MG Im6 vs Mercedes-Benz GLS-Class

What's the difference?

A super solid first outing from the IM brand. Don't let the pricing fool you, there is still bang for buck on offer in the IM6 Performance, even if it at times feels a bit too digital for my tastes.

The GLS63 is an intimidating beast from afar, but it rewards its occupants in almost every way. Yep, there really isn’t a box it doesn’t tick without serious compromise, such is its breadth of capability.

If there was ever a Swiss Army Knife of cars, the GLS63 is definitely a contender for the title, one that makes it very hard to wipe the smile off your face. Just make sure you can fit it in your garage first…

I feel almost mean saying this, because there will be plenty of people who like the way the IM6 looks, and I don’t want to rain on their parade. But… I’m not one of them.

It reminds me a bit of the pre-facelift Tesla Model Y, in that it’s largely feature-less and a bit blobby, and there’s not a sharp angle anywhere to be found on the thing. Premium to me means powerful and assured — picture just about any Audi — whereas I just find this a bit bland and soft.

Anyway, I do like the big alloys, the insulated glass roof and the light treatment front and rear.

And I like the cabin. The seats aren’t leather, but they’re super thick and comfortable, and there is a genuinely premium air in the cabin, helped by the acreage of screens and the quality elements, like the little door panels.

The doors unlatch electrically, matching the pop-out door handles outside, but they can be a bit fidgety. Someone from MG told me how they worked (you kind of cover the handle and let the door come to you) but I watched everyone else who tried to open them struggle. If you're at the point where you have to explain how a door handle works, you might have over-egged the pudding.

The second screen below the main one acts a bit like a mobile phone. You can alter your home screen widgets and access the main menu, even as Apple CarPlay is synched at the top. You’ll get used to it, I’m sure, but I found it to be a bit fidgety.

Actually it reminds me a little bit of the Lexus trackpad, or whatever that hateful system was called, where you controlled the main screen via a little mousepad thing, though happily it’s nowhere near as annoying as that was.

If the GLS63 was a Marvel superhero, it would undoubtedly be the Hulk. Simply put, it has road presence like few others. In fact, it’s frankly menacing.

Of course, the GLS is already pretty intimidating due to its sheer size and blocky design, but the GLS63’s full-fat AMG treatment takes it to another level.

Naturally, the GLS63 gets an aggressive body kit, with its purposeful bumpers, side skirts and rear spoiler serving as instant reminders of what you’re dealing with, but it’s AMG’s signature Panamericana grille insert that really hammers home the point.

Around the side, the GLS63’s 22-inch alloy wheels with staggered tyres (front: 275/50, rear: 315/45) make their presence known, positioned below the wheelarch extensions.

That said, some fun’s also had at the rear end, where the GLS63’s diffuser element integrates the foreboding sports exhaust system with quad tailpipes very neatly.

The focused Multibeam LED headlights also look the part, while the opposing LED tail-lights tie everything together outside quite nicely.

Inside, the GLS63 stands out from the GLS crowd with its sports steering wheel with Dinamica microfibre accents, and multi-contour front seats, which are covered in Nappa leather alongside the armrests, dashboard and door shoulders and inserts.

Of note, the doors bins are unfortunately of the hard plastic variety, which is very disappointing in a vehicle that costs this much. You would expect that cow hide would also been applied to them, but alas it isn’t.

The GLS63’s black headliner serves as an obligatory reminder of its sporting intent, and while it makes for a dark cabin, metallic accents are prominent throughout, while the optional trim (our test vehicle had carbon-fibre) mixes things up, alongside the ambient lighting.

And let’s not forget the GLS63 is still loaded with plenty of cutting-edge technology, including a pair of 12.3-inch displays, with one the central touchscreen and the other the digital instrument cluster.

Both are powered by Mercedes’ class-leading MBUX multimedia system and feature Apple CarPlay and Android Auto support. This set-up arguably remains the best there is today thanks to its speed and breadth of functionality and input methods.

The IM6 measures 4904mm long, 1988mm wide and 1669mm tall, and it rides on a 2950mm wheelbase, with IM describing it as a "mid-large SUV", though I expect it will be classed as a medium SUV Australia.

That said, ICE and EV mid-size electric SUVs are not cut from the same cloth, with the latter making use of a flat floor to maximise space. And so it is with the IM6, where backseat room is pretty damn impressive. I’m 175cm, and I had no problem at all with legroom or headroom, plus the same plush seats from up there are in the back, too.

There are also air vents but no temperature controls, and while there are USB ports, there is no regular household-style plug in the cabin. 

The glass in the windows is laminated, while the roof is double glazed, which MG tells me is Australian summer-proof, but I guess we'll know for sure in a couple of months.

There’s no shortage of cargo room either. There’s a 32-litre frunk up front, and there’s 646 litres in the boot with the rear seats in place. They’re 60/40 split, and if you drop them, luggage space grows to 1621 litres.

The towing capacity is a braked 1500kg, too, but I don’t expect to see many of these towing a camper trailer around.

Measuring 5243mm, 2030mm wide and 1782mm tall with a 3135mm wheelbase, the GLS63 is an upper-large SUV in every sense of the term, which means it’s also very practical.

For example, cargo capacity below the load cover is decent, at 355L, but stow the 50/50 power-split-folding third row via the boot and it’s very good, at 890L, or drop the 40/20/40 power-split-folding middle bench, too, and it becomes a cavernous 2400L.

Better yet, the boot’s aperture is almost square, and its floor’s flat, while there’s no load lip to contend with, making loading bulkier items even easier. Up to four tie-down points are also on hand (depending on seating configuration) to secure loose cargo.

Under the false floor is the space-saver spare, which is to be expected, but what isn’t expected necessarily is the fact there’s also enough room there for the cargo cover when it’s not in use, which would be the case if six or more passengers are regularly onboard.

Moving into the power-sliding second row, the GLS63’s practicality is once again brought to the fore, with up to six-plus inches of legroom available behind my 184cm driving position.

There’s also two inches of headroom with the panoramic sunroof in situ, not to mention just enough toe-room. The GLS63’s small transmission tunnel and sheer width also mean three adults can be seated on the middle bench with few complaints.

Amenities-wise, the second row has map pockets on the front-seat backrest and a small fold-down cubby below the rear climate controls, with it containing two slots for smartphones and a pair of strategically placed USB-C ports.

The rear door bins can take one large bottle each, while a fold-down central armrest is also on hand, featuring a shallow tray and retractable (and flimsy) cupholders.

Alternatively, the $2800 Rear Seat Comfort Package fitted to our test vehicle subs in a tablet that can control the multimedia system, a wireless smartphone charger and a small cubby into the former, as well as a heated/cooled cupholder atop the rear of the centre console.

In the third row, it’s not quite as roomy if you’re an adult. With the middle bench in its most accommodating position, my knees still brush up against its backrest, which is to be expected given it’s primarily designed for children. I also have an inch of headroom there.

Nonetheless, getting in and out of the third row is relatively easy as the power-operated middle bench tumbles forward and provides just enough space to make entry and exit somewhat graceful.

When seated, rear occupants are treated to two USB-C ports and one small cupholder each, so they’re arguably taken better care of than those in the middle.

Child seats are well and truly accommodated, with four ISOFIX and five top-tether anchorage points fitted across the second and third rows, although the latter will inevitably prove to be a much tighter fit.

The driver and front passenger are still taken care of, with a front cubby taken up by two heated/cooled cupholders, a wireless smartphone charger, two USB-C ports and a 12V power outlet, while their door bins take one large and one small bottle each.

In-cabin storage options include the large central storage bin, which hides another USB-C port, while the glovebox is on the smaller side, with about a third of it taken up by the fragrance, which is pumped into the cabin to ensure the interior always smells its best.

Priced from $255,700 plus on-road costs, the GLS63 commands a $34,329 premium over its predecessor, although buyers are arguably getting more bang for their buck than before, even if it does sit well clear of the two other GLS variants: the $147,100 GLS450 and $153,900 GLS400d.

Standard equipment not already mentioned in the GLS63 includes regular metallic paintwork (our test vehicle was finished in Selenite Grey), dusk-sensing lights, rain-sensing wipers, power-folding side mirrors with heating, soft-close doors, roof rails, rear privacy glass and a power-operated tailgate.

Inside, keyless entry and start, augmented reality (AR) satellite navigation with live traffic, digital radio, a 590W Burmester surround-sound system with 13 speakers, a head-up display, a panoramic sunroof, heated seats (including middle outboard) and armrests, cooled front seats with massaging functionality, power-adjustable seats, a power-adjustable steering column, temperature-controlled front cupholders, five-zone climate control, stainless-steel pedals and an auto-dimming rearview mirror feature.

With BMW not offering an X7 M (although the slightly smaller $209,900 X5 M Competition is available) and the $208,500 Audi RS Q8 really from the segment below, the GLS63 does not have a direct rival in the Upper-large SUV segment.

In fact, the $334,700 Bentley Bentayga V8 is actually the model that comes closest to the GLS63 when looking for a seven-seater with a similar level of bent-eight performance.

This is the real party trick of the IM6, because there’s a nuclear power plant under the metal somewhere. All up, the twin-motor setup produces a total 578kW and 802Nm, though I suspect you’re never accessing all the grunt all at once. Still, 100km/h zips by in 3.4 seconds, and the top speed is 239km/h. For the record, that’s exactly as fast the Ferrari Roma Spider I recently handed back, so yeah, it’s properly supercar quick.

The GLS63 is powered by a familiar 4.0-litre twin-turbo V8 petrol engine, with its version producing a thumping 450kW of power at 5750rpm and 850Nm of torque from 2250-5000rpm.

This unit is mated to a nine-speed torque-converter automatic transmission and AMG’s fully variable 4Matic+ all-wheel-drive system with torque vectoring and a rear limited-slip differential.

This set-up also features Mercedes’ EQ Boost 48V mild-hybrid system, which actually gives a 16kW/250Nm electric boost in short bursts, such as when accelerating off the line.

Speaking of which, the GLS63 sprints from a standstill to 100km/h in just 4.2 seconds, while its top speed is electronically limited to 250km/h.
 

Also on board is a 100kWh Nickel-Cobalt-Magnesium battery that produces a WLTP driving range of 505kms. Pretty good.

Charging is strong, too. The high-tech platform allows for 396kW DC fast charging, which is faster than what is currently offered in Australia. The claim is 30-80 per cent charged in 15 minutes. There’s also an external vehicle-to-load (V2L) port.

The GLS63’s fuel consumption on the combined-cycle test (ADR 81/02) is 13.0L per 100km, while its carbon dioxide emissions are 296 grams per km. All things considered, both claims are unsurprisingly high.

In our real-world testing, we averaged a fearsome 18.5L/100km over 65km of driving, split between highways and country roads, so not your usual mix. A very heavy right foot definitely influenced that result, but don’t expect to do too much better in a normal run.

For reference, the GLS63’s 90L fuel tank can be filled up with 98RON petrol at a minimum.

First things first, don't get too distracted by the word "performance" here. The IM6 doesn't act like a performance car, it feels bit too plush, and bit too digital, for that.

But that's not necessarily a bad thing. Performance cars are often loud, raucous and uncomfortable, and the IM6 is none of those things. Instead, those mountains of power and torque make silky, silent progress absolutely effortless, which feels pretty premium to me.

MG makes a big deal of how much work went into insulating the cabin from noise – with active noise cancellation joined by double-paned insulated glass – and it is a properly calming and quiet space.

Also strong is the suspension, with the adaptive air setup soaking up most bumps and bruises, but I found it can clang over really solid bumps, sounding like it's bouncing off a stopper. The steering is solid, too, with a nice weight, if not overly talkative in the feedback department, while the rear-wheel steering helps eat into the turning circle for tight three-point turns.

The downside, though, is that it all feels a little too digital, and like there's been a little too much overthinking gone into it. Having to push a button to see behind you in a hurry is bonkers (see my explanation in the Safety section below), and the secondary screen is more annoying than intuitive. And there were several bings or bongs I couldn't even identify. All of which interrupts the otherwise calming nature of the drive experience.

Frankly, the GLS63 has absolutely no right being as capable as it is. It’s a really big bus that’s legitimately convinced it’s a sports car half its size.

Being a GLS variant, the GLS63 has independent suspension consisting of four-link front and multi-link rear axles with air springs and adaptive dampers, but its party trick is the addition of active anti-roll bars.

In what feels like magic, the GLS63 is simply not intimidated by corners, despite having massive dimensions and a considerable 2555kg (kerb weight) to deal with.

The active anti-roll bars make the GLS63 so much easier to drive fast through the twisty stuff, almost eliminating body roll, taking one key variable out of the equation for the driver. Active engine mounts are also fitted, helping to settle things even further.

The electric power steering on hand is also good. It is speed-sensitive and has a variable ratio, which basically makes the set-up more direct when it needs to be. It’s typically light in hand, too, until one of the sportier drive modes is engaged and extra heft is added.

So, handling is scarcely believable, which means the ride must be compromised, right? Yes and no. With the adaptive dampers in their softest setting, the GLS63 is very compliant. In fact, we’d say it feels luxurious when compared to other high-performance SUVs.

That said, our test vehicle was fitted with the optional 23-inch alloy wheels ($3900), which look the part but expose sharp edges and other road imperfections, not to mention generate noise easily heard inside. Naturally, feedback is exacerbated in the sportier drive modes.

Anyway, there’s more performance, and the GLS63 has the rest in spades. Its engine is a powerhouse in every sense of the word. It’s so powerful, in fact, that it hilariously hunkers down off the line or when suddenly accelerating at low speed.

Thanks to the mild-hybrid system, wads of torque is available from the get-go, making for a highly responsive driving experience, even in those rare moments when the engine isn’t on song.

While not as characterful as some of the other members in the 63 series, the GLS63 still makes some thoroughly entertaining noises, with its sports exhaust system popping like mad while on the overrun.

All of this ability is very well and good, but you need to be able to pull up quickly, and the high-performance braking package (400mm front and 370mm rear discs with six-piston fixed callipers and single-pot floating stoppers respectively) mercifully does exactly that.

Neither ANCAP nor its European counterpart, Euro NCAP, have awarded the GLS range a safety rating, but it’s fair to assume it would perform well in testing.

Advanced driver-assist systems in the GLS63 extend to autonomous emergency braking with pedestrian and cyclist detection, lane-keep and steering assist (including emergency), adaptive cruise control, active blind-spot monitoring, rear cross-traffic alert, traffic sign recognition, driver attention alert, high-beam assist, tyre pressure monitoring, hill-descent control, hill-start assist, park assist, surround-view cameras and front and rear parking sensors.

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. Yep, it doesn’t leave much to be desired on the safety front.

The IM6 is covered by a five-year, unlimited-kilometre warranty, rather than MG’S 10-year term. Capped-price servicing is offered for the first five years, with your total bill just under $3000. The service intervals are 20,000kms or 12 months.

As with all Mercedes-AMG models, the GLS63 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 GLS63’s service intervals are relatively long, at every 12 months or 20,000km (whichever comes first). Better yet, it’s available with a five-year/100,000km capped-price servicing plan, but it costs $4450.