/dials up front and I find it annoying to access the multimedia screen to change climate and fan speed settings. 

What you lack in controls there is more than made up for in the centre console. There are a lot of buttons, from the push-button starter, rotary control wheel and everything in between.

Even after a week, my mind still has a mini freeze looking at them while on the go.

There are three variants for the X6 before you jump up to the performance M grade. Our test vehicle is the mid-spec xDrive40i M Sport model and will cost you $144,900 before on road costs.

That places it in the middle of its rivals and you get a well-specified model for the price tag but our test vehicle has also been fitted with a few extras, like the 'M Sport Package Pro' which adds a darkened grille and accents throughout the car, an M Sport exhaust system, red M Sport brake calipers and the M Sport signature colour stitching in the seat belts. All of that adds $2308.

Our test model also has the 'Enhancement Package' which tacks on $4616 but you get some great items like the crystal glass accents on the rotary dial and push-start button and a premium Harman Kardon surround sound system.

It also adds big 22-inch alloy wheels, a tyre pressure monitoring system and a temporary spare tyre which replaces the standard run-flat tyres on the base model.

Oh, and the 'M Brooklyn Grey Metallic' paintwork adds $1539. Just sayin’ it will cost you a pretty penny but it’s not outrageous for a luxury SUV.

Other standard equipment includes synthetic leather trims, electric front seats with heat function, electrically adjustable steering wheel, sports paddle shifters, M Sport styled scuff plates and badging, exterior puddle lamps and a full suite of LED lights including adaptive headlights. 

You also enjoy a panoramic sunroof, adjustable lumbar support on both front seats, as well as extendable under-thigh support.

The drivers seat features two memory positions and comfort entry/exit functions (the seat and steering wheel slide back for you to get in and out of car).

For practicality, there is a hands-free powered tailgate, pre-entry climate control with programable entry time and a boot floor that features a gas strut for easy access.

We’ll touch on the tech later but the highlight is a new curved display panel that houses the 12.3-inch digital instrument screen and 14.8-inch touchscreen multimedia system. 

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 xDrive40i M Sport has a 3.0-litre, inline six-cylinder turbo-petrol engine with maximum outputs of 280kW and 540Nm. That’s 30kW and 90Nm up from the previous model.

It has a smooth eight-speed auto transmission and is all-wheel-drive.

The facelift sees the addition of a new mild-hybrid system which makes for almost imperceptible stop/start functionality when idling and a smidge better on-road fuel economy. 

With a 0-100kmh sprint time of 5.4-seconds, it’s obvious that it has plenty of power to have fun with.

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.

Expectations for a thirsty engine were high, considering the hefty power available, but this version of the X6 has proved to be quite economical.

The xDrive40i M Sport variant has an official combined cycle fuel economy figure of 9.3L/100km but my real-world usage averaged 8.8L/100km.

That’s after mostly open-road driving with only a little ‘city’ thrown in but I didn't hesitate to use the power, so I'm happy with the result.

The X6 has a big 83-litre fuel tank and based on my usage, you’d see a driving range of around 943km, which is great.

BMW only recommends a minimum 95 RON petrol to be used.

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.

The X6 is a thoroughbred on the road. It’s wide stance and massive wheels provide a well-balanced and grippy on-road ride experience.

Seriously, the tyres feel glued to the road even in the wet. Confidence is high with this one.

There is plenty of power to enjoy and you don’t feel like you’re digging deep for it, either, when you have to get up to speed or overtake.

It has the handling and power of a much smaller and sportier car but at no point does it feel wild or reckless to drive. It’s got a certain elegance and maturity to its handling.

Despite those massive wheels, the ride comfort is fantastic with the adaptive suspension. You still feel the road but you’re not knocked about by it. It’s very much a driver’s car in that sense but passengers still feel well-cushioned.  

The cabin is insulated and you get basically no road noise or wind noise but occasionally you get some feedback from the tyres depending on the road surface. Longer journeys are comfortable and quiet.

The steering is light enough that you don’t feel like you’re hauling a massive SUV around but is still responsive. Meaning you can tackle a winding road or urban traffic easily.

When it comes time to park it, you’ll love having the 360-degree view camera system. It’s the best and clearest system I’ve sampled.

Add the front and rear parking sensors and no car space is an issue. But if you’re unsure, you can use the Park Assist feature to help out.    

The X6 has an extensive safety list and I like the SOS emergency call button and front cross-traffic alert. Both are great to have but the latter is particularly useful on a large SUV like this, especially in the city or driveways.

Other standard safety equipment includes blind-spot monitoring, autonomous emergency braking, LED daytime running lights, forward collision warning, side collision warning, rear cross-traffic alert, lane keeping aids, lane departure warning, intelligent seat belt reminders, front and rear parking sensors, 360-degree view reversing camera, traffic sign recognition, driver fatigue monitor, and adaptive cruise control with stop and go functionality. As well as an SOS emergency call button and stolen vehicle tracking.

The X6 hasn’t been tested by ANCAP, so it’s unrated but it is based on the X5, which achieved a five-star rating in 2018. However, it only features six airbags which is low for a family car.

There are ISOFIX child seat mounts on the outboard seats and three top tethers in this row. Two seats will fit best but I reckon you could squeeze a third in if you had to.

There’s plenty of room for front passengers when you install a 0-4 rearward facing child seat, too, which is good.

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.

The ongoing costs are surprisingly reasonable for a large luxury SUV! Like its rivals the X6 enjoys a five-year/unlimited km warranty.

However, you can pre-purchase a servicing plan for up to five years or 80,000km, whichever occurs first, for a flat $2400. Or an average of $480 per service which is inexpensive for this class.

Service intervals are also good at every 12 months or 15,000km, whichever occurs first.