The Mercedes-Benz GLS occupies a unique and demanding space in the automotive landscape. As the brand’s largest SUV, it carries the heavy responsibility of serving as the S-Class of the utility vehicle lineup. Following the recent W223 S-Class refresh—which introduced sweeping updates to styling, powertrains, and technology—it is now the turn of the GLS to undergo its second major facelift. Over recent weeks, a series of Mercedes SUV reviews have rolled out, starting with the heavily reworked 2027 Mercedes-Benz GLE, followed by the 2027 Mercedes-AMG GLE53 PHEV, and culminating in the flagship Mercedes-AMG GLS63.

While the non-AMG variants of the refreshed GLS family share identical styling and technological upgrades with their smaller GLE siblings, the GLS63 remains the crown jewel of the lineup. It is a vehicle that embodies contradiction: utterly ridiculous, entirely pointless, and yet undeniably magnificent.

Mercedes invited automotive media to the scenic mountains of Colorado to evaluate its refreshed 2027 GLE and GLS lineups. Placed in a cozy cabin in the woods and treated to local mountain cuisine, reviewers were given the opportunity to sample the diverse array of flavors across both model families, with the GLS63 standing out as an exercise in high-performance excess.

Second Facelift’s the Charm

This update marks the second time Mercedes has refreshed its full-size flagship SUV, bringing its exterior styling in line with the brand’s latest design language. The most striking visual modifications are found up front, where the GLS adopts an illuminated, star-studded aesthetic. The daytime running lights feature a slightly more subtle star-shaped motif than the bolder layout seen on the GLE, but each headlight assembly incorporates two stacked three-pointed stars. These elements are tied together by a controversial black plastic grille surround, a stylistic hallmark of Mercedes’ newest generation of vehicles.

At the rear, the design theme continues with taillights that discreetly hide three three-pointed stars within each housing, linked across the tailgate by another strip of high-gloss black plastic. Automotive aesthetics remain deeply subjective, and while the updates modernize the vehicle, the cleaner, more understated appearance of the outgoing GLS generation retains a certain classic appeal for traditionalists.

Beneath the surface, the broader GLS lineup benefits from powertrain refinements borrowed from the GLE. The entry-level GLS450 is powered by a turbocharged 3.0-liter inline-six engine paired with an upgraded, more powerful mild-hybrid system that includes an electric auxiliary compressor. Maximum torque increases by 44 pound-feet to reach a total of 413 lb-ft, while horsepower remains steady at 375. The 2027 GLS450 starts at $95,500, including destination charges, and is already arriving at dealership showrooms nationwide.

Moving up the ladder, the V8-powered GLS580 adopts the new M177 Evo twin-turbocharged 4.0-liter V8 engine featuring a flat-plane crankshaft. This powerplant generates 530 horsepower and 553 lb-ft of torque, enabling the SUV to accelerate from 0 to 60 mph in an estimated 4.5 seconds. With a starting price of $122,500, the GLS580 is also currently available at dealerships.

Beyond powertrain updates, the GLS mirrors the equipment list of the GLE. It incorporates cloud-based air suspension damper controls, the optional E-Active Body Control air suspension, standard micro-LED Digital Light headlights, and next-generation driver assistance hardware. This advanced sensor suite is engineered to support point-to-point hands-free Level 2++ autonomous driving capabilities via future over-the-air updates, alongside an expanded array of cabin technology.

Would Sir Like More Screen?

Inside the cabin, the GLS adopts the architecture of the GLE, which includes the integration of the optional Mercedes Superscreen. This arrangement houses three individual 12.3-inch displays beneath a single continuous glass panel stretching across the width of the dashboard. The driver’s instrument cluster sits behind an AMG steering wheel equipped with physical roller controls for volume and cruise control, though the remaining steering wheel buttons frustratingly rely on touch-sensitive pads. While the steering wheel offers an exceptional grip and feel in the hands, the capacitive controls remain a point of frustration.

The 12.3-inch central infotainment screen inherits the ergonomic shortcomings observed in the GLE, primarily due to its squat aspect ratio. Given the vast expanse of glass on the dashboard, the central display feels comparatively small and narrow, bounded by prominent black bezels that detract from the seamless digital aesthetic. Operating the system is further complicated by the learning curve associated with the new MB.OS software interface.

The third display, positioned directly in front of the passenger, serves as a dedicated touchscreen. In AMG models, this screen provides access to active powertrain telematics, displaying real-time metrics such as instantaneous horsepower utilization—arguably the most engaging feature of the passenger display. Other functions duplicate what can easily be handled by a personal smartphone or tablet. Furthermore, the passenger screen lacks the interface capability to control seat massage functions or expanded seat adjustments. Passengers must reach across the center console to interact with the primary infotainment display to alter basic seat settings, representing a significant ergonomic oversight.

Because the underlying vehicle architecture dates back to 2020, the interior retains a row of physical climate control switches and a console-mounted touchpad. These legacy analog controls provide a welcome reprieve, making menu navigation through the infotainment system more manageable than relying exclusively on the undersized touchscreen. However, like the GLE, the cabin of the expansive GLS suffers from a surprising lack of small-item storage in the front row, save for the split-opening center armrest—a notable drawback for what is arguably Mercedes’ most family-oriented vehicle.

Familiar Power: 603 Horsepower and 627 lb-ft of Torque

At the absolute summit of the model hierarchy sits the AMG GLS63, powered by a hand-built, twin-turbocharged V8 engine that produces 603 horsepower and 627 lb-ft of torque. Although output figures remain identical to the previous model year, Mercedes engineers implemented internal revisions to the powerplant. The engine delivers a sensory experience defined by a sharp startup bark and a resonant roar under wide-open throttle. For the first time, the GLS63 features a launch control function—an admittedly excessive feature for a three-row family utility vehicle, but one that delivers undeniable thrills.

Though unstated by Mercedes-AMG, competitive pressures from vehicles like the Cadillac Escalade-V likely influenced development in Affalterbach. The Escalade-V utilizes a supercharged 6.4-liter LT4 V8 engine to produce a staggering 682 horsepower and 653 lb-ft of torque, complete with its own dramatic launch control soundtrack and acceleration profile, though the AMG remains the quicker of the two.

Activating launch control in the GLS63 follows the standard AMG protocol: selecting Sport+ drive mode, firmly depressing both the brake and accelerator pedals simultaneously, feeling the seatbelts cinch tight, and releasing the brake to unleash maximum acceleration. Mercedes estimates this 6,118-pound luxury hauler accelerates from 0 to 60 mph in 3.9 seconds, a figure that feels entirely accurate from the driver’s seat. In a straight line, the GLS63 behaves with the relentless velocity of a rocket sled.

It Still Wasn’t Perfect

The test vehicle featured a sophisticated color combination of Manufaktur Mystic Blue Metallic exterior paint over Truffle Brown Nappa leather, riding on optional 23-inch AMG forged multi-spoke wheels. It was also equipped with optional carbon-ceramic brakes, featuring massive 15.8-inch discs up front and 14.2-inch discs in the rear. During limited driving exposure, mastering the extremely grabby nature of the upgraded carbon-ceramic brakes proved challenging. Minimal pressure on the brake pedal routinely resulted in abrupt, seatbelt-locking deceleration, suggesting that buyers might prefer to skip this costly option, despite its immense stopping power.

Weighing in excess of 6,100 pounds, the GLS63 feels every bit its size and height out on the road. Navigating damp, winding mountain roads in Colorado highlighted the vehicle’s physical footprint. While body roll is remarkably well-controlled thanks to the standard AMG Ride Control+ air suspension and active roll stabilization, physics cannot be entirely rewritten. Even when wrapped in wide Michelin Pilot Sport 4S tires—measuring 285/40 up front and 325/35 in the rear—the SUV’s mass becomes apparent through tight corners and under heavy braking on wet surfaces, inspiring caution rather than flat-out confidence.

While a direct comparison between the GLS450, GLS580, and the AMG GLS63 was not possible during this drive program, the AMG badge guarantees a heightened level of dynamic tuning. The GLS63 undoubtedly offers a more composed and agile experience on dry pavement, but on greasy, leaf-strewn wet asphalt, its handling limitations were evident. Nevertheless, it achieves a level of athletic capability that far exceeds conventional expectations for a large three-row family vehicle.

The GLS63 Is Excessive, Ridiculous, Silly, and Cool Because of It

In the tradition of high-performance automobiles—particularly high-performance SUVs—the GLS63 is defined by pure excess. No driver objectively requires a 603-horsepower, three-row luxury transport capable of sprinting to 60 mph in under four seconds with a base price starting at $156,800 before options. Yet, it is precisely these outrageous performance metrics that grant the vehicle its unique appeal.

Purchasing a GLS63 is not a decision driven by pure logic; it is a choice made possible by substantial financial means. For buyers with the resources to acquire and fuel such a machine, it offers undeniable street presence, ensuring that school drop-off lines are met with immediate recognition. The flashy visual updates inside and out elevate the 2027 Mercedes-AMG GLS63’s profile to new heights, cementing its status as an unapologetic statement of automotive extravagance.