It is remarkably easy to get all rhapsodic about Mercedes-AMG’s newest flagship, the GLS 63. Its finely crafted, cavernous cabin, its generous three rows accommodating six or seven occupants, and its bold, head-turning style—highlighted by towering 23-inch rims and a striking new illuminated grille—are certainly noteworthy. Yet, in essence, the true appeal of this high-performance luxury sport utility vehicle lies entirely beneath the hood, where a profound mechanical evolution has taken place.
For the 2027 model year, Mercedes-AMG has extensively redesigned its signature 4.0-liter twin-turbocharged V-8 engine. It now pumps out a formidable 603 horsepower and 627 foot-pounds of torque. That immense muscular output is more than enough to hurl this 6,110-pound heavyweight from a complete standstill to 60 miles per hour in a blistering 4.0 seconds, a feat aided considerably by a newly implemented launch-control feature.
This upgraded power plant is part of Mercedes-AMG’s new-generation M177 EVO family, enhanced and enlivened by a flat-plane crankshaft—a performance architecture traditionally reserved for shrieking, high-revving supercar engines. According to engineering briefings from AMG, this sophisticated design successfully lowers internal mechanical mass, delivers sharper, more immediate throttle response, and makes the V-8 significantly more eager to climb through the rev range. Beyond raw performance gains, the revised configuration also assists the automaker in meeting increasingly stringent global vehicle emission regulations.
Even if this more potent engine were not enough to command attention, the 2027 Mercedes-AMG GLS 63 bristles with fresh technology and engineering upgrades designed to sharpen its overall driving dynamics. It also arrives with a more distinctive exterior appearance and even higher levels of interior luxury. Together, these enhancements give this latest high-performance GLS a wider berth to stand out convincingly from rival three-row performance SUVs, such as Cadillac’s Escalade-V, BMW’s X7 M60i, and Audi’s brand-new SQ9.
What’s New
The current-generation design language of the GLS 63 has been a familiar sight on roads since 2020. Consequently, industry observers should think of this latest iteration as a midlife facelift, albeit an exceptionally thorough one, with a reported 40 percent of its components being entirely new. For starters, it presents a much bolder visage to the world. It adopts a fresh, Panamericana-style grille featuring vertical chrome bars that pay explicit homage to the legendary 1952 Mercedes 300 SL race car, which famously competed in the grueling Carrera Panamericana road race across Mexico.
Exterior lighting has also been comprehensively updated. The GLS 63 now features a striking ring of bright-white LEDs encircling the larger, thicker-framed grille. Enlarged headlights incorporate clever, three-pointed-star running lights, while newly designed taillights integrate multiple three-pointed stars as a cohesive signature design motif.
Down at the rear, an aggressive new AMG Performance exhaust system features a quartet of ovoid tips poking menacingly out of a revised lower rear diffuser. At all four corners, buyers will find fresh rim designs, including a sophisticated 23-inch multi-spoke wheel and a distinctive five-spoke 23-inch monoblock option that evokes classic AMG heritage.
Stepping inside reveals a heavily redesigned dashboard layout, elevated further by the brand’s expansive, full-width MBUX Superscreen. This digital architecture comprises a trio of 12.3-inch displays, including a dedicated screen for the front-seat passenger. Operating this technology is the new MB.OS operating system, which features vastly enhanced "Hey Mercedes" voice recognition commands backed by advanced AI internet searches and fully integrated Google Maps navigation. Reassuringly, amidst the sea of digital glass, Mercedes has retained plenty of tactile physical buttons for core functions.
Drivers are greeted by a wonderfully thick-rimmed AMG steering wheel available in a choice of premium coverings. Naturally, the German automaker’s expanding Manufaktur customization program provides an extensive palette of new upscale interior materials and upholstery choices. Less universally appreciated, however, is the somewhat theatrical neon ambient cabin lighting, which can give the interior an aesthetic reminiscent of Tokyo by night if adjusted to its highest intensities.
Design
The full-bodied GLS 63 remains the largest physical model in the ever-expanding fleet of Mercedes SUVs. Measuring over 206 inches from nose to tail, it is still slightly shorter than Audi’s new SQ9, which stretches to 209 inches, and the massive Cadillac Escalade-V, which measures 212 inches. Nevertheless, standing a towering 70 inches tall, observers will never mistake it for anything other than an absolute automotive behemoth.
Yet, thanks to the latest exterior design revisions, it carries a more distinct and purposeful presence than ever before, especially when rolling on those massive 23-inch wheels. Exclusive AMG styling cues further heighten its intimidating on-road footprint. These signature elements include a heavily contoured, power-domed hood, a bolder front fascia featuring significantly enlarged lower air intakes, and striking new paint colors such as Mid-Green Metallic, Moonlight White Magno, and Mystic Blue Metallic.
Powertrain and Hardware
While the new M177 EVO V-8 undeniably anchors the GLS 63’s performance credentials, a suite of advanced hardware works behind the scenes to back it up. This includes sophisticated mild-hybrid technology centered around a new-generation integrated starter-generator. At lower engine operating speeds, this system contributes an additional 23 horsepower and 151 foot-pounds of torque. While it does not offer pure electric-only driving capability, its true purpose is realized in sharper off-the-line responsiveness and a remarkably smooth refinement of the automatic stop-start function.
To ensure this large Mercedes corners with as much competence as it exhibits in a straight line, the GLS 63 is equipped with AMG Active Ride Control+ active-roll stabilization. This system actively counters body roll through tight corners, yielding remarkably stable and precise handling characteristics. It operates in tandem with the vehicle’s standard air suspension, which can automatically raise the ride height by 2.2 inches when venturing off the beaten path. Furthermore, the adaptive damping system delivers a firm ride quality when left in Comfort mode, and progressively firmer settings when switching into Sport or Sport+ modes, successfully keeping unwanted body motion tightly controlled.
Performance
For an automobile tipping the scales at over 6,000 pounds, the comprehensive array of AMG performance upgrades transforms the GLS 63 into an astonishing thrill to drive. Straight-line acceleration is nothing short of explosive. The new AMG exhaust system, combined with the V-8’s flat-plane-crankshaft design, produces a sharp, urgent soundtrack—one entirely uncharacteristic of a traditional SUV—as the engine marches steadily toward its 6,800-rpm redline.
This is a sensational engine possessing immense character, offering endless low-end and midrange muscle for effortless passing maneuvers, alongside surprisingly smooth, refined high-speed cruising capability. Dialing up Sport or Sport+ via the console-mounted drive-mode selector awakens a palpable reservoir of raw energy.
Naturally, physics dictates that an object weighing upwards of 3,000 kilograms and standing nearly six feet tall will never handle quite like a low-slung sports car. However, the GLS 63 puts forth an admirable effort, utilizing an electronically locking rear differential to effectively transmit all 603 horsepower straight to the pavement. The steering is commendably well-judged; while it initially feels slightly light at low speeds, it quickly reveals itself to be wonderfully precise and communicative.
The primary compromise for this level of athletic prowess is a consistently firm ride quality, even when the suspension is set to Comfort mode. The sticky Michelin Pilot Sport 4S tires provide phenomenal mechanical grip, but they also generate a fair amount of road noise in the cabin, and severe potholes demand careful attention and avoidance at all costs.
Is It Worth It?
Arguably, the most formidable challenges facing this latest GLS 63 come from within Mercedes-Benz’s own product portfolio. Many performance-minded buyers might find complete satisfaction in the exceptional GLS 580, which utilizes a variant of the 4.0-liter V-8 and still produces a very muscular 530 horsepower. Alternatively, for drivers willing to forgo third-row seating entirely, the lighter, more compact, AMG-tuned GLE 63 features the exact same 603-horsepower engine setup in a smaller package.
However, for discerning buyers who specifically require three functional rows of seating, luxury accommodations, and the capability to tow up to 7,700 pounds of heavy equipment or recreational trailers, this Mercedes-AMG GLS 63 delivers a visceral performance experience that fully justifies its starting price of approximately $157,000.
