REVIEW | The 2020 Mercedes GLS is an all-terrain limousine

The offroad limousine segment is a rarefied one, and if you want a luxury all-terrain vehicle with three rows of seats some of the pinnacle contenders include the BMW X7, Bentley Bentayga and the vehicle on test here: the Mercedes-Benz GLS.

The GLS is dubbed the S-class of SUVs and the new third-generation version fits the bill. It offers more comfort and luxury and space than its predecessor, having grown in size to more comfortably fit up to seven passengers. 

At 5,207mm long this hulk is even larger than its main rival, the 5,151mm BMW X7. The Benz isn’t as overtly flashy as the Beemer and its giant grille, but still carries a lot of imposing gravitas behind its three-pointed star. Taking one look at its sheer size and heavily tinted rear windows, one passenger remarked that it looked like a mafia-mobile.

Humans aboard the GLS, mafioso or otherwise, will find it an impressively comfortable and refined experience. Air suspension with adaptive damping provides a wonderfully cushy ride, even on rough dirt and pothole-scarred tar, and the ride height can be set for tar or off road work at the flick of a switch.

They’ll find it sumptuous too as the vehicle whisks them along in a cocoon of silent luxury, with external sounds muted out to whisper levels. Opulence and technology are laid on thick in the roomy cabin, which sports the latest Mercedes MBUX infotainment as part of its digitised setting.

MBUX rear entertainment and a high-end Burmester audio system are optionally available to turn the cabin into a concert hall, and you’ll also pay extra for features such as keyless operation, power-closing doors, panoramic sliding roof, trailer manoeuvring assist, head-up display, massaging seats and active cruise control, to name a few.

Standard fare includes electrically adjusted seats in all three rows, ensuring all passengers can fine-tune their individual comfort settings and also making easy work of folding the seats when extra loading space is needed. With buttons in the boot, the second and third rows can be quickly folded down to open up a panel van-sized 2,400l loading area.

An easy entry function electrically folds the middle row forward to facilitate passenger entry into the back row. The rearmost seats accommodate a pair of adults in reasonable comfort, and have USB charging ports just like the front two rows.

Ticking the options box gets all three rows of seats heated and cooled. 

The vehicle comes with three engine choices: the GLS 580 turbo petrol V8 with outputs of 360kW and 700Nm, the fire-breathing GLS63 AMG version with a 450kW/850Nm V8 4.0 petrol turbo, and the subject of this test, the GLS 400d with a 3.0l six-cylinder turbo diesel.

With 243kW and a mighty 700Nm of torque this big SUV feels like a lighter ride, as evidenced by its ability to sprint from rest to 100km/h in a sprightly 6.3 seconds. It feels strong all the way through the rev spectrum, with spirited overtaking prowess and effortless cruising ability.

It’s refined too, with little aural evidence that it sips the darker fuel; in fact it makes a subtly sporting growl that’s quite pleasant. At under 11l /100km the diesel GLS is fairly thrifty for such a giant, even though it never came close to the factory-claimed 7.9l.

At 2.5 tons it will never feel sporty in the corners but with the air suspension in its low setting the body roll isn’t as extreme as it could be, and you can push this behemoth reasonably hard through bends before the wheels start squealing. 

If you want it feeling like a smaller and lighter car, you can order the optional E-Active body control for R114,000 (not fitted to the test vehicle) which uses fully active suspension to compensate for pitch, roll and shocks. It includes a Curve function to make the vehicle lean into bends in a similar way to motorcyclists, to minimise centrifugal force.

Also optional is an Off-Road Engineering package for R33,300 which includes a fully-variable all-wheel drive system with low range, and an underguard for the entire underbody.

The test vehicle didn’t have this latter package but nevertheless managed to scramble through Gerotek’s bumpy off-road course with relative ease.

With the air suspension lifted to its maximum height the big Benz kept its undersides out of harm’s way, and hill descent control ensured slow and safe passage down steep gradients.

The all-wheel drive combined with electronic stability control generally kept forward momentum going without incident, though axle-twisters sometimes paused the vehicle in its tracks when one or more wheels lifted off the ground. Still, the GLS eventually made it through.

As part of the optional E-Active package, the vehicle has a novel feature: it can use the air suspension to bounce itself up and down to help extract itself from sand or mud — simpler than fiddling with a tow rope or a winch, I reckon.

In summary, the S Class of SUVs is an overachiever that packs a lot of vehicle into a single R1.78m package: it’s a quiet, luxurious seven-seater offroad limousine that can tackle tar and trails with equal ease.

But it will need to be specced up to around R2m to take advantage of some of its best new features.

_{Tech Specs}

_Engine

_{Type: Six-cylinder diesel turbo}

_{Capacity: 2,925cc}

_{Power: 243kW}

_{Torque: 700Nm}

_Transmission

_{Type: Nine-speed auto}

_Drivetrain

_{Type: 4Matic all-wheel drive}

_Performance

_{Top speed: 238km/h}

_{0-100km/h: 6.3 seconds}

_{Fuel Consumption: 7.9l/100km (claimed); 10.9l /100km (as tested)}

_{Emissions: 208g/km}

_{Standard features}

_{Active lane keeping, blind spot monitor, park assist with 360° camera, active brake assist, nine airbags, stability control, air suspension with adaptive damping, multibeam LED headlamps, ABS brakes, climate control}

_Ownership

_{Warranty: Two years/unlimited km}

_{Service plan: Five years/100,000km}

_{Price: R1,787,600}

_{Lease*: R38,075}

_{* at 10% interest over 60 months no deposit}

_Competition

_{BMW X7 xDrive 30d, 195kW/620Nm — R1,742,958}

_{BMW X7 M50d, 294kW/760Nm  — R2,068,386}

_{Motor News star rating}

_{Design * * *}

_{Performance * * * *}

_{Economy * * * *}

_{Safety * * * * *}

_{Value For Money * * * *}

_{Overall * * * *}