M ERCEDES-BENZ has taken the automotive phenomenon of ‘segment creep’ to the extreme with its new GLS, stretching the large SUV by 77mm compared to the previous generation and bringing its total length to 5207mm. Of that extra length, 60mm has been added directly between the wheels, for a wheelbase of 3135mm.

Why? To make the GLS one of the most practical vehicles for carting a large number of people (and their luggage) this side of a people-mover. 

Powering the GLS is a choice of two 3.0-litre straight-six turbocharged engines, which send power to all four wheels via a nine-speed automatic transmission. The GLS 450 starts the two-variant range at $146,500, powered by an M256 petrol engine with EQ boost (fancy speak for a mild-hybrid system) providing total outputs of 270kW/500Nm.

However, it’s the $153,300 GLS 400d that we have on test, powered by the OM656 diesel, with claimed outputs of 243kW and 700Nm – sizeable increases of 53kW and 80Nm compared to the second-gen GLS 350d it replaces.

This is expected to be the more popular variant, and acceleration is claimed to be a crisp 6.3 seconds to 100km/h – impressive considering the nearly 2.5-tonne weight of the vehicle.

Behind the wheel it’s easy to forget you’re driving a diesel, with nary a hint of the old oil-burner clichés present. It’s just the lowly redline that gives the game away, and that prodigious low-end torque. The ninespeed ’box shuffles between gears subtly, without constantly searching for the right ratio when you lay into the throttle.

Air suspension is standard, with Merc engineers reworking the front axle design in an effort to reduce tyre noise and vibrations. As a result, damping is well sorted, the ride plush and cosseting, with impressive body control. In terms of broader dynamic ability, the GLS is able to be hustled at a pace that defies its imposing physical stature.

The cabin is hushed at cruising speeds, with impressive refinement keeping noise intrusion from wind and road to a minimum.

The dimensional expansion hasn’t been in vain, with the GLS offering supreme space inside for both animate and inanimate cargo. Second-row seats can slide fore and aft, with up to 87mm of legroom offered, which is extremely generous.

Boot space is, frankly, vast. Even with the third row of seating raised, there’s 355 litres of luggage space, growing to 890 litres with just two rows being used. These are increases of 60 and 210 litres respectively compared to the previous-generation GLS.

Despite its almost six-metre length, the big Benz isn’t unwieldy, with an admirable 12.5-metre turning circle, and enough parking cameras and sensors to land a lunar module.

The GLS has a towing rating of 3500kg, but you’ll need to fit the optional $1900 towbar package before you hitch a wagon to the rear. If you are a bit of a bitumen-dodging masochist, you can also tick the box for the $3500 off-road package.

Options like these could raise the price of the GLS even further above its rivals. This is the Mercedes’ only real downfall, with higher pricing compared to BMW’s X7 and Audi’s Q7. But for the way GLS pairs practicality with luxury and driving dynamics, that price premium may be money well spent.


Model Mercedes-Benz GLS 400d

Engine 2925cc 6cyl, dohc, 24v, turbo-diesel 

Power 243kW @ 3600-4000rpm 

Torque 700Nm @ 1200-3000rpm 

Transmission 9-speed automatic 

Weight 2490kg 

0-100km/h 6.3sec (claimed) 

Economy 7.7L/100km 

Price $153,300 

On sale Now   


Ride; dynamics; space; engines


Entry price; cost of some options

Pack it up

AMG Line styling is standard in Australia. This is the first Merc which can be fitted with 23-inch wheels from the factory; our test vehicle came with 22-inch rims as part of the $2500 Night Package styling option, wrapped in meaty Continental Premium Contact 6 rubber – 285/45/22 at the front, and 325/40/22 at the rear. The GLS goes big on functionality, too. A switch is easily accessible at the boot which lowers the rear of the car, and each seat can be electronically raised or lowered individually. The spare wheel in the boot can be accessed even with all three rows of seats being used.