Mercedes-Benz GLS-Class vs BMW X Models

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…

If a BMW X3 is for you, then we have no quarrels with that. It’s a better all-round vehicle than the one it replaces and represents better value. And even though BMW mandates a hybrid driveline, there are still some significant choices within that framework.

By all means buy the M50 if you crave the rush of acceleration that almost 300kW can provide. And if efficiency is your altar of choice, then the plug-in 30e makes a lot of sense, too.

But even if you can afford either of those two more expensive variants, whatever you do, don’t dismiss the entry-level 20 model. At least drive it alongside the others and then make a decision based on all the facts, and not the assumption that entry-level equals the car you afford rather than the car you want.

It might be cheaper, but there’s absolutely no doubt that the 20 model is the one that shines and arguably makes the most of the opportunities BMW’s latest tech offers.

Sometimes less really is more.

Note: CarsGuide attended this event as a guest of the manufacturer, with accommodation and meals provided.

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.

It might be badged an X3, but this is no small vehicle. In fact, it’s bigger than the original BMW X5 (which set the tone for this entire market segment) with a length of 4755mm (4667mm for the first X5) and a width of 1920mm (1872mm). That said, it’s 25mm lower than the outgoing X3 in a move to emphasise its sportiness. Shorter it may be, but it’s also 16mm wider on the front track and 45mm wider on the rear than the outgoing model.

BMWs latest styling cues also appear in the new car, including the large, split-kidney grille that, for Australian-delivered cars, is also lit around its edges. The short overhangs that characterised the original X5 (and soon characterised this whole BMW genre) remain, and the T-graphic LED tail-lights round out the stylistic touches.

The other thing we noticed (and we’ve seen it on other cars recently) is a panoramic sunroof that doesn’t actually open.

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.

Cabin space is plentiful in the X3 with loads of room in the front, possibly thanks to the dashboard that is pulled back from you with only the twin screens and steering column offering themselves up to the driver. Even the air-vents are somewhat hidden. There’s good vision out and the seats themselves are lovely. The step into the cabin feels to be at just the right height, too; not too high, not too low.

Rear seating is good, too, although the X3 will always be better as a four seater than five thanks to the shape of the rear bench, but the glass roof opens the space up and there’s plenty of charging points and storage nooks. The sun blinds on the rear-side windows of the more expensive versions should be standard kit on every car sold in Australia.

We’ll take exception to the new gear-selector which doesn’t have a defined Park position and instead relies on applying the park-brake to engage Park. But the ambient light and contrasting cabin colours are a bit of a breath of fresh air.

There are levers in the cargo area to quickly fold the rear seats (60:40) at which point luggage space jumps from 570 litres in the mild hybrid cars to 1700 litres. The battery-pack of the 30e model means that luggage space starts at 460 litres and can be expanded to 1600 litres.

The latest version of BMW’s sometimes controversial iDrive operating system is simpler and easier to use than before and supported by a new operating system, but there’s still some familiarisation necessary. One improvement has been the addition of QuickSelect which works somewhat like the old favourites button system and gets around the need to drill into menus to access the functions you want.

A head-up display is a terrific addition, although where some displays are more tolerant of polarised sunglasses, the HUD in the BMW didn’t like mine and went dark at the most inconvenient angles.

None of the X3 variants feature a spare tyre of any sort. The 19-inch tyres on the base grade are run-flats, while everything else gets a repair kit for roadside emergencies.

If you want to tow, the good news is that all X3 variants can do so. But you will need to purchase the $2200 towing package which enables the X3 to haul a trailer weighing up to 2000kg with a maximum tow-ball down-weight of 200kg.

The new X3 range kicks off with three distinct models. There’s the entry-level 20 xDrive at $86,100, the 30e xDrive at $104,100 and the big-hitting M50 xDrive at $128,900, all before on-road costs.

Both the 20 xDrive and the M50 xDrive feature a 48-volt mild hybrid driveline, while the 30e xDrive goes all the way with a plug-in hybrid (PHEV) layout. All variants also feature BMW’s permanent all-wheel-drive system.

BMW claims greater standard equipment than ever before, and even the entry-level 20 xDrive has plenty of kit including 19-inch alloy wheels, tri-zone climate-control, the virtual cockpit screens with a curved central info screen, a six-speaker, 100-Watt stereo, acoustic glass, auto headlights, an auto tailgate, keyless entry and start, digital radio, powered and heated front seats, wireless Apple CarPlay and Android Auto and wireless phone charging.

The PHEV model adds 20-inch alloys, the M Sport package including blue brake calipers, and a leather steering wheel, as well as the Comfort Package which adds heated seats for the second row of outer seats, a roller sun-blind for each rear-side window, ventilated seats, a heated steering wheel, tinted glass and a luggage net. The 30e also gets parking assistant, a panoramic sunroof (a non-opening one), and a surround camera system.

Move up to the M50 variant, and you’re in for no-cost metallic paint, 21-inch alloys, a 15-speaker stereo, quad exhaust tips, M-specific details such as the mirror caps and aero add-ons. You also get a range of kit as standard that comes as an extra-cost option on the other two variants. Those include the enhancement pack that includes an alarm system, surround sound, M Sport Pro Package (various trim highlights, red brake calipers, M seat belts) and the Comfort Package that is also standard on the 30e.

The value headline is that, compared with the previous model, some variants of the new car are actually cheaper on an apples-with-apples basis. The base model car in its previous form was, by the time you added the now-standard M Sport package, dearer at $88,100, and the previous 30e optioned to include the standard kit the new car has, (heated rear seat, acoustic glass, roller blinds and more) was also (much) more expensive at $111,800. And although the M50 model in its previous guise was slightly cheaper at $126,800, it lacked the hybrid driveline, metallic paint and M Sport Pro package the new car has as standard.

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.
 

Hybrid tech across the board is the key phrase here, with the base-model 20 xDrive fitted with a mild hybrid electric motor and battery pack that works in conjunction with the 2.0-litre, turbocharged petrol four-cylinder engine. Power is 140kW and torque 310Nm. Like most mild hybrids, the electric motor offers power regeneration during braking, a mellow (by EV standards) kick in the pants during take-off and acceleration and also acts as the car’s starter motor.

The performance flagship, the M50 xDrive taps into the same technical philosophy with a mild hybrid augmenting the turbocharged six-cylinder inline petrol engine. In this case, however, peak power is a hefty 293kW and torque maxes out at 580Nm.

The most technically adventurous X3 is the 30e xDrive which uses plug-in hybrid tech to offer a claimed 91km of electric driving, about twice that offered by the original X3 PHEV it replaces. When the same 2.0-litre four-cylinder petrol as fitted to the 20 xDrive, and the electric motor are humming along together, there’s 220kW of power and 450Nm for the taking. The PHEV X3 can run in purely electric mode at up to a claimed 140km/h.

All variants use BMW’s familiar eight-speed automatic transmission and in each case, drive is sent to all four wheels on a permanent basis. Interestingly, the 30e and M50 versions package their electric motor as part of the engine-transmission combination. The 20, meanwhile, places its electric motor externally, as part of the drive-belt rotating assembly.

The M50 model has an M button that unleashes the full performance with one touch, and features an electronically locking rear differential in the interests of high-speed turn-in.

Adaptive suspension that varies the degree of damping is also part of the package on each X3 variant.

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.

As you might expect, the PHEV 30e model is the efficiency superstar of the X3 line-up with an official combined test figure of just 1.6 litres per 100km and 38 grams of CO2 per kilometre. The four-cylinder 20 xDrive is not bad for its size at 7.5L/100km (and 171g), yet the bruising six-cylinder M50 version with all that performance is not too far behind with an official figure of 8.2L/100km (187g).

The 30e PHEV features a selectable battery-saving mode as well as the option of forcing EV-only running. It features a 19.7kWh battery and BMW claims it can charge using a three-phase, 11kW socket from empty to full in two hours, 15 minutes. It does not make use of fast-chargers.

Exactly how far you’ll travel in the PHEV model will depend hugely on how and where you drive. On long, open road journeys, fuel consumption won’t be much different to the others, but with just a 50-litre fuel tank, it’s range won’t be stellar. But in urban running where the batteries are being recharged for free as you brake, the difference will be significant. Meanwhile, with a 65-litre fuel tank in the mild hybrid grades, the theoretical range (based on the official fuel number) is 865km and 765km for the 20 and M50 respectively.

While BMW recommends premium fuel for maximum efficiency, it also says that each X3 variant will not be harmed by the use of standard ULP if that’s all you can get hold of.

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.

Big heavy SUVS like this one haven’t always been too dainty on their feet. The extra bulk and height mean suspension has to be firmer, the big wheels and subsequent loss of tyre sidewall depth plays against ride quality and before you know it, the compromises have piled up and the driving experience has gone to hell.

This time, however, BMW’s claim that the X3 was designed from the start as an SUV and not converted from a sedan platform seems to hold water. There’s an overall greater sense of cohesion in the way the car steers and flows through corners and faster bends. The steering feel and feedback are a big part of that, too, and the whole seems at least as great as its parts.

The M50 is, predictably, a rocket with loads of accessible acceleration and a great noise while you’re enjoying it. That said, the 21-inch wheels and tyres don’t do anything for ride quality, but it remains an entertaining performance car in a familiar, ICE kind of way.

The plug-in is also perky with its 220kW on tap, but it’s less old-school and more techy. And while you can’t pick the point at which ICE hands over to electric and vice-versa, sensitive drivers will absolutely know that there’s a big dollop of electrical assistance when your right foot starts asking the tough questions. It definitely feels more overtly hybrid, though that shouldn’t be any kind of surprise, purely because that’s precisely the case.

Which brings us to the 20 entry-level grade. And while it’s going to be a controversial statement, this emerges as the most cohesive, rounded variant of the new X3. There’s something in the way the fizzy, bubbly (but very smooth) 2.0-litre four-cylinder provides more than enough urge, but never threatens to dominate the dynamics.

With less weight over the front wheels than the M50, and less weight overall than the PHEV, the 20 corners flatter, steers more intuitively and is simply more fun more of the time. Even on the optional 20-inch tyres, it rides better than the others, too, and might even be better again with the standard 19s other than the fact that those are run flats and we didn’t get try them.

The X3 – not too surprisingly – runs to all the latest driver assistance programs starting with autonomous emergency braking (AEB) that can identify pedestrians and cyclists. There’s also front collision warning, lane departure warning, parking assistant and a surround camera system. There’s also lane-keeping assistance which is calibrated perfectly and should be the standard for this type of otherwise intrusive technology.

You’ll also find front and rear cross-traffic warning, adaptive cruise control and tyre pressure monitoring.

The X3 hasn’t been ANCAP tested and there’s no real likelihood of that happening in the future.

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.

BMW’s warranty on the X3 is the company’s usual five-year/unlimited kilometre deal. But in this case, there’s also a six-year/100,000km warranty on the high-voltage battery.

Also typical for BMW is the service interval which is not a set time or distance and instead is determined by how the car has been used. It’s called condition-based servicing and it’s nothing new at BMW.

There’s also capped-price servicing available. For the X3, the five-year/80,000km service package is $2475.