Mercedes-AMG has revealed the 2027 GLE 63 S and GLS 63, and the headline story is a fundamentally reengineered V8. The updated M177 EVO engine retains its 4.0-liter displacement and 603 hp output, but underneath those familiar numbers is a significantly reworked unit — one built to stay relevant in an era of tightening global emissions rules while delivering sharper throttle response than before. Both models arrive at U.S. dealerships in fall 2026.
The GLE 63 S Coupe reaches 60 mph in an estimated 3.6 seconds; the larger GLS 63 follows at 3.9 seconds. Both are electronically limited to 174 mph. Those numbers aren’t dramatically different from the outgoing cars, but the engineering path to get there has changed considerably.
A Flat-Plane Crankshaft Changes The Character Of AMG’s V8
2027 Mercedes-AMG GLE 63 S CoupeMercedes-Benz
The most consequential change inside the M177 EVO is the switch to a flat-plane crankshaft. In a traditional cross-plane V8, the crankshaft’s throws are offset at 90-degree intervals, which smooths low-frequency vibrations but adds rotating mass. A flat-plane arrangement spaces the throws at 180 degrees instead — reducing that mass and allowing the engine to spin up more freely. The result is quicker rev response and a more eager character at higher engine speeds, closer in feel to what you’d expect from a smaller-displacement engine.
AMG pairs the new crank with optimized fuel injection, redesigned intake and exhaust ports, a revised intake camshaft, and improvements to the compressor wheel and turbocharger housing. Peak torque of 627 lb-ft is available across a broad band — 2,500 to 4,500 rpm — and the engine meets stringent worldwide emissions standards through updated exhaust aftertreatment that includes a particulate filter fitted as standard globally.
ISG 2.0 Mild-Hybrid Fills In The Low-End With 151 lb-ft
2027 Mercedes-AMG GLE 63 S CoupeMercedes-Benz
Complementing the revised V8 is a new-generation integrated starter generator — AMG’s ISG 2.0 — operating on a 48-volt electrical system. The ISG isn’t a traditional hybrid system; it doesn’t power the wheels independently. Instead, it acts as a torque-fill device, contributing up to 23 hp and 151 lb-ft at lower engine speeds where a turbocharged V8 typically takes a moment to build boost. The effect is a smoother, more immediate response off the line and at partial throttle. The system also handles recuperation during deceleration and manages the start/stop function seamlessly.
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Suspension And Drivetrain Keep The SUV Planted
2027 Mercedes-AMG GLE 63 S CoupeMercedes-Benz
Both models ride on AMG Active Ride Control+ air suspension with adaptive damping. The system continuously adjusts to road conditions and selected drive mode, dropping ride height by 0.4 inches in Sport and Sport+ for a lower center of gravity, and raising it by 2.2 inches in Trail mode for light off-road work. AMG Active Ride Control active roll stabilization adds electromechanical stabilizers on both axles, with sensors reading road and chassis inputs up to 1,000 times per second to minimize body roll in corners.
Power reaches all four wheels through AMG Performance 4MATIC+ all-wheel drive with fully variable torque distribution, paired with a nine-speed AMG Speedshift TCT transmission. A standard electronically controlled locking rear differential distributes torque between the rear wheels without braking intervention, preserving momentum during hard cornering and improving traction in slippery conditions.
New Exhaust, Revised Styling, And Broad Personalization
2027 Mercedes-AMG GLS 63Mercedes-Benz
The AMG Performance exhaust system is newly developed for these models. Adjustable exhaust valves let the driver dial in sound character through AMG Dynamic Select — from a subdued note in Comfort mode to a more pronounced V8 voice in Sport+. The front end has been redesigned with a new AMG-specific radiator grille, enlarged air intakes, and LED headlamps carrying an exclusive AMG light signature. Twin tailpipes and a characteristic diffuser define the rear.
Wheel choices run up to 22 inches on the GLE 63 S — including a new 22-inch AMG forged cross-spoke in Tech Gold — and up to 23 inches on the GLS 63, which gains two new designs: a multi-spoke and a five-spoke monoblock. Inside, the latest AMG Performance steering wheel is offered in Nappa leather, microfiber, or a carbon fiber combination, and the new MB.OS operating system displays torque distribution, G-forces, and engine data on high-resolution screens. The Manufaktur program expands the exterior palette with new finishes including Cirrus Silver Magno and Patagonia Red Metallic for buyers who want something beyond the standard color range.
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TopSpeed’s Take
2027 Mercedes-AMG GLE 63 S Coupe & GLS 63Mercedes-Benz
The 2027 GLE 63 S and GLS 63 make a clear case that AMG’s V8 has more runway ahead. The flat-plane crankshaft and mild-hybrid combination addresses the two things buyers most notice — throttle feel and low-speed response — while the emissions compliance work ensures the engine can continue in markets with the strictest regulations. For performance SUV buyers, that’s a meaningful combination of engineering substance and long-term reassurance.
Source: Mercedes-Benz
