Mercedes GLB review

When it comes to SUVs, we’re spoilt for choice. There are small ones, big ones, rugged ones, fast ones, hybrids and even fully electric ones. So, where does that leave the Mercedes GLB?

Well, it’s actually one of few seven-seaters that you can buy with a premium badge – at least one that isn't the size of an aircraft carrier.

Underneath, it’s closely related to the Mercedes B-Class MPV. However, don’t let the ‘B’ in its name make you think that it’s small, because like its chief rival – the Land Rover Discovery Sport – it’s aimed at those who regularly carry lots of people or luggage.

We say "chief rival" because you could also be looking at the similarly priced Audi Q5 and the BMW X3 (although those are five-seaters only). If you can live without the premium badge but absolutely must have seven seats, there are other alternatives, including the Hyundai Santa Fe and the Peugeot 5008.

So, should the Mercedes GLB be at the top of your wish list, and how does it stack up against its key rivals? Read on to find out...

The Mercedes GLB's entry-level 1.3-litre mild-hybrid petrol engine – badged GLB 200 – has a seemingly healthy 161bhp. We've yet to try it, but it should be fine for pootling around town or when you’re by yourself.

There are two 2.0-litre diesel engine options – the 148bhp 200d and the 187bhp 220d. So far, we've tried the 220d, and its muscularity is a perfect fit for the GLB’s bus-like accommodation.

With an official 0-62mph time of 7.8 seconds, it's quite a bit quicker than a Land Rover Discovery Sport D200 and on a par with the BMW X3 20d. It pulls strongly between 1500rpm and 4000rpm and can tow a caravan without much difficulty. 

The most powerful engine in the GLB range is the 302bhp 2.0-litre turbocharged mild-hybrid petrol in the AMG 35. It can officially hit 0-62mph in just 5.5 seconds, aided by its standard-fit launch control system and four-wheel drive.

All engines come with an automatic gearbox – a seven-speed one in the 200 petrol, and an eight-speed with the other three. We've tested the eight-speed so far, and found it slow to react when you want to pull away briskly.

If you like the look of the GLB but want something that runs on electricity, check out our Mercedes EQB review.

This is one of the GLB’s weakest areas. Most versions jostle you around over uneven road surfaces, and tend to really thump over potholes, whereas the rival Discovery Sport is very comfortable, aside from a bit of float over undulations.

The AMG 35 comes with adaptive suspension, which you can soften or firm up on demand. It's wafty enough in Comfort mode, but really firm if you switch to Sport.

If you’re searching for outright fun behind the wheel, an Alfa Romeo Stelvio or BMW X3 would serve you better.

Still, the GLB has enough composure that it's not alarming to drive spiritedly, and the steering, while slow, is accurate and weights up with enough conviction to inspire confidence. There's more outright grip than a Discovery Sport generates. 

The lowered and stiffened AMG 35 disguises its height better than the standard GLB, but it's not as agile or as hunkered down as the best sports SUVs.

The diesels rumble away in most situations (not in an irritating way, but more so than an Audi Q5 40 TDI) but fade into the background at a cruise.

We expect the 200 petrol to be smoother, while the AMG 35 will be  deliberately noisier inside to add a bit more theatre, with an augmented engine sound piped through the speakers.

There's quite a bit of suspension noise in the GLB, and its door mirrors whip up wind noise at high speeds. Road noise on coarse surfaces is also fairly pronounced so, overall, if you like a bit of peace and quiet, you'll enjoy a Q5, X3 or Discovery Sport rather more.

Driving overview

Strengths Well-weighted steering; punchy diesel engines; GLB 35 AMG is very quick

Weaknesses Automatic gearboxes are slow to respond; underpowered entry-level petrol engine; too much wind and road noise

You’ll have no complaints about the amount of reach and height adjustment that you get with the steering wheel in the Mercedes GLB, or the amount of adjustment in the driver’s seat.

The entry-level Sport Executive and AMG Line Executive trims come with a manually adjustable driver’s seat with four-way lumbar support, while the top-level AMG Line Premium Plus trim brings extras on top, including full electric seat adjustment with a memory function.

In any trim, the GLB’s driver’s seat is narrow enough to make you question whether you’ll still fit if you eat dessert, plus some people will find the seats too firm. You sit comparatively low in the car, so you almost feel like you're in a hatchback rather than an SUV. The Land Rover Discovery Sport, by contrast, offers a wide, comfy seat and the sort of view usually reserved for HGV drivers.

All GLBs come with a 10.3in digital driver’s display instead of conventional dials, and you can arrange them in a number of modes and styles.

The rest of the dashboard layout works well, with a row of simple buttons to manage the climate control. It's a much better set-up than you get in the Discovery Sport (which buries the climate controls within the touchscreen) because it’s very easy to operate while driving.

The GLB's big, square windows provide a great view out of the front and to the sides, but over your shoulders there are blindspots behind each rear pillar.

You get a rear-view camera as standard to help mitigate those, along with front and rear parking sensors. To get blind-spot monitoring or a 360-degree camera, you’ll have to step up to AMG Line Premium or AMG Line Premium Plus respectively.

Every GLB gets LED lights all round, including the headlights. Top-spec AMG Line Premium Plus models have adaptive LED headlights, which you can leave on the main beam because they shape their light to avoid dazzling other road users.

As standard, you get a 10.3in infotainment screen with crisp graphics and responsive software. Built-in sat-nav, Bluetooth, DAB radio, and Android Auto and Apple CarPlay are all included as standard. Upgrading to AMG Line Executive adds wireless phone-charging.

Whatever the screen size, the screen is only operated using the touchscreen. That's a shame, because the GLB was previously available with a central touchpad controller (similar to a laptop’s), which made it slightly less distracting to operate while driving than prodding at the screen.

There are, however, two touch-sensitive pads on the steering wheel that you can use to control both the infotainment system or the digital driver’s display. Unfortunately they're quite fiddly to use, and it can be difficult to know whether you’ve made an input.

Alternatively, you can rely on the natural speech voice control for many things – you wake it up by calling out "Hey Mercedes!". Overall, the GLB's infotainment system is surpassed by the BMW X3’s.

Even without the atmosphere created by the ambient interior lighting in AMG Line Executive models, the GLB’s interior offers a clean and modern look. The most prominent areas, such as the top of the doors and dashboard, are upholstered in soft plastic or artificial leather, which helps give a premium feel. 

Just bear in mind that some of the materials used lower down are considerably less appealing than those in your eyeline, and the air-con panel flexes when you use it. The Audi Q5, the BMW X3 and the Land Rover Discovery Sport feel more tightly screwed together.

Interior overview

Strengths Smart dashboard design; physical climate controls easy to operate on the move; plush materials

Weaknesses Narrow front seats; fiddly touch-sensitive steering-wheel controls; build quality could be better

The boxy shape of the Mercedes GLB means there's lots of front space. Even the sunroof (which is standard on upper trims) doesn’t do much to dent head room, and leg room is copious, even for tall drivers and front passengers.

There's also plenty of space to store odds and ends. Pushing a button at the base of the centre armrest reveals a deep cubby, plus there’s another lidded cubby as well as two cupholders and a dedicated area for your smartphone on the centre console. Even the door pockets are big.

Six-footers will find they have plenty of leg room in the GLB’s second row. However, the Land Rover Discovery Sport offers more shoulder room for three people sitting side by side, and head room is also worse in the GLB, because Mercedes has mounted its second-row seats much higher than those in front.

The upside of this tiered approach is that kids get a better view forwards and out the side windows, so they might be less prone to car sickness. And like the Discovery Sport, most GLBs have two further seats that fold up from the boot floor, which is a benefit that the Audi Q5 and BMW X3 can't match.

As is the case with the Discovery Sport, you have to squeeze through a narrow gap to get to the GLB’s third row. And once there, you’re left in no doubt that you’re in the cheap seats, because your knees are pushed up high and there’s a lot less head room than there is in the first two rows.

However, smaller adults and teenagers will fit more comfortably than they do in the Discovery Sport because, unlike its rival, the GLB has room for your feet beneath the seats in front.

Every GLB has second row seats that can be slid back and forth to suit your needs.

And like the Discovery Sport, the three second-row seats each slide independently of one another in a 40/20/40 configuration. That gives you a great deal of flexibility, especially for carrying longer items.

Each of the seatbacks can also be reclined independently, while the third-row seats are very easy to fold.

Opening the tailgate reveals a fairly square cargo area with no lip at the entrance, making it easy to load and unload bulky objects.

With five seats in use, there's 500 litres of space up to the tonneau cover, which is enough for a couple of buggies or large suitcases, but not as much as an Audi Q5, BMW X3 or Land Rover Discovery Sport offer. If you have all seven seats in play, there’s space for a row of shopping bags, but that's about it. 

However, something that the GLB has that the Discovery Sport misses out on is a dedicated slot for the parcel shelf under the boot floor. That comes in handy when you suddenly have cause to deploy the third row of seats.

Practicality overview

Strengths Loads of interior storage space; flexible rear seating; square cargo area with low loading lip

Weaknesses Second row headroom could be better; third-row seats best suited for children; boot not as big as rivals in five-seat mode

Based on list prices, the entry-level Mercedes GLB undercuts its premium seven-seat rival, the Land Rover Discovery Sport, as well as posh five-seat SUVs, such as the Audi Q5, by quite some margin.

It’s even cheaper to buy than the Hyundai Santa Fe, and only marginally more expensive than the Peugeot 5008. However, those cars – especially the Santa Fe – are more spacious.

An upside of the GLB’s posh badge is that it depreciates quite slowly (although not as slowly as the Discovery Sport). And this helps its PCP finance deals look quite tempting when compared with those of some non-premium alternatives.

Our preferred engine – the 220d – compares favourably with the Discovery Sport D200 for official fuel economy. All the diesels are RDE2 compliant, which means there's no 4% diesel benefit-in-kind (BIK) tax surcharge to inflate company car tax.

Sport Executive is the entry-level trim but it still has all the basics, including 18in alloy wheels, dual-zone climate control and heated front seats, plus touchscreen infotainment and visibility aids.

AMG Line Executive adds a few extra goodies, including 19in alloy wheels, tinted rear windows, ambient interior lighting, a wireless phone-charging pad and sportier exterior styling. It’s the cheapest trim you can get with our favourite 220d engine, so it’s the one we’d go for. 

Next up is AMG Line Premium, which doesn’t bring a lot more to the table other than an augmented reality sat-nav, plus blind-spot monitoring and an upgraded sound system.

At the top of the range sits AMG Line Premium Plus, which comes with 20in alloy wheels, adaptive LED headlights, a panoramic sunroof and electrically adjustable front seats with memory settings. It’s the most generously equipped but it’s too pricey to recommend.

The GLB scored well in the 2023 What Car? Reliability Survey and ranked in fifth place for seven-seaters aged up to five years old, with a score of 90.9%.

That’s one place above the Discovery Sport (2017-present), which managed a score of 90.7%. In our reliability survey by brand, Mercedes finished in 24th place out of 32 brands. That’s not overly encouraging but it’s still ahead of Land Rover, which finished in 28th place.

In terms of warranty, you get three years with unlimited mileage, which is pretty much standard for the class. For added peace of mind, you also get Mercedes roadside assistance when driving in the UK and Europe. If you want the best warranty a seven-seat SUV can offer, the Kia Sorento has a seven-year warranty.

The GLB received five stars out of five for safety when it was appraised by Euro NCAP in 2019.

It's tricky to compare its score with newer rivals, though, because the GLB was tested a few years ago when the standards were more lenient. The GLB doesn't have any major issues, apart from a higher-than-average risk of adult chest injuries in a side impact. 

Useful safety aids, such as automatic emergency braking (AEB), lane-keep assist and attention assist, are standard on every GLB. If you want blind-spot monitoring, you’ll have to step up to AMG Line Premium.

Each third row seat has an Isofix point for the secure mounting of a child seat, as do the outer two seats on the second row. All GLBs come with a Thatcham-approved alarm and immobiliser too.

Costs overview

Strengths Competitive pricing; decent standard equipment; plenty of safety kit

Weaknesses Top trims are expensive; Mercedes as a brand ranks poorly for reliability

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