Mercedes-AMG GLS 63 S 2021 Review

Apparently, a German environmental group nominated the Mercedes-AMG GLS 63 S for something called the Golden Vulture award.

Basically, they contended the latest SUV from Benz’s hot tuner was a perfect example of what vehicle not to build in a time of climate crisis.

They might have a point. The new second-generation GLC 63 is 5.243m long, 2.03m wide, 1.782m high and weighs in at a staggering 2555kg.

Its 4.0-litre V8 engine claims to consume 13 litres of premium petrol every 100km and expel nearly 300 grams of CO2 per kilometre. Those figures are higher in the real world. Trust us.

And it costs $255,700 plus on-road costs. That, by the way, is a $35,000 hike over its predecessor.

Now that wallet-walloping price isn’t the most you’ll pay for an SUV in Australia – not even an AMG SUV (the G-Class is slightly more expensive).

There are several Range Rovers and versions of the Bentley Bentayga that are much more costly, as well as the Lamborghini Urus, Aston Martin DBX and even the hideous and hideously expensive Rolls-Royce Cullinan.

So in that company the Mercedes-AMG GLS 63, with its flexible seven-seat capacity, looks almost like the sensible choice.

No surprise at this price the GLS 63 is loaded down with gear; hey, the standard GLS range it’s based on isn’t exactly pauper pack material anyway.

Externally, the GLS is given away by its giant version of the AMG krill-muncher grille, power domes on the bonnet, chunky bumpers and lots of blacked out bits (called the Night Package).

It also rolls standard on 22-inch alloy wheels, although the test car was fitted with $3900 optional 23s shod with staggered Michelin Pilot 4S rubber. And, yes, there is a temporary spare in the boot.

Inside, there’s swathes of Nappa leather trim, ionised and filtrated air, a flat-bottom AMG steering wheel, an extended MBUX (Mercedes-Benz User Experience) package, heating of just about any part of your body that touches a seat and even temperature-controlled cup holders.

Stuff the 63 shares with other GLS models include a 13-speaker Burmester sound system, five-zone climate control, all the standard MBUX infotainment features spread across the spectacular widescreen cockpit, wireless charging for mobile devices and Apple CarPlay and Android Auto integration.

Naturally, all seven seats in the 2-3-2 layout are powered. There’s even a button in the boot that collapses or raises all seats in row two and three simultaneously. Right next to it is a button to lower ride height to aid loading.

The GLS 63 is protected by a five-year/unlimited-kilometre warranty. Service intervals are every 20,000km or one year. A three-service plan costs $3050, a four-service plan $4000 and a five-service plan $4550.

There’s no shortage of safety equipment fitted to the Mercedes-AMG GLS 63 S, but there is also no ANCAP rating either. That’s not surprising considering the independent safety body focuses on mainstream vehicles.

There are no less than nine airbags, including curtains that stretch back to protect row three occupants.

There are lots of active driver assist systems led by autonomous emergency braking (AEB). But this vehicle can also steer by itself, actively stay in its lane, read speed signs and warn of crossing traffic. Hands-off driving is possible for a few seconds at a time before the car gets cranky with you.

Other safety aids include LED headlights, a head up display, parking assistance including a 360-degree camera and tyre pressure monitoring.

The Mercedes-AMG GLS 63 S shares its core Modular High Architecture (MHA) with the cheaper GLS models as well as the smaller Mercedes-Benz GLE.

From that base, AMG has deviated down its own high-performance path, starting with the M177 V8 under the bonnet. With its turbochargers mounted within the vee, the DOHC 32-valve engine has done sterling service in an array of models.

While it produces a mighty 450kW and 850Nm, the drivetrain in the GLS 63 S (and the GLE 63 S that arrived at the same time) features a 48-volt mild-hybrid system that briefly mixes in extra power and torque to boost performance. Max inputs are 16kW and 250Nm, although it’s not necessarily all available as it is also used to run auxiliary systems.

Still, it all helps the GLS achieve a remarkable 4.1sec 0-100km/h time and a 280km/h top speed.

But the mild-hybrid system also saves fuel via coasting and stop/start functions, while the engine features cylinder deactivation too. Hate to think how thirsty this thing would be without those features, as we averaged 15.6L/100km on test.

The M177 drives via an AMG-tuned nine-speed torque-converter automatic transmission and a rear-biased 4MATIC+ all-wheel drive system that’s topped off by a locking differential on the rear axle.

The suspension system includes adaptive air springs and dampers and active roll stabilisation, the latter activated electronically rather than hydraulically. AMG says this makes it respond to inputs more quickly.

The steering is also a variable-ratio speed-sensitive AMG set-up, while braking is provided by massive 400mm discs and six-piston callipers up front and 370mm discs and single floating callipers at the rear.

The driver is able to tailor the drivetrain, chassis, assist systems and more via modes for both on- and off-road driving. An individual mode allows personalisation.

Braked towing capacity is 3500kg, so no problems towing a Taj Mahal on wheels! But worth noting the factory towing pack is a $1900 option.

As pointed out already, the Mercedes-AMG GLS 63 S is a very big vehicle. Considering all that, AMG really deserves to be commended for the way it drives.

No, it doesn’t ‘shrink wrap’ around you or feel ‘connected’ as really outstanding sporting drives do. Instead, it’s just impressive that it is as cohesive as it is for its bulk.

The active anti-roll bars have to get some credit for that. The GLS retains body control without the suspension settings wound up so tight the GLS becomes a buckboard on rough roads.

Hey, I wouldn’t recommend Sport+ for anything but smooth surfaces, but wound back from there the ride is good enough in Comfort to be family-friendly, and focused enough in Sport to tackle a winding road.

But the more open and flowing that road is the more you and the GLS will enjoy it.

Considering the weight of the GLS, the engine response is astonishing. From a lazy V8 murmur in the background when pottering, it awakens with metallic valvetrain gnashing and a howl from the sports exhaust when the throttle is pressed. A bang-crackle on the over-run is delicious when you lift off.

Like the chassis, the drivetrain never becomes impossibly focused as you dial up through the modes. If you want hyper response from the transmission, then manual changes via the flappy paddles are the go. No manual lever changes of course, as the GLS has a column shifter like most current Benzes.

There’s no palpable throttle lag and no easing off in the rush forward until well beyond 6000rpm. That’s where those massive brakes come in and thankfully do their job.

Your brake pad bill has the potential to be substantial. Tyres too. But don’t go skimping, the GLS benefits enormously from top-notch rubber.

Back in commuter central, the GLS does fine. Its hushed cabin, refined behaviour and relaxed gait make it suitable for the day-to-day drive in peak hour traffic where you can enjoy that great sound system.

Shopping centres and other tight car parks are not fun working with a 13.1m turning circle. But the view out is panoramic and there are sensors and cameras to help avoid unintended contact.

As you would expect, the GLS 63 is a classy place to reside. But it’s not uber-luxury. It’s more techno than traditional. Those two 12.3-inch screens on the dashboard make a huge statement.

Customisation opportunities are myriad and drilling into menus seems to go on endlessly. Control can be exerted by touch, voice or click wheel.

A shortcut that allowed the quick cancellation of steering and lane keep assist was appreciated. Like so many of these systems, their tune in the GLS is too intrusive.

The front sports seats are excellent, the middle pews flatter but are still expansive and, yes, you can fit adults in row three. But I wouldn’t recommend it for a long drive.

Storage options, USB-C outlets, air-con vents and drinks holders abound. This is a vehicle that’s designed to transport you and your passengers in greater comfort.

And your luggage too, as capacity starts at 355 litres and expands all the way to a mammoth 2400L.

It turns out the 2021 Mercedes-AMG GLS 63 S is not only big when it comes to the facts and figures, it’s also got a quite sizeable personality.

Plaudits to AMG for proving a 2500kg, 5.2m-long SUV can actually be quite enjoyable to drive. But also for not trying to make it something it’s not.

In its default Comfort mode this vehicle is an everyday driver that looks a lot tougher than it really is.

But the price and the huge and obvious consumption of resources is definitely off-putting. In all honesty, those German environmentalists probably have a point.

How much does the 2021 Mercedes-AMG GLS 63 S 4MATIC+ cost?
Price: $255,700 (plus on-road costs)
Available: Now
Engine: 4.0-litre twin-turbo V8 petrol
Output: 450kW/850Nm
Transmission: Nine-speed automatic
Fuel: 13.0L/100km (ADR Combined)
CO2: 296g/km (ADR Combined)
Safety rating: Not tested

Related reading:
Mercedes-AMG GLE 63 S and GLS 63 2020 International Review
LA MOTOR SHOW: Mercedes-AMG GLE and GLS 63 unpacked
Mercedes-Benz GLS 400d 2020 Video Review
New Mercedes-Benz GLS priced
Mercedes-Benz GLS-Class: FAQs