REVIEW | Plush Mercedes-Benz GLS 450d is a fuel-sipping adventurer

The Mercedes GLS range, otherwise known as the S-class of SUVs, recently arrived in South Africa boasting a facelift and engine upgrades.

Behind a more striking radiator grille and more prominent bumper of the updated range, the new GLS 450d model is powered by a straight six 3.0l diesel engine with outputs of 270kW and 750Nm, an upgrade over the previous 243kW and 700Nm made by the previous 400d. Paired with a nine-speed automatic transmission, it has snipped 0.2 seconds from the 0-100km/h sprint (now 6.1 seconds) while top speed stays the same at 250km/h.

Priced at R2,323,337 including a two-year/unlimited mileage warranty and five-year/100,000km maintenance plan, the GLS 450d is a more fuel efficient alternative to the Mercedes GLS 580 which is powered by a petrol V8 and sells for R2,876,669.

The diesel may lack the fiery 380kW output of the petrol version but doesn’t fall short on the performance front.

A new mild hybrid 48V EQ Boost system provides an additional intermittent boost of 15kW/200Nm, which contributed to the big Benz’s lusty overtaking power which we used frequently on the “gauntlet of a thousand coal trucks” N2 from Ermelo to Pongola on a road trip to Mozambique. The road is in bad shape from all the truck traffic due to our railways being in a mess, and apart from its ability to whisk past behemoths, the Merc’s bump-soaking Airmatic air suspension helped us traverse the long, scarred road with some semblance of sanity.

Airmatic adjusts automatically to driving conditions, speed and load. It is also height adjustable at the touch of a button to increase ground clearance for off-roading and lower the vehicle for ease of access or loading the boot. The 4Matic all-wheel drive system, standard on all GLS models, has an electronically controlled multiplate clutch that allows a variable transfer of drive torque from 0%-100% between the axles.

Refinement is of the top order, as you’d expect from a luxury Mercedes, and the GLS wafts along in near silence underlaid by a surprisingly sporty but muted undertone from the diesel engine. A mysterious intermittent knocking from the rear upset the otherwise quiet reverie, however.

An optional E-Active Body Control system uses fully active suspension to compensate for pitch, roll and shocks, and the ability to “bounce” the GLS out of trouble should you get stuck in deep sand or mud. The test car didn’t have this feature but we never needed it when driving offroad. With its tyres partially deflated as a precaution, the GLS easily sauntered over the soft, sandy road that made up the last few kilometres to our destination in Mozambique.

With all-wheel drive and the air suspension raised to its full height, the big SUV drove over the squishy turf without any wheelspin and never felt like it would get stuck. To keep you from thumping into hidden tree stumps, the 360° camera has a “transparent bonnet” function that uses the infotainment screen to show a virtual view under the front of the vehicle. 

Rocky trails might present more of a challenge to the low-profile road tyres fitted, but the GLS isn’t really pitched as a vehicle for hard-core off-roading. It’s more of a luxury Sandton pavement climber with the ability to take on the occasional gravel adventure, and at this it excels.

The vehicle also has no spare wheel, just a tyre repair kit, which could cause consternation when out in the wilds a long way from civilisation.

On the 10-hour trip between Joburg and Ponta Malongane the GLS revealed thoughtful touches including twin sun visors for the front seats so the driver and front passenger can simultaneously shade their front and side views. When you park, the “Hey Mercedes” voice assistant helpfully announces when you’ve left your phone in the car.

A panoramic sunroof, USB charging ports in all three rows, and hands-free tailgate are among the standard luxuries you get for R2.3m, and so too space — plenty of it. At 5,207mm long the Mercedes is slightly larger than its main rival, the 5,151mm BMW X7, and takes up to seven passengers in three rows of electrically adjustable seats.

Using buttons in the boot, the second and third rows electrically fold down to liberate an enormous 2,400l loading area. We had the third row folded flat and five passengers on board, and the boot swallowed our big stack of holiday luggage. An easy entry function electrically folds the middle row forward to access the rearmost two seats, which are ideally suited to children but spacious enough for two adults at a squeeze.

There is a functional mix of digital and analogue controls in the car, though I wasn’t fond of the finicky haptic volume adjusters on the steering wheel. As part of the GLS update, the MBUX infotainment system has a new look for the displays, which can be individualised with different styles and colour schemes in conjunction with the ambient lighting. 

What cemented my liking of this large luxury SUV is its low fuel thirst. Despite being laden like a farm mule, the big Benz sipped an impressively thrifty 8.5l /100km on the road trip, and the 90l tank ensures a real-world range of more than 1,000km.

The Mercedes GLS 450d ticks the boxes of an opulent, terrain-capable family SUV that doesn’t rapidly drain the fuel budget.