Mercedes-Benz GLS-Class vs Gac M8

What's the difference?

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…

The GAC M8 PHEV Luxury is a people mover that carves out a very specific niche, largely thanks to its plug-in hybrid powertrain and ambitious price point. It’s undeniably well specified and genuinely luxurious inside, but it never quite escapes its chauffeur-like identity as it's a vehicle built around passenger comfort rather than driver engagement.

Being a new brand in our market limits ownership appeal, at least for now. Where the M8 really impresses, though, is efficiency, and that alone may be enough to justify its unusual positioning.

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 GAC M8’s design is… well, it’s out there. This isn’t a people mover that fades politely into the background. There are clear parallels with the Lexus LM, right down to the towering grille (complete with a vague hint of spindle shaping), which may well be the tallest grille I’ve encountered!

It’s a big unit, too, measuring 5212mm long, 1893mm wide and 1823mm high. The overall shape is sharply squared-off and prioritises presence over dynamism. It also comes standard with a full suite of LED exterior lighting.

The cabin claws back some design cred, though, as it’s downright plush with its semi-aniline two-tone leather upholstery - finished in a lush burgundy/black duo in our test vehicle. Accent panels vary between a diamond-design for the dashboard and doors, to suede soft-touchpoints and rose-gold inserts liberally scattered across the cabin. 

The only accent that doesn’t land is the large swathes of piano black on the centre console as it’s hard to keep clean.

There are some nice little surprises, too, like the fidget spinner-style crystal gear lever, which is surprisingly fun to fiddle with at traffic stops and two sunroofs with the rear fixed panel illuminating with internal ambient light.

Some of the finishes aren’t the best as there are joinery and door handles that don’t line up properly, which is surprisingly more annoying than you’d think once you notice it. But overall, the cabin feels well-considered and luxurious, even if the execution isn't always flawless. 

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.

The front row has plenty of space and the seats feature heating and ventilation, making longer journeys comfortable. However, there’s no extendable under-knee support and only the driver gets lumbar adjustment. I’ve spent much of the week feeling like a chauffeur, as my husband and child insisted on sitting in the back!

The middle row is where the M8 really shines. The captain’s chairs are indulgent, offering full recline, footrests, heating, ventilation, and massage. Comfort is excellent, though the footrest extension limits space for the third row, and even at 168cm I found it a snug fit when fully reclined. Access is straightforward with grab handles and a low 143mm step-in height, though be mindful of kerbs as the doors aren’t forgiving when it comes to tall council strips.

The third row is one of the few that genuinely accommodates adults. Head- and legroom are ample, and the seats feel firm but comfortable, especially with the foldable armrest. Amenities aren't forgotten with four cupholders, two USB-A ports and directional air vents. Access requires sliding through the middle row, so it’s best if those seats are unoccupied, but otherwise it’s not too taxing.

Front-row storage is practical, with a mid-sized glove box, dual-opening middle console, cupholders and a clever phone cradle that integrates a wireless charging pad and cable routing for a tidy set-up. There’s also a USB-A and USB-C port and a 12-volt socket in the large shelf underneath the centre console.

The middle row enjoys three USB-A ports, a USB-C port, directional air vents, retractable sunblinds, tray tables (though not usable while driving) and climate control. Storage is decent, with six cupholders, one of which has heating and cooling, two map pockets, a pull-out drawer and a 220-volt AC outlet.

The 10.1-inch touchscreen multimedia system is serviceable but feels slightly small for the luxury segment. Graphics aren’t the sharpest, the layout isn’t always intuitive and some functions, like the heated steering wheel, require digging through menus. Wireless Apple CarPlay and Android Auto performed flawlessly throughout the week and the 12.3-inch digital instrument cluster is clear and well laid out.

Boot space is modest for a people mover, offering 280L with all rows in place which is enough for a small grocery run but not for a fully-loaded family outing. Folding the third row expands capacity to 1500L, though that leaves you with a four-seater. The loading height is low, which helps, but it has a tall lip which prevents it from being ideal for sitting on during tailgates or picnics. There’s a small underfloor compartment housing the tyre repair kit and a powered tailgate rounds out the package.

There are two grades available for the GAC M8, and for this review we’re in the flagship Luxury, priced from $83,590, before on-road costs. It’s an awkward vehicle to compare because, right now, it’s the only people mover on sale with a plug-in hybrid powertrain.

Its closest like-for-like rivals in terms of size, specification and middle-row captain’s chairs are the all-electric LDV Mifa 9 Luxe and Zeekr 009 (FWD), priced from $129,000 and $115,900, before on-road costs, respectively. Compared to them, the M8 presents strong value. The equation looks less convincing when it’s parked alongside the flagship Kia Carnival Hybrid, which starts from $76,630 MSRP, though the intended markets between the two are notably different.

GAC hasn’t held back on features in the Luxury grade. The front and middle-row captain’s chairs are power-adjustable and offer heating and ventilation, with the middle seats also gaining full recline, extendable footrests and a massage function. Curiously, the driver misses out on massage, though.

Other highlights include a front sunroof with manual blind, a second fixed glass roof, semi-aniline leather upholstery for the first two rows with leather in the third, and a heated steering wheel. Practical conveniences are well covered too, with powered sliding rear doors, a hands-free powered tailgate, acoustic Michelin 18-inch tyres (designed to reduce road noise), a 360-degree camera system, manual rear sunblinds, three-zone climate control and one-touch ‘reset’ buttons for the middle-row seats.

Technology feels thoughtfully specified rather than excessive. There’s a 12.3-inch digital instrument cluster, wireless Apple CarPlay and Android Auto, Bluetooth connectivity and an eight-speaker Yamaha sound system. Charging and power options include six USB-A ports, one USB-C port, a 12-volt socket and a 220-volt AC outlet. The 10.1-inch multimedia touchscreen looks larger than it is thanks to its housing, though it ultimately sits on the smaller side for a vehicle pitching itself at the luxury end of the market.

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.
 

Both M8 grades share the same plug-in hybrid powertrain, pairing a 2.0L, four-cylinder, turbo-petrol engine with a single electric motor. Combined, they produce up to 274kW of power and 630Nm of torque which is impressive on paper, though it only manages 0‑100km/h in 8.8 seconds. Once the battery is depleted, outputs drop to a more modest 140kW/320Nm. Power is sent to the front wheels through a two-speed automatic transmission, and the M8 is not rated for towing.

To get the best performance from this type of set-up will require diligent recharging.

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.

The M8 is equipped with a Type 2 CCS charging port, accepting up to 6.6kW on AC and 39kW on fast DC power. Being able to use a DC charger is a definite plus for a plug-in hybrid and you can charge the battery on this type of charger from zero to 80 per cent in around 30 minutes.

Its 25.57kWh lithium-ion battery is generous for a plug-in, delivering an electric-only range of up to 106km (WTLP). With a combined cycle (urban/extra-urban) fuel consumption figure of 6.1L/100km and a 56L fuel tank, the M8 offers an overall driving range of more than 1000km which is excellent for a vehicle of its size. As with any plug-in, regular charging is key to achieving these figures; over my week of driving, I averaged 6.2L/100km, which is very excellent.

GAC recommends a minimum 91 RON unleaded petrol.

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.

Around town, the M8 delivers plenty of power and is whisper-quiet when running in electric mode. Once the battery depletes or you switch over to the petrol engine, that sense of instant oomph fades. Overtaking on hills is achievable, but even with an empty car it can feel a little underwhelming.

Steering is light, but the car feels solidly planted in most situations. Handling isn’t as dynamic as a Kia Carnival and the M8 can feel a touch ungainly through bends, though it’s more than manageable for everyday driving.

Ride comfort is high, especially for passengers, due to forgiving suspension and a cabin that doesn't let a whole lot of road or wind noise in. The M8 is a comfortable cruiser.

Visibility is surprisingly good for a 5.2m-long vehicle with minimal blind spots from the driver’s seat. The bonnet and dash, however, stretch further than they appear, which can make judging the nose a little tricky at first.

Ground clearance is only 143mm, so it’s easy to scrape the nose over speed bumps or when parking. The 360-degree camera system is decent, but manoeuvring into tight spaces still requires some care as it fills out a space. You also have to leave about a metre of clearance behind you if you want to open the tailgate.

The M8 hasn’t been tested with ANCAP yet and is unrated but it has a good suite of safety equipment including seven airbags with the curtain airbags covering all three rows but unique for the class is another airbag across the rear windscreen. However, it misses out on a front centre airbag., which is a strange omission now.

Standard equipment includes big-ticket systems like blind-spot monitoring, autonomous emergency braking, forward collision warning, lane keeping aid, lane departure warning, traffic sign recognition, rear cross-traffic alert and a clear 360-degree view camera system with front and rear parking sensors.

There is a sound alert and driver seat vibration that activates for some systems which I found to be a good addition. There’s also four ISOFIX child seat mounts (two in each rear row) and a total of five top-tether anchor points. While the M8 has adaptive cruise control, it’s not well-calibrated and creates a middling on-road experience.

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.

The GAC M8 is backed by a seven-year, unlimited-kilometre warranty, along with five years' complimentary roadside assistance, which is competitive against several of its nearest rivals. Service pricing has yet to be confirmed, though servicing is scheduled at 12-month or 15,000km intervals.

For now, the service network is limited, with around 10 centres nationwide, though GAC offers authorised servicing through third-party providers such as MyCar, which helps broaden access in the short term.