Mercedes-AMG has dropped a comprehensively revised 4.0-liter V8 biturbo into the 2027 GLE 63 S and GLS 63, bringing 603 hp and 627 lb-ft to its performance SUV lineup. The M177 EVO engine arrives with a flat-plane crankshaft, second-generation mild hybrid hardware, and revised exhaust aftertreatment engineered to meet tightening global emissions standards without sacrificing the output buyers expect from an AMG V8. Both models reach U.S. dealerships in fall 2026.
The flat-plane crank is the substantive engineering change. Mercedes-AMG swapped the traditional cross-plane design for a flat-plane configuration that reduces rotating mass, sharpens throttle response, and allows the engine to rev more freely. Power holds at 603 hp, matching the outgoing M177, but torque delivery spreads across a wider band: 627 lb-ft from 2,500 to 4,500 rpm. The second-generation integrated starter generator adds 23 hp and 151 lb-ft at lower engine speeds, recuperates energy during deceleration, and smooths start-stop operation through the 48-volt electrical system.
Performance figures land where AMG’s V8 SUVs have historically landed. The GLE 63 S runs 0-60 mph in 3.6 seconds; the larger, heavier GLS 63 in 3.9 seconds. Both are electronically limited to 174 mph. The M177 EVO is hand-built in Affalterbach under the one-man, one-engine philosophy AMG has used since the division’s performance-engine program began.
The engineering updates extend beyond the crankshaft. AMG revised the intake camshaft, redesigned intake and exhaust ports, optimized the fuel injection system, and improved the compressor wheel and turbocharger housing. A particulate filter is now standard worldwide, part of the exhaust aftertreatment package that allows the engine to meet current emissions regulations in markets where the previous M177 would no longer qualify. Michael Schiebe, chairman of the management board of Mercedes-AMG, framed the updates as future-proofing: the M177 EVO secures the V8’s presence in the AMG portfolio for the long term.
The front fascia is new. AMG fitted a redesigned radiator grille, enlarged air intakes to feed the V8’s cooling requirements, and LED headlamps with an exclusive AMG light signature. The rear diffuser and twin tailpipes of the AMG Performance exhaust system define the back end. The exhaust system itself is newly developed, with valve control that adjusts sound from subdued in Comfort mode to fully open in Sport+. Sound profile changes with the selected AMG DYNAMIC SELECT drive program or via a button on the center console.
AMG RIDE CONTROL+ air suspension with adaptive damping is standard. The system offers continuously variable damping control that shifts between a firm Sport setting for track-focused dynamics and a compliant Comfort setting for highway driving. In Trail mode, ride height increases by 2.2 inches for off-road work, with damping control, AMG Active Ride Control, and the 4MATIC+ all-wheel-drive system recalibrated for low-traction surfaces. When the driver selects Sport or Sport+, ride height drops by 0.4 inches. At speeds above 75 mph in Comfort mode, the suspension lowers by 0.4 inches to reduce drag and improve stability.
AMG ACTIVE RIDE CONTROL active roll stabilization is standard on both models. Electromechanical stabilizers on both axles analyze the driving situation and road surface 1,000 times per second, compensating for body roll in real time. The system reduces roll effects to a minimum when cornering or driving over uneven surfaces, and it improves stability off-road. The electronically controlled AMG locking rear differential distributes torque between the rear wheels based on grip conditions, reducing slip at the inside wheel without braking intervention.
The wheel catalog extends to 22 inches for the GLE 63 S, including a new 22-inch AMG forged cross-spoke wheel in Tech Gold. The GLS 63 offers options up to 23 inches: a new multi-spoke design and a five-spoke monoblock wheel, both emphasizing the vehicle’s scale. Inside, the latest-generation AMG Performance steering wheel is available in Nappa leather, microfiber, or microfiber-carbon fiber combinations. AMG DRIVE UNIT steering wheel buttons provide direct access to performance functions. Interior upholstery runs from Black, Macchiato Beige, Beech Brown, and Red Pepper Nappa leather to MANUFAKTUR Yacht Blue, Tartufo Brown, and Carmine Red options.
The MANUFAKTUR program adds paint finishes including Cirrus Silver Magno, Patagonia Red Metallic, Mystic Blue Metallic, Moonlight White Metallic, Alpine Grey, Moonlight White Magno, Silicon Grey, Côte d’Azur Light Blue Metallic, and Ireland Mid Green Metallic. The AMG Night Package Plus with dark chrome accents is optional. The new MB.OS operating system displays AMG-specific performance data on high-resolution screens: torque distribution, G-forces, and detailed engine parameters.
Competitive context is straightforward. The BMW X5 M, Porsche Cayenne Turbo, and Range Rover Sport SVR occupy the same high-performance luxury SUV segment as the GLE 63 S. The GLS 63 sits in the full-size three-row category, where performance variants are less common. Mercedes-AMG has not disclosed pricing for either model. The flat-plane V8 and the regulatory compliance work behind it suggest the M177 EVO is positioned as a multi-year solution, not a placeholder ahead of electrification. Whether buyers prioritize that longevity over the plug-in hybrid and electric options now available from BMW and Porsche will shape how these models perform once they reach showrooms this fall.
2027 Mercedes-AMG GLE 63S and GLS63 Photo Gallery
Source: Mercedes-Benz. Images courtesy of Mercedes-Benz.
