Mercedes-Benz GLS 2020 450 4matic (hybrid)

2020 Mercedes-Benz GLS450 long-term review: Introduction

$128,950 $153,340 Dealer
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It's the biggest Mercedes by a square mile – probably because it takes up as much space!
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The boss. The top dog. The grand poobah. The big enchilada.

When it comes to being the king of the hill in the premium SUV stakes, nothing comes close to a big Mercedes. Or in the case of our 2020 Mercedes-Benz GLS450 long-termer, the ‘biggest’ Mercedes.

Like a rolling solar eclipse, at 5219mm long by 2030mm wide, the GLS casts a shadow larger than the BMW X7 (5151mm x 2000mm), the Audi Q7 (5063mm x 1970mm), and the Land Rover Discovery (4970mm x 2073mm).

It takes up more square-metreage (10.6m²) than the old GLS (9.9m²), the slab-sided G-Class (9.8m²), the X-Class ute (10.3m²), the V-Class van (9.9m²), even the long-wheelbase Maybach S-Class (10.4m²)! Bottom line, if you want a bigger ’Benz, you had better start shopping for a Unimog.

No wonder they call it the 'S-Class of SUVs'.

2020 Mercedes-Benz GLS450
Engine configurationInline six-cylinder turbocharged petrol (with 48V mild-hybrid)
Displacement3.0L (2999cc)
Power270kW @ 5500rpm (+16kW EQ-Boost)
Torque500Nm @ 1500–4500rpm (+270Nm EQ-Boost)
Transmission9-speed (9G-Tronic) automatic
Drive typeAll-wheel drive
Weight (Tare)2656kg
Power to weight ratio101.7kW/t
0–100km/h claim5.2sec
Fuel consumption (combined cycle claim)9.2L/100km
Fuel consumption (combined cycle on test)-
Fuel tank size90L
Turning circle12.01m
Sales categoryUpper-Large SUV (premium)
Key competitorsBMW X7 / Audi Q7 / Land Rover Discovery

Priced from $147,100 before options and on-road costs, the petrol ’450 undercuts its high-compression 400d stablemate by $6800 ($153,900) for what is an identically specified car. Worth considering, too, if you’re choosing the diesel just to pay less at the pump, it will take you about 20 years to make up the difference...

Fuel-type comparisons aside, the ’450 is packing a 3.0-litre turbocharged inline six-cylinder petrol engine mated to a 48-volt mild-hybrid system. This gives the GLS a regular output of 270kW and 500Nm, but with an extra 16kW and 250Nm available as a short-burst ‘EQ-boost’.

A nine-speed automatic transmission and constant all-wheel drive are standard, as is variable-height air suspension. Our car goes a step further and adds the $13,000 E-Active Body Control function with the auto-levelling ‘Curve’ function and the 'forward-looking predictive-adaptive dampening adjustment technology', which I prefer to simply call ‘the speed hump eraser’.

A camera in the windscreen scans the road ahead, and when it spots a bump, it tells the car to adjust the compression rate of the suspension to compensate. You hear the thump, and the car sort of moves around, but if you get all the parameters working in the right way, it can feel as though there was nothing there. It's not perfect, but it's still very impressive.

2020 Mercedes-Benz GLS450
Ground clearance199mm (adjustable)
Boot volume355L / 890L / 1470L (2040L to roof)
Tare mass2656kg
Tow rating (unbraked / braked)750kg / 3500kg
Wheels/tyres22-inch – 285/45R22 front, 325/40R22 rear Continental

We’ve also got the $2500 Night Package, which adds black trim elements, a body styling kit and those enormous yet strangely proportional 22-inch alloy wheels, and the $800 Interior Innovation package for adaptive lighting and augmented-reality navigation. Add in the $2100 Selenite Grey Metallic paint (one of 10 choices), and the SS GLS sets sail for $165,500 plus on-road costs.

For context, and perhaps yet another hint at the size of the GLS, that makes it about $15,613 per square metre, which is cheaper than buying land in Coogee. And remember, you can’t drive a house!

Speaking of which, inside the cavernous GLS is seating for seven, with all rows featuring powered seats and USB charge points. The boot expands from an A-Class-sized 355L with all seats up, to 890L as a five-seater and 2400L to the roof with everything down. You can fold the seats individually or as a ‘set’ with the touch of a button near the boot door, plus there’s even room for a space-saver wheel and a place to keep the cargo blind under the boot floor.

Leather trim is naturally standard, as are heated, ventilated, massage and memory seats in the front. You score quad-zone climate control, soft-close doors, the twin 12.3-inch LCD displays, a 13-speaker Burmester sound system, voice-activated ‘Hey Mercedes’ digital assistant and onboard connected telemetry and communication via MercedesMe.

Even all this is barely scratching the surface of what the GLS has up its voluminous sleeve.

2020 Mercedes-Benz GLS450
ColourSelenite Grey Metallic
Price (MSRP)$147,100
Options as tested$18,400
Servicing 3yr$2700
Servicing 5yr$5200
ANCAP safety ratingNot yet tested
Warranty5 years / unlimited km

So what’s the plan while we have it?

First and foremost, the question begs: Is the GLS too big for the urban environment? To find out we’ll do the shopping, the school run, and all manner of urban errands. We’ll see what it’s like to park and manoeuvre, and see whether the ‘clearly designed with the North American market in mind’ size and shape of the big Merc’ works within inner Melbourne.

Then we’ll explore the long-distance touring capability of the GLS and see how well the inline-six chews up highway miles in terms of fuel economy and air-riding comfort. Does the mild-hybrid system do anything to offer meaningful improvement in terms of consumption or performance, or is it just there to support the myriad electrical functions of the car?

A long drive will allow us to explore whether the active ‘Curve’ driving mode works in a 2656kg family-hauling SUV, and how well the air-ride cossets Australia’s less than billiard-smooth roads.

Finally, and aligned to the above point, we’ll take a good look at all the technology on offer – from the all-digital dash to the comfort and convenience features, through to the connectivity functions of MercedesMe. Does throwing the full catalogue of Benz’s tech and luxury at a giant box make the GLS worthy of the ‘S-Class of SUVs’ moniker?

So strap in, stretch out, get comfortable, and be sure to ask us anything you would like to know about the grandest 'G' on the block, the 2020 Mercedes-Benz GLS450. In the meantime, I’ll crank up some Jurassic Five on the Burmester and request a hot-stone massage for the driver’s seat – anything to help your car-buying research!