BMW X3 vs Mercedes-Benz GLB-Class

What's the difference?

This is a highly competent all-rounder, given that it has the comfort and practicality for urban family duties yet with its revered M breeding can produce a level of performance which, in competent hands, could hold its own at a track day where its capabilities could be safely explored.

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.

The fourth-gen X3, which has a lighter but stiffer body, shares the same wheelbase as its third-gen predecessor but at 4755mm end-to-end it's 34mm longer and it's 29mm wider.

It’s also 25mm lower, which combined with front and rear track-width increases and adaptive suspension damping to sharpen the handling underlines its sportiness and driver appeal, despite a substantial 2055kg kerb weight.

The new exterior design is characterised by short overhangs, flush door handles, a larger ‘split kidney’ grille, new LED taillights and L-shaped light elements for the LED headlights.

The new interior design is a classy mix of soft-touch materials and high-gloss hard surfaces in tastefully contrasting tones. The seats are upholstered in a new synthetic leather called 'Veganza' ('Espresso Brown' in our example) which according to BMW requires 85 per cent fewer CO2 emissions to produce than genuine leather (which is still available as an extra-cost option).

Combined with subtle use of ‘Magnolia’ fine-wood trim inserts, satin chrome, piano black, blue/red M highlights and slender ambient light-strips, it’s a cabin that exudes opulence.

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.

This would make a great family weekend escape machine, for which BMW quotes a 645kg payload rating. It’s also rated to tow up to 2500kg of braked trailer, which could pose a challenge given the relatively low 100kg tow-ball download limit (TBD is typically around 10 per cent of trailer weight).

BMW also does not publish a GCM figure (how much it can legally carry and tow at the same time) so we can’t confirm if it can carry its maximum payload while towing its maximum trailer weight.

Even so, the M50 has a useful-sized luggage area which offers up to 570 litres (or 0.57 cubic metres) of load volume with the rear seat upright.

This expands to 1700 litres (or 1.7 cubic metres) with the rear seat folded flat, which can be handy for a multitude of tasks like transporting a mountain bike or hauling home flat-pack furniture.

There’s comfortable space for the driver and front passenger, along with useful storage including large bottle-holders and bins in each front door.

The centre console has two small-bottle/cupholders plus wireless phone-charging and a pair of USB ports. There's also a glove box plus another box at the rear of the console with a padded lid that doubles as an elbow rest.

The rear bench seat is surprisingly spacious, given that I’m 186cm tall and when seated behind the driver’s seat in my position I still have about 40mm of knee clearance, which is optimised by the concave shape of the front seat backrests.

The spacious and airy feel is enhanced by the ‘panorama’ glass roof which spans the full length of the seating area and allows generous headroom even for tall people.  

However, shoulder room is tight for three adults and the centre passenger’s feet must contend with the transmission tunnel, so even though it would be fine for three kids we’d suggest a limit of two adults for longer trips.

Rear passengers get privacy glass and pull-up roller sunshades, large-bottle holders and bins in each door plus net-type pockets and anchorage points for media devices on each front seat backrest. There are also two small-bottle/cupholders in the fold-down centre armrest.

The rear of the centre console has two USB ports, adjustable air-vents plus controls for zone temperature, airflow preferences and seat-heating.

The bench seat features a 40/20/40 split, which allows the centre backrest to fold forward independent of the two outer backrests to allow long loads like snow skis, home hardware etc to be carried if securely fastened.

A power tailgate provides access to the luggage area, which is equipped with a handy 12-volt accessory socket plus load-anchorage points front and rear, extra storage nooks for small items on either side and a retractable roller-type load cover. Overall, this vehicle offers good practicality for family duties.

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).

According to BMW, the M50 xDrive features the most powerful inline six-cylinder petrol engine fitted to an M Performance model.

This 3.0-litre unit clearly benefits from BMW’s twin-scroll turbocharging technology, which combined with variable valve timing and an extra 13kW/200Nm from the 48V mild-hybrid technology produces a stomping 293kW of power at 5500rpm and 580Nm of torque at 1900rpm.

It also has a ‘boost’ function, which provides an extra burst of power for short periods when maximum acceleration is required when overtaking etc.

It’s activated by the left paddle-shifter on the steering wheel and automatically optimises transmission/chassis settings to suit. There’s also a drive mode selector, with ‘Sport’ offering the most responsive and engaging experience.

The eight-speed torque converter automatic is a refined and efficient transmission well suited to this full-time all-wheel drive application. Rapid-fire manual shifting is also available using the steering wheel paddles.

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.

BMW claims an official average combined consumption of 8.2L/100km but the dash display was showing 9.9 at the completion of our 210km test, which included a mix of suburban, city and highway travel.

Our own figure, calculated from fuel bowser and tripmeter readings, came in slightly higher again at 10.5L/100km, which given our test vehicle’s two-tonne-plus weight and performance capabilities is still reasonable economy.

So, based on our figures, you could expect a realistic driving range of around 600km from its 65-litre tank, which prefers premium 98 RON petrol.

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.

First, the fun stuff. It certainly feels like ‘the ultimate driving machine’ when you slide behind the chunky leather-rimmed flat-bottom steering wheel and hold it in your hands.

The driver’s seat offers not only powered adjustment of backrest and base-cushion rake, but also four-way lumbar support and side-bolsters that can tighten their embrace of your upper torso to contend with high cornering loads.

There’s also manual extension of the base-cushion length for greater thigh support and a big left footrest to brace against, so you could not ask for a more accommodating and purposeful driving position.

The steering is perfectly weighted and the quartet of enormous disc brakes provide ample bite with superb pedal feel. Combined with its adaptive suspension and wide grippy tyres, the X3 is a family car that’s also invigorating to drive, particularly when you select the ‘Sport’ mode.

The enhanced engine response and sharper steering that result (even the instrument panel display changes) make any twisting mountain road an engaging experience, enhanced by an intoxicating exhaust note that only a BMW M six can deliver.

The turbocharged engine offers an unyielding surge of acceleration from well below peak torque at 1900rpm to maximum power at 5500rpm, making BMW’s claim of 0-100km/h in a scant 4.6 seconds sound credible.

You can also manually change gears using the steering wheel paddles, but we found the gearing and shift calibrations so good that we preferred to leave it in auto mode.

However, the X3 M50 has two distinct personalities, as in more relaxed drive modes it’s just as happy serving as practical family transport during the week for grocery shopping, daily school runs and other common tasks.

It’s also a comfortable tourer for family getaways, with long gearing that requires only 1500rpm to cruise at 100km/h where low engine, tyre and wind noise allow highway conversations at lounge room levels.

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.

It comes standard with a five-year, unlimited km warranty.

Scheduled servicing is determined by BMW’s vehicle monitoring system which advises when a service is needed, typically around 12 months/15,000km.

A capped-price servicing package covering five years/80,000km (whichever occurs first) totals $2475, or an average of $495 per service.

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.