Mercedes-Benz GLB-Class vs BMW X3

What's the difference?

It’s easy to say the GLB35 doesn’t deserve to be called an AMG when looking at its credentials on paper, but get behind the wheel and it’s evident Affalterbach played a key role in making it feel as special to drive as it should be.

The GLB35 has all of the great qualities of the GLB250 and other GLB variants, but successfully adds a performance focus to make for an even more compelling package.

Indeed, the GLB35 proves you can pretty much have it all.

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.

With the boxy and therefore rugged-looking GLB laying some great foundations, it’s no surprise the GLB35 looks pretty damn good – to these eyes, at least.

Being an AMG model, it stands out from the crowd with an aggressive body kit, with the chunky bumpers, aerodynamic roof spoiler and racy rear diffuser all unique alongside the now-signature Panamericana grille insert.

A set of 20-inch alloy wheels with 255/40 tyres ups the ante at the side, where the carryover black plastic wheel-arch and skirt cladding serves as an obligatory reminder that this is an SUV.

Also of note are the nicely designed LED headlights and tail-lights, which literally light the way, but there’s no getting past the bespoke diffuser element, which integrates the sports exhaust system’s dual 90mm tailpipes.

Inside, the GLB35 is a technological tour de force, with a pair of 10.25-inch high-resolution displays proudly sitting side by side atop the dashboard, with one the central touchscreen and the other the digital instrument cluster.

Both are powered by Mercedes-Benz’s MBUX multimedia system, which arguably remains the best there is today thanks its speed and breadth of functionality and input methods.

The GLB35 is also properly premium. Lugano leather upholstery covers the seats and armrests, while Nappa trims the sports steering wheel. Even the door shoulders and inserts get ‘cow hide’, although theirs is of the artificial variety.

Soft-touch materials are used for the upper dashboard, leaving hard plastics to the lower sections, which is what you’d expect for the price.

While the black headliner makes for a dark cabin, brightness comes from the metallic trim used throughout, notably on the steering wheel, dashboard, doors and centre console. And let’s not forget the pop of colour provided by the addictive ambient lighting.

And mercifully, scratch- and fingerprint-hungry gloss-black accents are limited to the surrounds of the turbine-style front air vents, dual-zone climate controls and centre console.

Unique to the GLB35 are Carbon Structure trim and stainless-steel sports pedals, just in case you forgot you weren’t driving a regular GLB.

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 4650mm long (with a 2829mm wheelbase), 1845mm wide and 1660mm tall, the GLB35 is more like the GLC43 in size than the GLA35, making it a mid-size SUV despite its small underpinnings. And that is good news for practicality.

Cargo capacity with the 50/50 split-fold third row stowed is more than solid, at 565 litres (VDA), but it can be increased to a cavernous 1800L with the 40/20/40 split-fold middle bench also not in use. If six or seven passengers are onboard, though, there’s very little room to move.

Nonetheless, the boot is still well packaged, featuring a huge aperture, no load lip, and a flat floor, which make loading and unloading bulkier items a hell of a lot easier. And even the load cover can be stored underfloor when out of action. How good.

There are also four tie-down points, two bag hooks, a side storage net and a 12V power outlet on hand to make matters even easier, while the rear seats can be stowed from the boot.

While we’re on the topic, Mercedes-Benz says the third row can accommodate passengers up to 168cm tall, with the middle bench able to slide fore and aft by up to 140mm.

Yes, I'm too tall, at 184cm, but I can still sit in the very back, although not in total comfort. All in all, about a centimetre of legroom and negligible headroom and toe-room are on offer there for me.

That said, getting in and out in the first place is the real challenge here, with the middle bench unable to tumble forward for easy ingress and egress. Yep, you’re not going to look smooth either way. Children can deal with it, but adults won’t be thrilled.

Therefore, the middle bench is the place to be, even when it’s slid all the way forward. Behind my driving position, it offers about a centimetre of legroom, but this can be increased to several inches by sliding it all the way back.

Either way, plenty of toe-room is available alongside more than an inch of headroom. The latter is more impressive when you consider that’s what you get with the standard dual-pane panoramic sunroof fitted.

Even better, the second row can seat three adults at a pinch, partly thanks to the low transmission tunnel, which means there’s the right amount of space for six fully grown feet across the two footwells. It goes without saying children will again be fine.

Speaking of which, four ISOFIX and five top-tether anchorage points are on hand for fitting up to four child seats across the second and third rows, which makes the GLB35 a serious option for families that like to be sporty.

There are plenty of in-cabin storage options, with the large central storage bin featuring a pair of USB-C ports, while the glovebox is also quite useful, even if it is oddly shaped. And there’s also a sunglasses holder in front of the rearview mirror.

The centre console’s cubby isn’t really designed for storage, with it basically taken up by two cupholders, another USB-C port and a wireless smartphone charger.

The front door bins can accommodate one small and two regular bottles each, which is great, while their rear counterparts can take one small and one regular apiece.

Second-row occupants also have access to a fold-down armrest with another pair of cupholders, but being of the retractable variety, they’re flimsy.

These passengers also have two USB-C ports, with the pair folding out below a small cubby and air vents, which are found at the back of the centre console. Storage nets are also fitted on the front seat backrests.

And don’t worry; the third row gets in on the action, with two cupholders (one regular, the other small) splitting the seats, which have individual USB-C ports and device straps to the sides.
 

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 GLB35 is powered by an uprated version of the GLB250’s 2.0-litre turbo-petrol four-cylinder petrol engine, with the AMG-fettled version producing a more substantial 225kW of power from 5800-6100rpm and 400Nm of torque from 3000-4000rpm (up from 165kW/350Nm).

This version is also matched to an eight-speed dual-clutch automatic transmission as well as Mercedes-AMG’s front-biased but fully variable 4Matic all-wheel-drive system.

Thanks to this combination, the GLB35 can sprint from 0-100km/h in just 5.2 seconds with launch control enabled, while its electronically limited top speed is 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 GLB35’s fuel consumption on the combined-cycle test (ADR 81/02) is 8.3L per 100km, while its carbon dioxide emissions are 186 grams per km. All things considered, both claims are pretty decent.

In our real-world testing, though, we averaged a high 14.1L/100km over 75km of driving split between highways and country roads, so not your typical mix, then. A heavy right foot also played into that result, so expect a better return after a regular run.

For reference, the GLB35’s 60L fuel tank can be filled up with 98RON petrol at 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.

Don’t let the GLB35’s family friendliness fool you, this is an SUV that can get up and go.

The engine’s extra power and torque over the GLB250 are immediately felt behind the wheel, with the GLB35 accelerating with the vigour of an all-wheel-drive hot hatch, which makes sense given their similar claims.

And if you have one of the sportier drive modes engaged, the booming noise generated is also special – even if a lot of it is of the artificial variety, pumped into the cabin to make occupants feel like things are getting serious.

What is genuine, though, is the well-rounded transmission, which is characteristically quick with its upshifts. At the same time, it’s also relatively smooth, even at low speed, which has proven to be a challenge for dual-clutch units over time, but not here.

To earn the AMG badge, the GLB35 goes even further with other mechanical upgrades, including sports tunes for the suspension and steering.

Specifically, the GLB35’s independent suspension set-up not only consists of MacPherson-strut front and trailing-link rear axles with adaptive dampers, but also introduces new steering knuckles, transverse control arms on the front axle, and a stiffened subframe.

The resulting ride is actually quite good. Yes, the extra firmness over the GLB250 is noticeable – particularly in the sportier drive modes that stiffen the adaptive dampers all the way – but it’s by no means a deal-breaker.

That said, it’s worth noting our test vehicle was fitted with the optional 21-inch alloy wheels ($1990), so the GLB35’s like to ride even better on its standard package.

This is remarkable considering the handling improvements made, with the GLB35 managing body roll and pitch better than the GLB250 when pushing hard into and around corners, coming out of which grip is plentiful thanks to the all-wheel-drive system.

Thankfully, the standard-fit high-performance braking package consisting of 350mm front and 330mm rear discs with four- and one-piston callipers respectively helped it wash speed away with ease when attacking the twisty stuff with intent, even with 1857kg (kerb) to deal with.

Also on hand is electric power steering, which is speed-sensitive and has a variable ratio in the GLB35. Basically, it’s quicker when you want it to be, remaining on the lighter side in hand until you engage one of the sportier drive modes and weight is increased markedly.

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 GLB35 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 GLB35’s service intervals are long, at every 12 months or 25,000km (whichever comes first). Better yet, it’s available with a three-year/75,000km capped-price servicing plan, but it costs $2750, with the third visit alone incurring a $1300 charge.

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.