2020 Mercedes-Benz GLS 400d review

We’re not suggesting you need to be a man to handle this supersized Benz GLS. It might be big but it’s no beast; rather it’s a gentle giant.

The proliferation of SUVs shows no sign of abating, and high riders will dominate the Mercedes-Benz showroom this year. While the mix for other brands is already well skewed toward the SUV, M-B passenger sales here have been around the 60/40 car to SUV ratio for the past few years, thanks to an appreciation of the C-Class and a helping hand from the A-, E- and CL- ranges.

Things are set to change in the new decade as Mercedes-Benz will have nine different SUVs to choose from, giving it the largest range of high riders on the market. Expect the new GLA and GLB to join the just-refreshed GLC, the GLE and this, the new GLS. Add the coupe versions of the GLC and GLE, the G Glass and the EQC, and Benz has the bases pretty well covered for shoppers in the premium SUV space.

Now in its third generation, the GLS has grown bigger still as it’s all about ‘pushing the boundaries and making a statement’. It’s now 77mm longer at 5207mm and 60mm has been added to the wheelbase, all to advance interior accommodations. Why buy such a thing you might wonder? They tell us that seven seats is a drawcard, while it’s a decent tow wagon as well with a 3500kg braked capacity from its $1900 tow package. And then there are those who simply must have the biggest. Folks looking for an XL luxo carryall will find the GLS fits the (expensive) bill.

All seven seats aboard GLS are electrically adjustable and the second row offers plenty of width, making three abreast possible without feeling uncomfortable, and there’s decent legroom too. Though not quite as much as offered by the X7 we reckon. Access to the rear is made easy as the second row seat (split 40/60) slides and tilts out of the way at the touch of a button. Those rearmost pews are genuinely adult friendly, with enough comfort and space for six footers, providing the second row is slid forward a smidge to free up legroom. The powered operation of the seats is convenient but does take a few moments, while each row has its own zone of air con and plenty of USB charge points. With all seats in place, there’s a usable 355L of boot space, more than in an A-Class. In five-seater mode, there is 890L, thanks mainly to the length of the hold, and with all seats folded (there’s a button for that too, all five rear seats lowering or raising at once) there’s 2400L in full van mode.

So it’s a genuinely practical seven seater, and suitably luxurious too. The cabin is finely trimmed and finished no matter where one sits, the front row lined in leather (or leather-like Artico), wood and double-stitched luxury with plastics banished to the footwells alone. There’s just about every conceivable comfort and convenience feature present with massaging and ventilated seats as standard.

These offer superb comfort with a wide range of adjustment. Other bits include a head-up display, power closing doors, a big 12.3-inch screen, CarPlay and AA, and a wireless charger. There’s no compromise on safety with everything Mercedes-Benz has to offer. Control of some of the interior functions can be handled by the ‘Hey Mercedes’ MBUX system, while others require some shuffling through the menus. There are enough buttons to help but there’s just lots to learn. The cabin is light and airy thanks to a bigger panoramic sunroof, and the fitment of beige trim. It’s not the most serviceable colour, but does lend the cabin a more inviting ambience than the default black. Brown is another option.

Just one model is offered initially, the 400d, with a base price of $166,700. The AMG Line styling pack is standard, giving it a sporty look as that’s what most want. Still you can add more, this one with the Night Package ($2500) which adds black detailing, and a few more AMG styling elements, while the 23s, the biggest wheel fitted to a Merc yet, are $2100. The $800 Innovation Package adds further functionality for the MBUX system, and also augmented reality for the sat nav. This uses the front camera to relay your surroundings to the main screen when you approach a turn or intersection, highlighting more clearly the street you need to take and also your intended destination address. If you’re a frequent sat nav user, it’s worthwhile and will impress your passengers.

The new straight six diesel in the 400d cranks out 243kW with 700Nm, enabling a 0-100km/h time of 6.3sec (we were 0.4 adrift however) and is rated at 7.7L/100km. We averaged in the high nines, still okay given this is a sizable wagon. There’s a nine-speed auto, permanent AWD and adaptive and height adjustable air suspension.

When pressed, the body movements tend toward wayward in Comfort, but control comes in Sport mode, the air springs managing to sort the bumps without excess harshness. The rocking and rolling is minimal, and the front sticks well when cornering with more vigour, the steering accurate but a filter for sensation. The GLS disguises its mass up to a point and the brakes sure feel all that weight after a while.

It’s a hushed highway cruiser, claimed aeros of 0.32 probably helping, while the six is super-quiet, churning at 1300rpm by 100km/h. Yet it has plenty in the tank come time to overtake, the auto kicking down swiftly, the engine spinning strongly to 4500rpm to tap the power but it’s the abundant surge that makes this engine, pulling strongly from below 1500rpm, and steaming mad by 2000rpm. Yet it’s always quiet, refined, and relatively frugal.

The ride on the 23s is not as polished. For the most part, this rides well without feeling too wafty or aloof, but it doesn’t manage to isolate the stuff you really don’t want to feel, like a proper luxury limo would. If your image can stand it, maybe stick with the standard-fit 21s.

While big, it’s not overwhelmingly so. The turning circle is sizeable but the steering is light and the excellent surround camera helps you line up those parks, some of which are a squeeze due to its girth. There’s self parking too, which is quick in operation and docks this in spaces you’d not likely attempt yourself. The active cruise’s stop and go function in traffic could be smoother on the halts, and the engine’s idle stop function is quick on the refires, though the six does awaken with a jolt. It’s about the only time you do notice the engine, apart from when the full force of the 700Nm hits. Its response and outputs are such you’ll rarely feel the need to shift into the Dynamic driving mode.

Others to consider include the X7, if you can stand the look of that grille, the Discovery if you want more off-road ability, or the XC90 if you want to spend a lot less. But given the added space, glitz and tech, we expect the GLS will continue to be a popular seller here.