Mercedes-AMG unveils GLE 63 S and GLS 63 with flat-plane V8

Mercedes-Benz has unveiled updated high-performance versions of its GLE and GLS SUVs for the 2027 model year, headlined by a comprehensively redesigned V8 engine featuring a motorsport-inspired flat-plane crankshaft. The new Mercedes-AMG GLE 63 S 4MATIC, available in both SUV and Coupe body styles, and the larger Mercedes-AMG GLS 63 4MATIC mark the introduction of the new M177 EVO powertrain in these flagship models.

The core change is under the hood. The 4.0-liter twin-turbocharged V8 now uses a flat-plane crankshaft, a design more common in high-revving motorsport engines, which Mercedes-AMG says reduces rotating mass for sharper throttle response and improved efficiency. The engine produces 603 horsepower and 850 Newton-meters of torque, figures that match the outgoing model's output. It is paired with an updated 48-volt mild-hybrid system, whose integrated starter-generator contributes an additional 23 horsepower and 205 Nm of torque, primarily to enhance low-end response.

Performance remains formidable. The GLE 63 S can accelerate from 0 to 100 km/h (0-62 mph) in 3.6 seconds, while the larger GLS 63 achieves the same sprint in 3.9 seconds. Both models have an electronically...