MG Im5 vs Mercedes-Benz GLB-Class

What's the difference?

The MG IM5 Performance is fast, comfortable, quiet and super refined. Putting some minor spec and active safety niggles to one side, it offers the features, tech and price to match it with its well-credentialled and already popular mid-size EV sedan competitors. Is there room for one more? We think there should be.

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.

Playing spot the straight line on the outside of the MG IM5 is like an automotive design version of Where’s Wally? There aren’t many, in the midst of an unrelentingly curvaceous exterior treatment.

At close to five metres long and two metres wide the IM5 is appreciably longer (+211mm), a little wider (+27mm) and a bit taller (+33mm) than a Tesla Model 3. Think BMW 5 Series in terms of overall size.

And the soft-form shape is functional; the swoopy liftback boasting an ultra-slick 0.24 drag coefficient.

That said, I’m not convinced by the ‘Periscopic’ cameras informing the driver assistance systems from the front guards. They scream tacked-on afterthought. But a touch-only initial opening function for the flush door handles is cool and makes life easier.

The curves continue inside with soft-padded surfaces around the dash and doors, but the straight edge obviously came out for the 10.5-inch central media screen and vast 26.3-inch upper display. There are next to no buttons; even exterior mirror adjustment is directed from the screen to a multi-function steering wheel control.

System software (powered by a Qualcomm ‘Snapdragon’ chip) is lightning fast with a two-finger up and down swipe shortcut function on the central screen for ventilation and other functions.

The interior is light and bright thanks to the enormous panoramic sunroof. It’s been fine in cooler winter conditions during this test but it could be interesting to revisit in the heat of an Aussie summer

There are two interior colour schemes available - the ‘Highland Grey’ of our test car or ‘Dover Beige’ for those brave enough to live life with the threat of scuff marks on your shiny new car’s glamorous but vulnerably light interior.

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 plenty of breathing room up front and in terms of storage one of the first things worth calling out are the long but relatively narrow door bins. No good for anything above unusually slender bottles, even if they’re lying down.

No conventional glove box in the dash, but there is a large lidded box (cooled and heated) between the seats that doubles as a centre armrest. It’s supplemented by a big stowage area underneath the flying buttress style centre console.  

There are two cupholders in the centre console as well as a wireless device charging pad in front of them with a vaguely phone-shaped oddments bin alongside it.  

Move to the rear and the IM5’s 75mm wheelbase advantage over the Tesla Model 3 is clear. Heaps of knee and headroom for me at 183cm sitting behind the driver’s seat set to my position. 

But… the seat sits low which pushes your knees up into the air to the point where my thighs are not contacting the seat cushion. Even though the rear seat reclines to a certain degree it’s a problem compounded by a chronic lack of room for your toes under the front seat. Awkward.

There are map pockets in the front seatbacks, modest bins in the doors and a fold-down centre armrest with two cupholders. Adjustable ventilation in the rear of the front centre console always makes life in the rear seat more pleasant.

The car also houses ‘Strong Magnets’ at various points around the cabin and boot, with a configurable adapter able to lock a phone or tablet into place for the entertainment of, in our case, back seaters. 

Speaking of devices for entertainment, there are two USB-C sockets and a 12-volt outlet in the front and another USB-C and 12V in the back, so charging isn’t an issue. 

The IM5 is a liftback so the boot aperture is generous and a capacity of 457 litres with the rear seats up is decent for a car of this size, although that’s less than the Tesla Model 3 (594L) which has an additional well under the floor. 

Still, enough room for the largest (124L) and smallest (36L) suitcases from the CarsGuide three-piece luggage set with some room to spare.

The power tailgate can be operated hands-free via the key or an always welcome under bumper kick function.

Volume expands to 1290 litres with the rear seats folded and there’s a modest 18-litre ‘frunk’ under the bonnet.

The bad news is a repair-inflator kit rather than a physical spare wheel, but the better news is the IM5 Performance can tow a 1500kg braked trailer (750kg unbraked).

The IM range also features the ‘MG iSmart’ app allowing remote control of various functions including charging, checking vehicle location and route planning. 

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).

The MG IM5 Performance is powered by an electric motor on each axle - the rear (372kW/500Nm) more powerful than the front (200kW/300Nm), for overall outputs of 572kW (that’s close to 770hp) and 802Nm of pulling power.

The official term for that amount of grunt is… a lot. And we’ll get to what it means on the road in the Driving section shortly.

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 MG IM5 Performance features an 800-volt electrical architecture which means the 100kWh NCM battery can accept a DC peak charge of close to 400kW.

Only snag is the highest you’ll currently find in Australia is 350kW. But even at that rate you’ll still be looking at a 30-80 per cent charge in just over 15 minutes. Maximum AC charge rate is 11kW.

Claimed range is 575km (WLTP) which is less than the Tesla Model 3 Dual Motor AWD at 629km.

Over a week of city, suburban and some freeway running we saw average energy use of 20.6kWh/100km which is on the high side for an EV of this size but maybe not for one with this kind of performance potential. 

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 things first, the IM5 Performance is supercar fast. This 2.3-tonne five-seater blazes from 0-100km/h 3.2 seconds and with its dual motors combining to produce 572kW/802Nm, eye-widening performance always resides underneath your right foot.

But it’s not all about straight line speed. Ride comfort is excellent. Underpinned by an all-new platform, the IM5’s suspension is by double wishbones at the front and multi-links at the rear. But the key to its bump and rut smoothing ability is air suspension and ‘continuous control’ active damping.

Fold in double-glazing on the full-length glass roof and side windows, as well as active noise cancellation and you have a serene interior environment at any speed. Also worth noting the front seats are great; as grippy as they are comfortable.

Not only that, despite its relative heft, this mid-sizer steers well, too. Not the last word in road feel but it points accurately and the standard rear steering helps with prompt (but never jerky) cornering turn-in. Flick to ‘Sport’ mode and the IM5 is up for some enthusiastic running.

The rear wheels can turn up to 12 degrees in the opposite direction to the fronts at slow speed, which makes for a usefully tight 10-metre turning circle. But above that, at lesser angles, it adds extra stability and decisiveness in the way the car steers through even tight, twisty sections.

Rubber is top-shelf Pirelli P Zeros on 20-inch alloys (245/40 fr - 275/35 rr) and it grips hard, especially in the wet weather over much of the test period. Braking is solid, as it needs to be, with ventilated discs all around and four-piston callipers at the front. 

No adjustable regen braking but you can feel the ‘Cooperative Regenerative Brake System’ (CRBS) doing its thing when you lift off the accelerator. 

The physical rear view is modest thanks to the slope of the back window reducing its functional area for the driver to that of a 1950s VW Beetle. Even the interior rear-view mirror is tiny and folds up into a recess in the headliner if you’d prefer life without it.

But that’s where a rear camera view popping up on the upper screen display (accessed via the right-hand steering wheel click control) comes in handy. Side camera views are also available as is a 360-degree overhead view, which makes parking straightforward.

If you need more parking help there are various self-parking modes including a nifty ‘Curbside’ function that will realign the car hands-free if you’re parallel parked too far out from the kerb.

In a similar vein, a ‘Rainy Night’ mode projects left and right rear views onto the main screen using AI to enhance clarity and highlight pedestrians and cars.

Overall the ADAS (Advanced Driver Assistance Systems) are relatively unobtrusive but we found ourselves switching off the incessant overspeed chime that sounds for 10 seconds if you creep over the indicated speed limit, even when the system has misfired on the correct speed. For example, 40km/h school zones on a Sunday.

The over-zealous driver distraction warning also occasionally issued a visual and audible slap on the wrist when I was looking straight ahead. Tellingly, there’s a specific quick screen for turning both these functions off, but it kinda defeats the purpose of having them in the first place.

We also found the adaptive cruise control to be hesitant in multi-lane environments, reducing speed occasionally because the system seemingly believed a car was set to merge, when it wasn’t.

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.

The MG IM5 Performance is covered by a seven-year/unlimited km warranty, which is a plus, but the catch is it’s conditional on authorised dealer servicing. Go elsewhere and the term drops to a more common five years/unlimited km. The drive battery is covered for eight years/160,000km, which is the norm in the Aussie market

Servicing is required every 12 months or 20,000km with charges averaging $586 per workshop visit for the first five years, which is on the high side for an EV, even at this price point, the average bumped up by a more than $1400 doozy at year four.

MG IM models are sold (with service available) through all of MG’s 100-plus dealerships across the country, so no concerns there.

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.