Mercedes-Benz GLB-Class vs Mercedes-Benz CLA45

What's the difference?

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 new CLA 45 S has knockout performance to match its knockout looks, neither of which are much of a surprise given the ingredients involved.

That said, it is far from perfect, with questions raised over its value and practicality. And for those reasons, we’d be buying the A 45 S hatch instead.

Is the new CLA 45 S worth such a hefty premium over its non-S predecessor? Tell us what you think in the comments below.

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.

There’s simply no mistaking the CLA 45 S from its CLA siblings. It’s angry and stylish, at the same time.

Up front, Mercedes-AMG’s signature 'Panamericana' grille insert is large and in charge, flanked by adaptive 'Multibeam' LED headlights that incorporate sinister-looking daytime running lights (DRLs).

The real action, however, is happening below, where the AMG body kit starts to come into frame. It’s delightfully chunky and highlighted by cavernous side air intakes, which hint at the sledgehammer residing beneath a bonnet featuring prominent power domes.

Around the side, the CLA 45 S does its best impersonation of a coupe, with a sloping roof line and a curvaceous glasshouse. It also brings the aggro with a particularly sporty set of 19-inch alloy wheels, which flank pointy side skirts.

At the rear, the CLA 45 S again hints at its performance level, this time with a bootlid lip spoiler, although look past its LED tail-lights and you’ll find the star of the show, a furious diffuser that houses the quad 90mm tailpipes of the AMG sports exhaust system.

Inside, the CLA 45 S is pretty special. While the CLA certainly provides the building blocks, it goes a step further with a number of unique touches.

Your eyes are immediately drawn to the wickedly cool 'Dinamica'-trimmed AMG Performance steering wheel, which not only has paddle-shifters, but also features two ‘display buttons’ that make adjusting vehicle settings on the fly super easy.

Then there are the front sports seats, which are covered in Lugano leather upholstery alongside the armrest door inserts, while artificial cow hide trims the upper dashboard and door shoulders.

Hard plastics? You’ll need to look lower than the soft-touch middle dashboard to find them, as they are primarily confined to the lower sections of the cabin. And yes, some of the switchgear is very cheap for a six-figure performance car.

One personal bugbear, though, is the liberal use of gloss-black trim for the centre stack and console. Not only is it a fingerprint magnet, but it scratches easily, too. The brushed stainless-steel and silver accents elsewhere are nice, though.

While stainless-steel sports pedals also help to make the CLA 45 S stand out from the CLA crowd, it is otherwise a carbon-copy of its siblings, which is no bad thing.

Of course, the headline act is the pair of 10.25-inch displays, with one a touchscreen that is partially concealed by the steering wheel, while the other is a digital instrument cluster.

The former delivers the now-familiar 'MBUX' multimedia system, which is still at the cutting edge when it comes to functionality, especially with its always-on natural voice recognition, which is as good as it gets, albeit not perfect.

There are, of course, more input methods, with two small touchpads located on the steering wheel, while a larger item sits on top of the centre console, supported by a palm rest. There are also shortcut buttons and physical climate controls.

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.
 

Measuring 4693mm long, 1857mm wide and 1413mm tall, the CLA45 S is actually similar in size to a C-Class but not quite as practical.

Cargo capacity is pretty good, at 460L, but can be increased via the 40/20/40 split-fold three-seat rear bench stowed – an action that can be performed via the boot’s manual release latches, although it doesn’t tumble forward by its lonesome.

Speaking of the boot, four tie-down points are on hand for to help loose loads alongside two side storage nets. Bulkier items will have to contend with a tall load lip. That said, the boot’s aperture is much wider than before, which is good news.

In-cabin storage options are okay, with the glove box decently sized and the map pockets of the net variety, while the central bin is fairly average, although it does house two USB-C ports.

There’s also a standard sunglasses holder and a cubby in front of the centre console’s two cupholders. It isn’t that useful, though, as the wireless smartphone charger takes up most of space alongside a USB-C port and a 12V power outlet.

The front door bins can accommodate two regular bottles each, while their counterparts in the rear take only one apiece. That said, the second row does have a fold-down armrest with another pair of (flimsy) cupholders.

Rear occupants don’t have a whole lot of room to play with, though. Legroom behind my 184cm driving position is pretty decent, at around four centmetres, but headroom is not. In fact, it’s non-existent sitting upright, with the panoramic sunroof not helping matters.

Toe-room is also at a premium alongside precious footwell space, which is reduced by the tall transmission tunnel. As such, the second row is best for up to two adults or three children at a time.

And if there are three occupants abreast, they’ll have to compete for the two USB-C ports, which are located in a fold-out cubby below the central air vents at the rear of the centre console.

For reference, child seats can be fitted in the second row thanks to top-tether and ISOFIX anchorage points, although both are only available for the outboard seats.

Priced from $111,200 plus on-road costs, the CLA 45 S is a staggering $20,530 dearer than its non-S predecessor. Yep, it’s a hard number to digest at first, but Mercedes-AMG says the premium is justified due to a significant step-up in specification.

Standard equipment not already mentioned includes dusk-sensing lights, rain-sensing wipers, a tyre repair kit, power-folding side mirrors with heating, rear privacy glass, satellite navigation, Apple CarPlay and Android Auto support, digital radio, a 590W Burmester sound system with 12 speakers, keyless entry and start, dual-zone climate control, power-adjustable front seats with heating, an auto-dimming rearview mirror and LED ambient lighting.

Key options include the $2490 'AMG Aerodynamics Package' (high-gloss black front splitter, aero flics and larger bootlid lip spoiler), $3290 'AMG High Performance Seat Package', $790 cooled front seats and $790 'Communications Package' (windshield-projected head-up display). Only the latter was fitted to our test vehicle alongside no-cost 'Polar White' paint.

The CLA 45 S only has one direct rival, the $86,500 Audi RS3 sedan, although the $106,900 BMW M2 Competition coupe is more or less in the same league. Either way, the CLA 45 S is in another league when it comes to price and performance.

But you could also opt for its A 45 S hatch sibling for ‘just’ $93,600…

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 CLA45 S is motivated by the most potent series-production four-cylinder engine yet.

The 2.0-litre turbo-petrol unit punches out an astounding 310kW of power at 6750rpm and a significant 500Nm of torque from 5000-5250rpm – a marked 30kW/25Nm improvement over its non-S predecessor.

It’s also worth noting Mercedes-AMG performed “torque shaping” to make the new engine’s output delivery (or curve) akin to that of a naturally aspirated unit. This attitude also led to a screaming redline of 7200rpm.

An eight-speed dual-clutch automatic transmission is responsible for swapping gears, while Mercedes-AMG’s fully variable '4Matic+' system sends drive to all four wheels, although it does have a 'Drift Mode' that effectively disengages the front axle.

With the help of standard launch control the CLA 45 S sprints from a standstill to 100km/h in four seconds flat, while its top speed is electronically limited to 270km/h.

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.

Fuel consumption on the combined-cycle test (ADR 81/02) is 8.9 litres per 100 kilometres for the CLA 45 S, while its claimed carbon dioxide emissions are 202 grams per kilometre. Both are pretty keen given the level of performance on offer.

In our real-world testing, we averaged 12.0L/100km over 270km of driving evenly split between city traffic and highways. This result was somewhat inflated by some ‘spirited’ driving but is certainly something we can learn to accept.

For reference, the 51L fuel tank in the CLA 45 S takes 98 RON premium unleaded petrol at minimum.

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.

When it comes to sheer driving pleasure, the CLA 45 S is a huge step-up over its non-S predecessor.

Of course, the 2.0-litre turbo-petrol four-cylinder engine will steal all the headlines, and rightfully so; it’s the most potent unit in its class by some margin.

In reality, it absolutely slaps. Simply put, acceleration is addictive, and not just because of the outputs, but also the way in which they’re delivered.

The CLA 45 S does its best impression of natural aspiration, and I can’t help but award it an automotive Oscar.

Don’t get me wrong, performance is still strong down low (despite a hint of turbo lag), with it progressively building into, and through, a hard-hitting mid-range before reaching a knockout top end that you’ll want to revisit time and time again.

That said, it does take two to tango, and what a dancing partner the eight-speed dual-clutch automatic transmission is.

It’s almost flawless, with its gear changes stereotypically super quick but uncharacteristically buttery smooth at the same time.

Responsiveness is another strong point, although it does sometimes have difficulty recognising when the fun is over, as it can hold onto the short lower gears for a little longer than necessary.

And despite our initial fears, the CLA 45 S is still very, very vocal, with its sports exhaust system serving up plenty of aural pleasure, albeit not quite as much as the original CLA 45.

The soundtrack is booming and is complemented by plenty of pops on downshifts and the overrun as well as frightening crackles when aggressively up-shifting . But these theatrics require the Sport Plus drive mode to be engaged, which opens up an all-important exhaust valve.

Given the level of performance on offer, you’d be right to assume the CLA 45 S has a firm ride, but it’s actually better balanced than most.

The 'AMG Ride Control' sports suspension on hand consists of MacPherson-strut front and multi-link rear axles with three-stage adaptive dampers, which progressively stiffen things up.

However, all is relatively comfortable, even in the stiffest setting. In fact, only sharper edges are felt. It’s more than liveable, especially considering the benefits of the trade-off.

Speaking of which, the CLA 45 S loves to eat up corners. Handling is more or less neutral when pushing hard, at which point its 1687kg kerb weight starts to be felt.

Nonetheless, body control is very strong, partially thanks to the reinforced chassis, with only a hint of roll encountered when cornering with intent.

A lot of the credit has to go the fully variable 4Matic+ all-wheel drive system with rear torque vectoring, which provides outstanding grip, even in the poorest of conditions.

In fact, it bestows such confidence you'll want to push harder to try and find the limits of adhesion. A staggering effort.

The CLA 45 S isn’t without its flaws, though, with the electric power steering on tap good but not great.

It’s speed-sensitive and has a variable ratio, which mean it’s pleasingly light in hand at low speed and noticeably heavier at high velocity, with the latter exacerbated when playing with the available drive modes.

Either way, it’s nice and direct and provides a good amount of feedback through the wheel, but we feel Mercedes-AMG could’ve taken it even further in these two departments to really mix it up with genuine sports cars.

What isn’t half-baked, though, is the 'AMG High Performance braking system', which consists of 360 x 36mm front and 330 x 22mm ventilated discs with six-piston fixed and single-piston floating red callipers respectively.

This set-up washes away speed with ease, instilling the driver with even more confidence when tackling a winding road, while pedal feel is good. Yep, the CLA 45 S decelerates nearly as well as it accelerates.

ANCAP awarded the CLA range (excluding CLA35 and CLA45 S) a maximum five-star rating in 2019.

Advanced driver-assist systems (impressively) extend to autonomous emergency braking, lane-keep assist, active blind-spot monitoring, cross-traffic alert, adaptive cruise control, traffic sign recognition, high-beam assist, driver-attention alert, hill-start assist, tyre pressure monitoring, park assist, surround-view cameras and front and rear parking sensors. Yep, you’re not left wanting here.

Other standard safety equipment includes nine airbags (dual front, front and rear side, and curtain plus driver’s knee), the usual electronic traction and stability control systems, anti-skid brakes (ABS) and brake assist (BA), among others.

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.

Like all Mercedes models, the CLA 45 S comes with a five-year/unlimited-kilometre warranty, which sets the standard in the premium market. Better yet, five years of roadside assistance is also bundled in.

CLA 45 S service intervals are every 12 months or 20,000km, whichever comes first. A three-year/60,000km capped-price servicing plan is available for $3750, which is not cheap. That said, its pricing can be reduced by $750 if paid upfront alongside the vehicle.