Marbella, Spain - Mercedes’ first ever entry in the compact SUV class, the GLB was unveiled as a concept car at Auto Shanghai in April, with the production version presented at the GLS launch in Utah two months later.
Sharing its basic platform with the A, B, CLA and GLA-Class models, the GLB sits between the GLA and GLC, but lays claim to greater versatility and passenger carrying capacity than its bigger brother.
Sitting on a wheelbase stretched by 100mm over the A-Class the GLB’s clever packaging makes it the first and only compact SUV to offer the option of seven-seats. Sufficient leg and headroom in the third row for 1.68m tall passengers means this is not a token gesture only suitable for small children.
With the third seat row stowed away the GLB offers a spacious 570 litres boot, which swells to an impressive 1,805 litres (E-Class Estate 1,820 litres) with all the rear seats folded flat. Extra versatility comes from the middle row sliding back and forth on rails, and even when all the way forwards a 1.8 m tall passenger still has adequate legroom. With the seat positioned all the way back leg and headroom is more than generous.
Made at Mercedes’ plant in Mexico the GLB’s build quality and finish are second to none. The doors close with a satisfyingly solid old school Mercedes ‘thunk’ and its overall quality sets the bar very high indeed.
The entry-level GLB 200 we drove first is the only model available with front-wheel-drive, and as a vehicle for taking your kids, and their friends to school it works just fine
When you think of a turbocharged 1,332cc motor pulling a near 1,600kg family wagon eyebrows are raised rather high. But the smallest motor in the petrol engine range proved far more civilised and refined than we anticipated.
With two on board the power and torque from the small turbocharged motor proved adequate even on hills, but with a full load of passengers the jury is out on any notion of real performance.
That said the engineers have done a fine job on the refinement of the M282 family four-cylinder, which features cylinder shut-off for improved economy and emissions. Willing and responsive considering the size and weight of the GLB the motor dispenses its 163hp at 5,500rpm and 250Nm between 1,600 and 4,000rpm in a quite sophisticated manner. Part of this perceived refinement no doubt comes from the very effective engine bay encapsulation that as we later discovered stands the diesel variants in very good stead.
Once you reach cruising speed, whether that is 100km/h on a country road or 130km/h on the highway mechanical noise fades into the background, aided by the tall upper ratios of the 7G-DCT dual-clutch transmission. The cylinder shut-off and reactivation is imperceptible.
Apart from being front-wheel-drive the entry-level GLB 200 is the only variant that makes do with just seven forward gears, and at 1,555kg it is 115kg lighter than the GLB 250 4Matic.
While it is no ball of fire in speed gathering terms the GLB 200 is a fine partner in which to cover long distances in comfort and style. It has a supple and well-judged ride in Comfort mode, while Sport adds improved body control to the mix without eating too much into ride comfort. Many may settle on Sport as their open road default mode.
Thanks to the effective active damping and relatively long wheelbase the GLB 200 exhibits very good chassis composure when pushed hard on a twisty road. Only when accelerating hard in the lower gears in slippery conditions does it betray its lack of 4Matic credentials with wheelspin and axle tramp if you give it full beans in first gear before the ESP cuts in.
However, Mercedes has correctly judged that this model is most likely to do duty taking kids to school in an urban or suburban environment where this will likely never be an issue.
GLB 250 4Matic
With 224hp at 5,500rpm and 350Nm of torque from 1,800-4,000rpm the GLB 250 4Matic convincingly addresses the power and torque deficit of its smaller engined brother.
Taking 6.9 seconds for the 0-100km/h sprint and topping out at 236km/h the GLB 250 comes across as the consummate all rounder in the petrol engine range with its fine balance of comfort and performance. This comes as no real surprise since the same is true for the A 250 and CLA 250 models.
GLB 200d 4Matic
The entry-level 116hp GLB 180d was not at the launch. Like the petrol 200 it is front-wheel-drive only, but is paired with the 8G-DCT dual-clutch transmission fitted to all the other petrol and diesel models.
Our diesel experience was confined to the GLB 200d on the off-road course where it really shone. The OM654 family 1,950cc common rail turbo-diesel motor makes 150hp from 3,400 to 4,400rpm and 320Nm of torque from 1,400-3,200rpm. Top speed is 204km/h and the 0-100km/h time is a decent enough 9.0 seconds, but as always with diesels the good spread of torque on the fly and impressive fuel economy are where its real strengths lie.
First impressions as we set off were of impressive engine refinement and lack of diesel clatter. In fact from any of the passenger seats you can hardly tell there is a compression-ignition motor working away up front.
While the hang-on 4Matic is more of a traction-oriented system with some clever electronic helpers rather than a serious challenger to its mighty G-Class big brother, it works pretty well in moderately difficult off-road conditions.
Although the latest 4Matic is a hang-on system a major contributor to its seamless performance is the electro-mechanical actuation that replaces the electro-hydraulic system used before.
The old system required a relative speed differential between the front and rear axles for the clutches to lock up. This caused a small time lag and meant that there would always be a moment of wheelspin from rest on a slippery surface before the second axle came into play.
The new electro-mechanical system is able to couple the rear differential from zero speed delivering optimum grip from a standing start irrespective of the coefficient of friction under the four tyre contact patches. It also starts with a 50/50 torque distribution from where power is shifted to either axle according to available grip. Under light throttle load on the flat the system decouples the rear axle to save fuel and lower emissions.
While one of the major keys to mud-plugging ability is the right footwear Mercedes equipped their off-road test cars with winter tyres. “We want to give a realistic impression of the GLB’s off-road capability without resorting to specialised equipment,” said Gerald Feichtinger, the engineer who accompanied us on the off-road course.
It had rained almost incessantly since the day before and the mud quickly clogged the treads of the winter tyres rendering them like slicks as we made our way around the off-road course. Nonetheless the 4Matic system was able to claw the GLB itself round quite convincingly, the latest generation of fast acting traction aids working their magic quite unobtrusively in the background.
GLB 35 4Matic
AMG’s engineers have done a comprehensive job of giving the GLB 35 4Matic a sporting flair, but as the GLB is Mercedes’ entry-level SUV with a seven-seat option that makes it a family carrier there is a limit to just how much ‘sport’ can be stirred into the mix.
Shared with the A 35 and CLA 35 AMG but with unique calibrations for the heavier GLB, the 1,991cc motor M260 motor with its twin-scroll turbocharger and indirect water/air intercooling is a feisty unit that delivers 306hp at 5,800-6,100rpm, underpinned by 400Nm of torque between 3,000-4,000rpm.
Thus, despite a kerb weight north of 1,700kg the GLB 35 4Matic has more than enough performance to satisfy most people and really comes alive in Sport mode.
Project engineer, Bastian Bornemann explained that while boost is set at 1.6 bar with no overboost facility as such, the ECU mapping provides 50Nm more torque in first and second gears in Race Start mode to maximise acceleration off the line.
To cope with the extra power and torque the AMG Speedshift DCT 8G dual clutch gearbox contains five clutches instead of the normal four. With the 4Matic system conferring perfect traction off the line the stopwatch records a hot hatch snuffing 5.2 seconds for the 0-100km/h sprint. Top speed is electronically limited to 250km/h.
The sporting feel of the crisp throttle response and satisfying push in the back on full throttle is aided and abetted by a sonorous aural signature from the bespoke sound valve exhaust. Engage Sport mode and its vocal chords drop a further half octave. More musical to our ears than the rortier exhaust note of the A45 AMG, the more sophisticated overtones here are in line with the GLB’s more egalitarian ‘family and friends’ role in life.
A stiff body-in-white is the cornerstone of a good ride and handling compromise, and as always this is where the AMG chassis engineers begin their work. Being 100mm longer than the A-Class and with five openings in its body-in-white means the GLB needs a bit of help in the structural stiffness department.
The recipe AMG uses for increasing torsional rigidity here is almost exactly the same as on the A45 AMG we drove back in the summer. This starts with a three-piece alloy front suspension strut tower brace clearly visible when you open the bonnet.
Under the engine bay, where the cooking models use a plastic undertray as the front section of this aerodynamically flat bottom design, AMG bolt in an alloy panel to provide torsional reinforcement.
The third and final piece of the puzzle is two short diagonal braces that stiffen the connection from the front sub-frame to the bodyshell. These bracing components turn the front of the car into a very stiff ‘box’ that benefits ride and handling. Unlike the A45 and CLA45 AMG models however, there is no reinforcing member at the rear.
The revised suspension set-up features AMG specific springs and dampers that reduce the ride height by 20mm. It is noteworthy that even if you specify the optional sport suspension on a normal GLB the ride height is unchanged from standard.
The front lower suspension arms are given spherical bushes for improved steering response while the rear bushes remain rubber for bump compliance. The hollow steel anti-roll bars are uprated in both diameter and wall thickness, going to 26.0 x 4.0mm in diameter x wall thickness (GLB 250, 24.0 x 4.2mm) in front and 24.6 x 3.9mm (GLB 250, 21.4 x 4.3 mm) at the rear. The ratio of the revised front to rear bars is interesting as the larger rear bar clearly shows intent to reduce inherent understeer in the AMG version.
The alloy rear lower suspension arms are replaced with steel equivalents for added strength, while the rear sub-frame that is normally isolated from the bodyshell with four rubber bushes is now solid mounted to remove any lost motion when lateral loads are applied. As on the front axle the strengthened alloy wheel carriers are fitted with uprated bearings.
The base alloy wheels for the GLB 35 are 19-inch with the option of 20 and 21-inch. There are seven styles to choose from, which include colour variants. Our test car wore the largest of these with 235/35ZR21 Continental SportContact 6 rubber.
Behind these big wheels are 380mm diameter vented discs clamped by four pot callipers in front, and 330mm vented discs with single pot callipers at the rear. They stop the GLB 35 very effectively and have good pedal feel at all speeds.
The difference the AMG fettled chassis made is very obvious. Steering response is more direct, the front end turning in more keenly and roll in corners reduced. The GLB 35 simply feels more alive and raring to go, and even with the 306 horses in stampede mode the uprated chassis feels capable of handling even more power with room to spare.
The downside is that while the 21-inch wheels look great they make the ride a bit firm for our taste, in stark contrast to the supple and well-resolved ride we experienced with the normal GLB variants. We would like to try a GLB 35 wearing the smallest 19-inch wheels in order to deliver the final verdict.
Right now there are simply too many cars on sale for buyers to choose from, and Mercedes is as guilty as any car manufacturer of trying to find more niches to fill, sometimes just because they can.
Recent events have proven that even wearing the three-pointed star is not enough to guarantee sales success. Customers have voted with their wallets and Daimler boss Ola Kaellenius has told us that slow selling models will be axed. The once desirable SLC roadster has already ceased production, and the S-Class Cabriolet is not long for this world.
Apart from wealthy buyers who can afford several cars to perform varied tasks, today’s discerning buyers of prestige marques also seek, and indeed expect useful and practical features in their daily transport.
This is why for many, the seven-seats, roomy and well detailed MBUX-equipped cabin, impressive engine and chassis sophistication, and solid build quality all combine to make the new Mercedes GLB a uniquely compelling offer.