Mercedes GLB Review

Mercedes has squeezed and stretched the A-Class's platform to fit a surprisingly wide selection of different compact models. Everything from the CLA four-door coupe to the GLA SUV can trace its bones back to the brand's entry-level hatch.

The GLB is one of the more compelling collections of Mercedes parts, however. Here, the chassis is stretched all the way out, allowing for seven seats within its boxy body. Of course, that means the GLB is a reasonably large and chunky car, but it's nowhere near as gargantuan as the GLE or GLS seven-seaters that sit above it.

As a result, it only needs the same turbo four-cylinder engines as the A-Class to get around compared to its gas-guzzling bigger siblings. That means decent performance and strong fuel economy at a much more manageable price point than bigger seven-seat Mercedes models.

Inside, there's lots of the same technology and switchgear as other A-Class-based models, but Mercedes has given you a loftier driving position that fits with the GLB's SUV identity. In the back, you'll find controls to slide and recline the second row of seats, allowing you to make the most of the car's family-friendly practicality. However, actually using all seven seats at the same time proves more of a challenge, as we'll explain below.

It's also tricky to commend the GLB's value for money. There are similarly practical cars available for less money like the SEAT Tarraco, Skoda Kodiaq and BMW 2 Series Gran Tourer, along with models like the Land Rover Discovery Sport, which has a similarly premium image. That said, the GLB still feels worth the money it's charging  with plenty of leather and metal trim to help it feel more plush.

Most of the hardware in front of your eyes in the GLB is borrowed from the A-Class family of models. The steering wheel, air vents, climate controls and dash-top-mounted twin screens are essentially identical to the smaller hatchback.

The GLB's centre console is a little chunkier than its siblings, and there are some upright aluminium-effect trim pieces that are supposed to recall the larger G-Class off-roader. Generally, the most noticeable difference between sitting in the A-Class and the GLB, however, is the driving position itself, which is higher off the ground and gives you great visibility out the car's tall windows.

Unquestionably, the car's interior experience looks like something you'd expect from Mercedes but it doesn't always feel like one. Certain trim pieces further from reach can creak or groan if you put your weight through them to adjust yourself. To be clear, the car doesn't feel rickety and there are no audible issues when going over road bumps, but it's not quite the 'hewn-from-granite' sensation older Mercedes models managed to project.

The infotainment software, too, is shared widely around the Mercedes range. All the important functions like telephony, Apple CarPlay and Android Auto are present and correct and, once you've got them set to your liking, you'll have few complaints about the GLB's screen setup.

Entry-level AMG Line cars make do with a pair of small seven-inch screens for the driver and dashboard but all models above them have a pair of 10.25-inch units. The extra screen real estate is welcome, but we still find the larger screen's aspect ratio a little too wide, which limits the size of on-screen buttons and fonts.

We're less impressed with the system's graphics, however. Menus often look quite cluttered, without much consistency between different functions and it's not always obvious how to move forwards or backwards between submenus. There are physical controls for the climate settings, but the only indicator that they're actually doing anything when you adjust them is a small on-screen popup. There is a more in-depth climate control menu available through the screen but the route to accessing it isn't obvious. We're sure the system gets easier to navigate once you're used to it but it lacks the intuitiveness of the best infotainment setups we've used.

This is a strong suit for the GLB but it doesn't quite score a perfect 10. We found the car makes the most sense as a five-seater with the sixth and seventh seats folded flat, reserved for occasional use.

Set up this way, there's lots of space for front passengers, lots of space for rear passengers, and a big square boot that's perfect for a dog or a bulky pushchair. The second row of seats can individually recline and the whole row can slide on rails – that means you can adjust it for maximum legroom and comfort, with excellent access thanks to the large side doors.

Where the GLB falls apart, however, is when you try to use it as a seven seater. You're supposed to slide the second row forward to allow access to the sixth and seventh seats, but there simply isn't enough space for even especially flexible passengers to get in – you might need to fold a middle seat down to make access easier. Only with lots of negotiation between the front seats and second row can you eke out enough room to actually scramble into the third row.

Once back there, there's such a laughably small amount of head and legroom that only very short passengers will be able to fit. That means the GLB certainly isn't a good choice if you're going to need the sixth and seventh seats regularly, as using them means all passengers will have to squash up to fit everyone in.

As a slight silver lining, there's still get enough cargo space in seven-seat mode for a small weekly shop or perhaps a couple of cabin bags. However, considering how much more useful the boot is in five-seat mode, this is still the setting we'd find ourselves using most often.

Entry-level GLB 200 models use a 1.3-litre turbo petrol engine which, like all models in the lineup, comes paired with an automatic gearbox. With 163hp on tap, performance is reasonably strong and, in other cars we've tried this engine in, responsiveness to throttle inputs tends to be quite quick so it's easy to use around town.

Diesel buyers are well catered to with a pair of 2.0-litre options. GLB 200d models make 150hp or you can step up to the GLB 220d for 190hp and punchier acceleration. The latter also includes the brand's 4Matic all-wheel-drive system for better all-weather grip. Both of these models should be able to return more than 45mpg over a longer drive.

Our test car, however, was the range-topping GLB 35 AMG model. That means it gets a beefy 2.0-litre turbo engine with 306hp and grippy all-wheel drive, along with clever suspension and driveline tech for better cross-country performance.

Acceleration is mightily impressive, with big slugs of power available at nearly all engine speeds. Lean hard on the throttle and you'll quickly find the GLB travelling at speeds that feel unbecoming in a seven-seat SUV – your passengers certainly won't thank you for exploring the limits of the car's power. The suspension and electronics keeps everything in check of course, but it's easy to feel flung about in the AMG-powered GLB on anything other than totally smooth surfaces, mainly because you sit higher up than most performance cars, exaggerating the body's movements.

AMG models take a couple of hits to their refinement on the road. The monstrous engine is constantly grumbly, even when just pootling about. This fits with the car's manic character, but might get a little frustrating if you're just looking to get home after a long day. You also get huge wheels with fat, grippy tyres, which make a constant roar over most road surfaces. It's not unreasonable to expect these compromises in a car with so much performance, but lesser non-AMG GLBs are quite a bit smoother and quieter.

Mercedes has set the GLB up to be fairly forgiving. There's loads of grip and a generally reassuring, planted feel on the move. You'll also find a fair amount of body roll through corners, which reminds you not to drive this family car too hard.

The steering is linear and predictable, and you don't find yourself making wild stabs at the pedals to get the GLB to respond. It's sharp and reactive when setting off, and modulating the brake pedal is fuss free.

We drove the GLB 35 AMG on our test, which gets firmer adaptive suspension and fat, grippy tyres. Mercifully, however, this model isn't too harshly sprung either, with most of the compliance of the standard car remaining intact. You'll only start to feel the car's not-insignificant weight if you really start to deploy the AMG's power, which will probably rouse a chorus of complaints from passengers long before you get to the limit of performance.