For those questioning whether a complex powertrain can enhance or hinder a vehicle’s performance, the Mercedes-Benz GLC 63 S offers a definitive answer within mere minutes of driving. Beneath the surface lies a sophisticated system, yet its operation is remarkably seamless, translating to an exceptionally intuitive driving experience. The GLC boasts a comprehensive suite of driving modes – Comfort, Electric, and three performance-focused options: Sport, Sport+, and Race. Each mode meticulously adjusts parameters such as throttle response, stability control, suspension calibration, and steering effort, allowing drivers to tailor the vehicle’s character to their specific needs and preferences.
Electric mode functions exactly as expected, prioritizing all-electric driving and keeping the gasoline engine dormant. Comfort mode, the default setting, operates as a sophisticated hybrid system, intelligently engaging and disengaging the engine based on various driving conditions to optimize efficiency and performance. Conversely, the Sport modes maintain continuous gasoline engine operation, which also serves to actively recharge the GLC’s battery, ensuring readily available power when needed. Regardless of the selected mode, the GLC responds instantly when the accelerator is fully depressed, delivering its full power reserves. However, in Electric or Comfort modes, there’s a brief pause, approximately one second, for the gasoline engine to activate and contribute its power, but once engaged, the combined output is substantial and readily accessible.
The acceleration in the GLC 63 S is characterized by its smoothness and linearity. Drivers will appreciate the absence of any noticeable transitions between electric and combined gasoline-electric power delivery. This seamless integration is a significant advantage, particularly when considering that some plug-in hybrids can feel underpowered when relying solely on electric propulsion. To illustrate, the Toyota Prius Prime, in Edmunds testing, accelerated from 0 to 60 mph in 6.9 seconds in hybrid mode, but this figure dropped to a considerably slower 10.8 seconds when using only the electric motor. The GLC 63 S avoids this pitfall. Even in electric-only mode, it provides ample power (201 hp and 236 lb-ft of torque) for confident city driving and effortless highway passing maneuvers.
While formal testing is pending, Mercedes-Benz officially quotes a 0-60 mph acceleration time of just 3.4 seconds for the GLC 63 S. This is marginally quicker than the 3.5 seconds previously recorded for the V8-powered GLC 63 S model in Edmunds testing. Although the horsepower figures have significantly increased in the new model compared to the previous 503 horsepower V8, the performance gain is slight. This minor difference is likely attributable to the increased weight of the 2025 model, a consequence of incorporating additional equipment such as the 6.1-kWh battery pack. Mercedes-Benz has yet to release the final specifications, but it is anticipated that the 2025 GLC 63 S will be heavier than its predecessor due to these additions.
Despite the expected weight increase, the GLC 63 S never feels cumbersome or overweight on the road. It possesses more than sufficient power for everyday driving scenarios, and unlocking its full performance potential truly requires expansive, open roads. The transmission operates with remarkable smoothness in typical driving conditions, yet it delivers incredibly rapid upshifts when engaged in one of the sport driving modes. The steering wheel paddles offer enhanced driver engagement and control, but the automatic transmission tuning is intelligent enough to intuitively select the optimal gear for most driving situations.
The handling of the GLC 63 S is equally impressive, with AMG engineers effectively mitigating the perceived weight through sophisticated chassis engineering. Standard adaptive dampers continuously adjust the suspension’s responsiveness based on road conditions and the selected drive mode. In comparison, competitors like the BMW X3 M Competition can exhibit a ride stiffness that might become fatiguing on less-than-perfect road surfaces. However, the GLC 63 S offers a more compliant ride, although it does become noticeably firmer in the Sport+ or Race modes. The optional active roll stabilization system further enhances handling and comfort by utilizing multi-piece anti-sway bars, which can decouple from left to right as needed, improving ride quality without compromising cornering performance.
Body roll in corners is well-controlled, although the GLC 63 S does exhibit slightly more lean than a sport sedan like the Mercedes-Benz C 63 S. Similarly, brake dive is minimal but more pronounced than in a dedicated sports sedan. The braking system is a mixed bag. While possessing ample stopping power, the brake pedal feels somewhat stiff and requires more effort to modulate than anticipated, particularly when approaching traffic lights or stop signs. Drivers will likely adapt to the pedal feel quickly, but a more immediate initial bite would be preferable. Another minor drawback is the available one-pedal driving function. Offering four settings, including a fully off position, none of the one-pedal modes provide particularly aggressive deceleration or bring the vehicle to a complete stop. It is arguably more intuitive and effective to drive the GLC 63 S without engaging the one-pedal driving feature. While not equipped on the test vehicle and not immediately available at launch, carbon-ceramic brakes are expected to be offered as an option in the future.
Standard rear-axle steering enhances both low-speed maneuverability and high-speed stability. At speeds below 62 mph (100 kph), the rear wheels steer in the opposite direction to the front wheels by a few degrees, effectively reducing the turning radius, simplifying parking, and improving cornering agility. Above this speed threshold, the rear wheels steer in the same direction as the front wheels, enhancing stability during high-speed driving. Early iterations of rear-axle steering systems sometimes felt artificial or unpredictable, but AMG has refined the system in the GLC 63 S to operate seamlessly and intuitively. The GLC 63 S exhibits a slightly quicker turn-in response than expected for its size, but it feels natural and contributes to the vehicle’s overall responsiveness. The steering system itself is well-weighted and precise. While not providing an abundance of tactile feedback, the steering effort is perfectly judged, and the steering ratio is quick without feeling overly darty or nervous.
In conclusion, the Mercedes-Benz GLC 63 S proves to be genuinely enjoyable to drive on winding roads. However, truly exploiting its performance capabilities necessitates ample space and sweeping curves. While possessing immense capability for diverse driving situations, the new engine’s exhaust note, although powerful, lacks the distinctive auditory character and emotional resonance of the previous V8 engine’s soundtrack. Despite this minor subjective point, the 2025 Mercedes-Benz GLC 63 S stands as a highly accomplished performance SUV, blending sophisticated technology with engaging driving dynamics.
