It is remarkably easy to get thoroughly rhapsodic about Mercedes-AMG’s newest high-performance flagship, the GLS 63. Its meticulously crafted cabin, its versatile three-row seating capable of accommodating six or seven occupants with ease, and its bold, head-turning road presence commanded by towering 23-inch rims and a striking new illuminated grille are all instantly noteworthy. Yet, beneath the exquisite upholstery and the imposing exterior sheet metal, the true essence and ultimate appeal of this high-performance sport utility vehicle lie entirely within its beating heart: a heavily revised, motorsport-derived engine.
For the 2027 model year, Mercedes-AMG’s renowned 4.0-liter twin-turbocharged V-8 has undergone a comprehensive redesign. It now pumps out an astounding 603 horsepower and 627 foot-pounds of torque. That is more than enough muscle to punch this 6,110-pound heavyweight from a complete standstill to 60 miles per hour in just 4.0 seconds, a blistering feat aided significantly by a newly implemented launch-control feature.
This formidable power plant is Mercedes-AMG’s new-generation M177 EVO, a unit enhanced and enlivened by a flat-plane crankshaft—a mechanical feature traditionally associated with the shrieking engines of exotic supercars rather than family-capable luxury haulers. According to AMG engineers, this architecture successfully lowers internal reciprocating mass, delivers a markedly sharper throttle response, and makes the V-8 significantly more eager to rev up to its redline. Furthermore, this advanced engineering helps the heavy-duty luxury vehicle meet increasingly stringent global emission regulations without sacrificing its signature aggressive performance characteristics.
If this significantly more potent engine were not quite enough to turn heads, the 2027 Mercedes-AMG GLS 63 bristles with fresh technology and advanced engineering enhancements designed to sharpen its driving dynamics even further. It also arrives with a much more distinctive exterior design language and an even higher level of luxury embedded throughout its cavernous cabin. Collectively, these comprehensive updates give this latest hot-rod GLS ample room to stand out prominently from rival three-row performance SUVs, such as Cadillac’s formidable Escalade-V, BMW’s refined X7 M60i, and Audi’s brand-new SQ9.
What’s New
The current generation of the GLS 63 has been a fixture in the luxury performance segment since 2020, meaning automotive enthusiasts should view this latest iteration as a midlife facelift—albeit an exceptionally significant one, with a reported 40 percent of its total components being entirely new. Visually, it looks considerably bolder right out of the gate. It adopts a fresh, Panamericana-style grille featuring vertical chrome bars that pay direct homage to the historic 1952 Mercedes 300 SL race car, which famously competed in the grueling Carrera Panamericana road race across Mexico.
The exterior lighting array has also been thoroughly modernized. There is a new ring of bright-white LEDs encircling the larger, thicker-framed grille, while the enlarged headlights now incorporate striking three-pointed-star running lights. At the rear, fresh taillights likewise boast the iconic three-pointed-star motif integrated directly into their operational design.
Looking lower down at the rear fascia, observers will spot a newly styled AMG Performance exhaust system featuring a quartet of ovoid tips poking aggressively out of a revised rear diffuser. At all four corners, drivers can choose from newly designed wheels, including a commanding 23-inch multi-spoke version alongside a distinctive, heritage-inspired 5-inch 23-inch monoblock option.
Step inside, and the cabin immediately reveals a redesigned dashboard enhanced by the automaker’s expansive, full-width MBUX Superscreen. This setup deploys a trio of 12.3-inch displays, including a dedicated screen for the front-seat passenger to manage navigation or entertainment. Complementing this hardware is the advanced new MB.OS operating system, which features enhanced "Hey Mercedes" voice recognition capabilities backed by AI searches and seamless Google Maps integration. Reassuringly, amidst the digital shift, Mercedes has retained plenty of tactile physical buttons for primary controls.
The interior is further elevated by a thick-rimmed AMG steering wheel available in a variety of premium coverings, alongside an expanded array of upscale materials sourced directly from the automaker’s bespoke Manufaktur program. The only stylistic misstep in an otherwise breathtaking cabin is the inclusion of an overly vibrant, neon ambient lighting configuration that can occasionally lend the interior the distinct aesthetic of Tokyo by night.
Design
The full-bodied GLS 63 comfortably retains its crown as the largest model within the ever-expanding fleet of Mercedes SUVs. Measuring over 206 inches from nose to tail, it remains somewhat shorter than Audi’s new SQ9, which stretches to 209 inches, and Cadillac’s mammoth Escalade-V, which measures 212 inches. Nevertheless, standing a full 70 inches tall, drivers and onlookers alike will never mistake it for anything other than an absolute automotive behemoth.
Yet, thanks to the latest exterior design revisions, the vehicle possesses a more distinctive road presence than ever, particularly when rolling on those oversized 23-inch wheels. AMG-exclusive exterior cues further amplify its commanding posture, including a muscular, power-domed hood, a bolder front fascia featuring enlarged lower air intakes, and a palette of striking new paint colors such as Mid-Green Metallic, Moonlight White Magno, and the Mystic Blue Metallic seen on launch vehicles.
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 a sophisticated mild-hybrid system featuring a new-generation integrated starter-generator. At lower engine speeds, this electrical architecture supplements the combustion engine with an additional 23 horsepower and 151 foot-pounds of torque. While it does not offer any capability for pure electric-only driving, its primary mission is successfully accomplished: boosting off-the-line responsiveness and smoothing out the operation of the automatic stop-start system.
To help the substantial Mercedes corner with the same level of competence it demonstrates in a straight line, the GLS 63 is equipped with AMG Active Ride Control+ active-roll stabilization. This system actively works to reduce body roll during aggressive cornering, resulting in remarkably stable and precise handling. It operates in tandem with a standard air-suspension system that can elevate the vehicle’s ride height by 2.2 inches when venturing onto uneven terrain. Meanwhile, the adaptive damping system delivers a firm ride quality when left in Comfort mode, and progressively firmer settings when switching to Sport or Sport+, rewarding the driver with significantly reduced body movement during spirited maneuvers.
Performance
For an automobile that tips the scales at over 6,000 pounds and stands nearly six feet tall, the comprehensive array of AMG performance enhancements transforms the GLS 63 into a genuine thrill to pilot. Straight-line acceleration is nothing short of exhilarating, while the combination of the new AMG exhaust system and the V-8’s flat-plane crankshaft architecture produces an urgent, aggressive soundtrack that feels entirely uncharacteristic of a traditional SUV as the engine winds toward its 6,800-rpm redline.
This is a sensational engine brimming with character, offering endless low-end and midrange muscle for effortless passing maneuvers, alongside surprisingly smooth and refined high-speed cruising manners. Dialing up Sport or Sport+ via the drive-mode selector unlocks an immediate surge of kinetic energy.
Naturally, nothing weighing upward of 6,000 pounds will ever handle precisely like a low-slung sports car, but the GLS 63 makes a remarkably valiant effort. Its electronic-locking rear differential is exceptionally effective at putting all 603 horsepower down onto the asphalt, while the well-weighted steering setup—while initially feeling slightly light—proves to be remarkably precise and communicative.
The primary compromise for this level of athleticism is an uncompromisingly firm ride quality, even when the suspension is set to Comfort mode. The sticky Michelin Pilot Sport 4S rubber provides phenomenal levels of mechanical grip, but it also translates into a noticeable degree of road noise inside the cabin, and deeply rutted potholes are best avoided entirely.
Is It Worth It?
Arguably the most significant market challenges facing this latest GLS 63 come from within the Mercedes family itself. Many performance-oriented buyers might find complete satisfaction in the exceptional GLS 580, which utilizes a similar 4.0-liter V-8 architecture and still pumps out a highly muscular 530 horsepower. Alternatively, for buyers willing to forgo third-row seating entirely, the lighter, more compact, AMG-tuned GLE 63 shares the exact same 603-horsepower output in a smaller footprint.
However, for drivers who specifically require three rows of passenger seating alongside a robust capability to tow up to 7,700 pounds of heavy boat trailers or race-car haulers, the Mercedes-AMG GLS 63 delivers a visceral, high-performance driving experience that fully justifies its starting price of approximately $157,000.
