2020 Mercedes-Benz GLS First Drive Review: The SUV That Thinks It's An S-Class

Mercedes-Benz is on an SUV rampage. After unveiling the sleek GLC crossover and GLB compact SUV, we now have the all-new iteration of the full-size GLS-Class SUV. However, this is not my first encounter with Mercedes' new SUV. The Mercedes-Benz GLS made a splashing debut at the 2019 New York International Auto Show and impressed me with its S-Class levels of refinement, build quality, and premium technology.

The 2020 Mercedes GLS is the third-generation model of the German carmaker's biggest and most luxurious SUV. As is so often the case, the GLS is marginally larger than the SUV it replaces. Compared to other luxury SUVs like the Range Rover LWB and BMW X7, the new GLS has a longer wheelbase. In fact, it has a 2.4-inch longer wheelbase than that of the old GLS.

Larger dimensions is a godsend for a family SUV. Since you're trying to compensate for the passenger room in a minivan, the third-row seating is usually an afterthought in most large SUVs. Not so in the 2020 Mercedes GLS. The increase in length and girth means more livable space in the row furthest back.

It may not look like it, but the seats there are actually spacious enough for larger adults, although taller individuals will prefer the room offered in the second row. Still, the third row get real seats – not just the thinly-padded varieties you find in other so-called seven-seat SUVs – and Mercedes says they were designed for people up to 6'4" tall. Being 6'2" myself, I can attest that the second and third row are more than adequate for longer trips. And, in order to make life easier, the third-row seats are heated and occupants get their own USB charging ports because, well, this is the S-Class of SUVs we're talking about here, right? If maximum seating isn't your first priority, the GLS can be specified as six-seat variant, with a pair of captain's chairs for the second row.

In terms of styling, the new Mercedes GLS has a more organic and flowing shape than the outgoing model. Despite this, Mercedes was able to infuse the GLS with some off-road styling DNA to give it a more purposeful stance. The powerful front end is flanked by an upright, octagonal radiator grille. The massive hood has a pair of power dome bulges to hint at the innovative and powerful powertrain laying underneath.

Also obvious is the prominent chrome-plated under-guard cover beneath the front bumper, with large bone-shaped air inlet grilles. The headlights are multibeam LED units that Mercedes says have 112 LEDs per headlamp: they produce the maximum light intensity permitted by law, which casts a bright light within a range of 650 meters or 2,000 feet. Because if you're riding in an S-Class SUV, you need to outshine the Audi and BMW competition.

Viewed from the rear, the new GLS is unmistakably a Mercedes. The LED taillights seem like they were shaped by the muscular shoulders in the rear profile of the vehicle, which gives it a distinctive stance. Despite the sleeker and rounded rear profile, however, there's no mistaking the GLS is a big vehicle. The size and ruggedness are further defined by the chrome-plated under guard in the rear bumper.

Despite the added heft, the new Mercedes GLS achieves an impressive 0.32 Cd in wind tunnel testing. The previous model GLS only achieves 0.35 Cd by comparison. Admittedly, the difference is minuscule, but this is enough to limit wind noise and improve fuel economy over the outgoing model. Mercedes has yet to reveal the official EPA numbers of the new GLS-Class, but I'm assuming it'll sip less fuel due to the advanced, electrified powertrain.

And now we get to the juicy bits. Large, three-row SUVs need an equally large and powerful motor to counteract the mass. Mercedes obliged by giving the GLS-Class a new pair of motors. The GLS 450 comes with a turbocharged 3.0-liter inline six producing 362 horsepower and 369 pound-feet of torque. The GLS 580 is equipped with a twin-turbocharged 4.0-liter V8 with 483 horsepower and 518 pound-feet of torque. Both rely on a nine-speed automatic and 4MATIC all-wheel-drive system powering all four wheels as standard.

What's really special is the integration of Mercedes' EQ Boost mild-hybrid system on both engines. As we saw in the Mercedes-AMG CLS 53 Coupe, EQ Boost consists of a small electric motor nestled between the engine and transmission and a small battery pack. The former also functions as an integrated starter-generator. The system outputs an additional 21 horsepower and 184 pound-feet of torque over short periods. The EQ Boost system also generates power for the onboard 48-volt electrical system, which in turn powers the air-con compressor and water pump to reduce engine load.

All the engine power is fed to the standard 4MATIC all-wheel drive system to give the GLS true off-road conquering abilities, and I mean this in every sense of the word conquering. That being said, despite the talented AWD system with an electronic transfer case and multi-plate clutch, the new Mercedes GLS-Class is not a mountain goat, taking on its bigger AMG G 63 brother.

Instead, it's about predictability and safety, no matter the traction conditions you might be facing on the road. The updated 4MATIC AWD system sends 100-percent of the torque to the rear wheels in normal driving. If the system detects slippage, it can distribute 50-percent of the available power to the rear wheels. This automatically-varying drivetrain is good on both paved and unpaved roads.

On the way to the off-road section, the journey there and back was as delightful as the off-road adventure itself. Faced with demanding surfaces such as loose sand, dirt, and gravel, the new GLS allowed me to drive a massive 7-seater SUV in ways that it really wasn't meant to be driven. Steering input into tight switchbacks – where drop off could result in catastrophic injuries and maybe even death – aren't the usual fare for a sizable truck. Yet, here I was with a high level of confidence that things will be just fine.

The turn-in radius rivals competitors with rear wheel steering, leaving you with superbly precise steering on or off the road. Then again, buyers don't buy the GLS for off-roading, so I get to do it and report back that it's highly capable should you ever need to. The GLS 580 goes further by offering an optional off-road tuned transfer case and reduction gear for those tricky trails, so it's good to know the GLS is ready for the rough stuff as needed.

The biggest reason for considering the new GLS, though, is the S-Class ride quality. It's essentially the S-Class in the form of an SUV. If you've never been in an S-Class before, the ride can only be described as excellent, cosseting, and refined. It's smooth and yet doesn't float at the slightest provocation.

Adaptive air suspension is standard in the new Mercedes GLS, but you need the optional 48-volt E-Active Body control system if you want the ultimate in comfort, sportiness, and off-road capabilities in a single package. The active and predictive suspension system utilizes a camera to literally read the road surface ahead. It then primes the dampers to counteract the suspension motion as the vehicle traverses over bumps.

It even has a curve function that allows flat cornering with almost zero centrifugal force. Yes, this is probably the most complicated suspension system ever fitted to a family SUV, but it works unerringly well to flatten out potholes and other road imperfections.

While the active suspension soaks up the bumps, the interior ensconces the occupants in luxurious comfort as well. Everything you can see, touch, and feel are of premium quality. The haptic and audible touch controls have a solid and sturdy feel like in a well-made smartphone.

The cabin is filled with a combination of rich leather, exquisite wood, and metallic elements to convey a feeling of modernity and new age luxury. The MBUX infotainment system dominates front and center with two large 12.3-inch screens. The system recognizes voice and gesture commands, while the driver gets to enjoy a full-color heads-up display.

The new Mercedes-Benz GLS starts at $75,200 for the GLS 450 4MATIC. This includes the turbocharged inline-six EQ boost powertrain and a long list of standard equipment including 19-inch wheels, 64-color ambient lighting, Apple CarPlay & Android Auto, a Burmester surround sound audio system, and the MBUX infotainment with voice control. The GLS 580 includes the twin-turbo V8 and EQ Boost powertrain and starts at $97,800.

The 2020 Mercedes-Benz GLS is everything we're expecting from a flagship German SUV. It provides a luxurious, spacious, and comfortable mode of conveyance that won't back down at the slightest hint of unpaved roads. Mercedes set out to make the S-Class of SUVs, but it ended up with something even more special than that.