BMW X4 vs Mercedes-Benz GLB-Class

What's the difference?

Okay, so the BMW X4 xDrive30i is neither an ass nor an elbow, to be fair, it's more of a bulky shoulder muscle, or two.

I can't say I'll ever love the X4, the idea of it is a bit too weird for me, but I can't help admiring the way it looks and the way it drives.

It's a bit like a sedan on steroids - or an SUV on a diet, depending on your perspective - but that doesn’t take away from the fact that it’s fun to drive, comfortable and retains just enough coolness, and just enough practicality, to make it worthwhile.

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.

So here's the thing. Obviously I have a personal beef with the existence of vehicles like this, but my eyes cannot deny the facts - the X4 looks fantastic. It's muscular, imposing and smooth all at once. Unlike the X6, a bigger and less visually successful attempt to play the same styling tricks with an X5, it doesn't have a ridiculous rear view that looks like it shoulders and buttocks have been fused (although it's hard to miss just how small the rear window is).

Even more impressively, there's no denying it looks better than the X3 that gave birth to it, so I can easily see why someone in a BMW showroom could be drawn to it. At least until they sit inside.

If the exterior style and eye-catching Sophisto Grey metallic paint don’t make an immediate impression then your eyes will surely widen at the interior, resplendent with bold Tacora Red seats, Aluminium Rhombicle trim finisher and the kind of sleek, classy styling that BMW excels in. 

Both the adjustable ambient lighting on the doors (we were partial to lilac) and door projectors that shot out what looked like robot wings onto the ground every time we hopped out of the X4 at night walked a fine line between futuristic cool and “parked out the front of a nightclub entrance” chintz, but over time the scales tipped more to the former. 

The big differentiator between the X4 and X3, of course, is the sloped coupé roof, a design feature that may make the X4 look a little cooler, but at the expense of cabin space, but more of that in a moment.

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.

For a car that is very much a mid-sized SUV on the outside, the interior can feel a bit too snug, like you’re driving a compact car that’s tried on a suit a few sizes too big (for reference, I’m 175cm tall - above-average height drivers may find the snugness soon turns to claustrophobia). 

While comfortable - it is BMW we’re talking about, after all - there’s not an overly abundant amount of headroom available, a feeling that becomes more pronounced should you shut the big moon roof.

My two children felt slightly too close to “you’re annoying me” distance from one another, which is to say this isn’t really the kind of car you should be getting if you plan on regularly ferrying about passengers in the rear who are bigger than a child. But I really don't think many people with kids would choose the X4 over the X3.

Boot space also takes a hit when compared to the X3 (550 litres versus 525-litres in the X4 - I was surprised the difference wasn't larger - although that expands to 1430-litres with the rear seats folded down. 

The boot opening is also mouth-shaped, which makes packing in wide-load items more of an issue.

Cupholders are plentiful - two in the front, two in the rear, and bottle holders in each door - and there’s a decent-sized storage cubby in between the front two seats. 

The sloped roof, and big fat A pillars, also result in the X4 being a bit more pinched at the rear, which is not especially great for visibility, with the vehicle’s blind spots taking some getting used to.

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.
 

Priced from $88,535 plus on-road costs, the GLC35 currently sits atop the GLB range, above both the $59,900 GLB200 and $73,535 GLB250.

Standard equipment not already mentioned in the GLB35 includes dusk-sensing lights, rain-sensing wipers, power-folding side mirrors, black roof rails, rear privacy glass and a power-operated tailgate.

Inside, satellite navigation with live traffic, Apple CarPlay and Android Auto support, digital radio, a 225W sound system with nine speakers, keyless entry and start, power-adjustable front comfort sports seats with heating and memory functionality, auto-dimming mirrors, illuminated ‘AMG’ scuff plates and ‘AMG’ floor mats feature.

As is commonplace for Mercedes-Benz models, the GLB35 has plenty of options with most expensive, so you could drive away with a vehicle that’s dearer than you originally thought.

But aside from a spare wheel and some safety equipment we’ll cover in a moment, the GLB35 doesn’t leave much to be desired, which is always a good thing.

Nonetheless, our test vehicle was finished in $1490 Iridium Silver Metallic paintwork, which is one of eight extra-cost exterior colour options.

As mentioned, the GLB250 is a unique proposition, so it’s only comparable rival, the more affordable but less sporty Land Rover Discovery Sport P250 HSE ($78,432).

Now, prepare to be confused. In the past, the 3.0 in the xDrive3.0i nomenclature might have led you to believe you'd bought a BMW with a 3.0-litre straight six engine. But in this case, you have not, the 3.0 just means you have a more exciting version of the 2.0; a TwinPower turbo 2.0-litre inline four-cylinder engine, making 179kW and 353Nm that the xDrive system delivers to all four wheels. 

The claimed zero to 100km/h time of 4.9 seconds feels completely realistic as this engine has plenty of poke. Put it in the Sport setting and you'll get some serious shove. Indeed, the switch between Comfort and Sport is very noticeable and changes the character of the car entirely.

The transmission is an eight-speed conventional torque converter automatic gearbox that’s both smooth and responsive. 

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.

The X4’s 65-litre tank needs to be 95-octane at a minimum, and BMW’s claimed combined fuel consumption is 7.9 litres per 100km. The temptation to use its rorty little engine is going to push you higher, though - you chose the one with the 3.0 badge on it after all - and we averaged 10.9 litres per 100km in our week together, which was mainly city driving, to be fair. 

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.

The impressive trick that BMW continually pulls off with its SUVs is giving them the same sensual, muscular steering as its sedans, and an impressively similar ride and handling balance.

The steering is the highlight here, but it's also noticeable how planted to the road it feels.

The X4 speaks to its looks, in fact, by feeling sportier and more alive to drive than you'd expect an X3 to be.  

This is less an SUV for soccer mums and dads, and more a bastard love-child that’s into loud leather and bright neon - a CEO who dressed punk rock-lite on weekends, if you will. 

If those weekends are bereft of child taxiing and loading up the boot with several tons of kid stuff, then you’ll have a blast in the X4. 

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.

ANCAP awarded the GLB range its maximum five-star safety rating in 2019.

Advanced driver-assist systems in the GLB35 extend to autonomous emergency braking (AEB) with pedestrian and cyclist detection, lane-keep assist, blind-spot monitoring, rear cross-traffic alert, traffic sign recognition, driver attention alert, tyre pressure monitoring, hill-descent control, hill-start assist, park assist, a reversing camera and front and rear parking sensors.

Is anything missing? Well, steering assist, adaptive cruise control, active blind-spot monitoring and front cross-traffic alert form the optional Driving Assistance Package ($1990), which definitely should be standard at this price point.

And let’s not forget the two other noticeable absentees: surround-view cameras and high-beam assist. They’re annoyingly part of the optional Vision Package ($1190), which was fitted to our test vehicle.

Nonetheless, other standard safety equipment includes nine airbags (dual front, front-side, curtain and rear-side plus driver’s knee), anti-skid brakes (ABS), electronic brake-force distribution (EBD) and the usual electronic stability and traction control systems.

Despite all the brouhaha about other car manufacturers offering more generous warranty periods - seven years for Kia, for example - BMW has not shifted its stance, still offering its standard three-year unlimited-kilometre warranty. Frankly, it's just not good enough.

BMW also offer a Service Inclusive package for $2010 that covers owners for five years, or 80,000km.

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.