18 MPG combined in the 2025 Mercedes-Benz AMG SL63 S E Performance 4.0L 8-cyl isn’t a statistic that deters its target demographic. It’s a footnote, a minor detail in a symphony of power, luxury, and advanced engineering. This isn’t a vehicle purchased for its low fuel consumption, but rather despite its thirst. It’s a roadster that delivers visceral thrills, blistering acceleration, and an intoxicating exhaust note that demands to be heard, all while swaddling its occupants in an opulent, tech-laden cabin. This car is an unapologetic statement of performance and prestige, a machine designed to stir the soul with every blip of the throttle, and the fuel economy figures simply reflect the raw intensity under the hood.

City and highway performance

The 2025 AMG SL63 S E Performance achieves 16 MPG in the city and 22 MPG on the highway. These numbers are a direct consequence of the extraordinary powertrain housed within this sleek chassis. The 4.0L twin-turbocharged V8, augmented by an electric motor, delivers colossal horsepower and torque figures, translating into breathtaking acceleration and relentless power delivery. City driving, with its frequent stops and starts, naturally sees a higher consumption rate as the engine cycles through its formidable power band, though the hybrid assist provides moments of electric-only propulsion that can, on occasion, offer surprising bursts of quiet efficiency. On the open highway, where the 9-speed automatic transmission allows the engine to settle into a relaxed cruise, the SL63 S E Performance can stretch its fuel further, hinting at the underlying advanced engineering. But make no mistake, this is a vehicle that encourages enthusiastic driving, and any lead-footed adventurer will see these numbers dip accordingly.

Annual fuel cost

The EPA estimates an annual fuel cost of $3,200 for the 2025 Mercedes-Benz AMG SL63 S E Performance. This figure is calculated based on an assumption of 15,000 miles driven per year, split between city and highway driving, using national average fuel prices for premium gasoline. For the individual considering a vehicle like the AMG SL63 S E Performance, this substantial annual fuel expenditure is rarely a primary concern. The buyer of this roadster is investing in a highly refined, immensely powerful, and technologically advanced machine, where the cost of premium fuel is simply part of the ownership experience. This $3,200 represents the price of admission to a world of uncompromising performance and luxury, a sum that aligns with the overall financial commitment of purchasing and maintaining such a potent and exclusive automobile.

Real-world expectations

In real-world driving, owners of the 2025 AMG SL63 S E Performance should anticipate fuel economy figures that closely mirror, or even fall below, the EPA’s estimates, particularly if they routinely exploit the vehicle’s immense performance capabilities. The relationship between the 4.0L twin-turbo V8 and the electric motor is designed for maximum power and instant torque, not for low fuel consumption. Aggressive acceleration, frequent stints in Sport+ mode, and spirited canyon carving will undoubtedly result in single-digit MPG readings. However, even during more sedate cruising, the sheer displacement and power of the engine mean it requires a hearty appetite for premium fuel. The hybrid system does offer some mitigation, particularly in stop-and-go traffic or during low-speed maneuvers, allowing for brief periods of electric-only travel. Yet, the core purpose of this E Performance designation is to enhance performance, not primarily to reduce fuel consumption. Drivers should manage their expectations accordingly, viewing the fuel gauge as a rapidly descending needle during moments of pure driving exhilaration. For a deeper dive into all Mercedes Benz fuel economy data, our database offers extensive information.

How it compares

Direct comparisons for the 2025 AMG SL63 S E Performance are few, given its unique blend of plug-in hybrid performance, luxury, and top-down exhilaration. We can look at some competitors that similarly prioritize power and prestige. A key rival might be the Porsche 911 Turbo S Cabriolet, which, purely gasoline-powered, achieves around 17 MPG combined (15 city / 20 highway). The Porsche sacrifices the hybrid boost but delivers a similarly thrilling, albeit different, driving experience. Another contender could be the Bentley Continental GT Convertible, a more opulent and less overtly sporting machine, which typically manages around 17 MPG combined (14 city / 22 highway) from its powerful W12 engine. Looking towards more hybrid-centric large performance convertibles is tricky, as the SL63 S E Performance is carving out its own niche. However, a high-performance luxury sedan that uses similar technology, such as the Porsche Panamera Turbo S E-Hybrid, achieves a significantly higher 20 MPGe combined (though this includes electric-only range, a different metric than the SL’s performance-oriented hybrid system). The crucial distinction is that the SL’s hybrid system is primarily a performance enhancer, boosting output and providing instant torque rather than extending all-electric range over long distances. The SL’s 18 MPG combined is right in line with, if not slightly better than, its ultra-high-performance, non-hybrid luxury convertible counterparts, showcasing the innovative way Mercedes-AMG has integrated electrification not for economy, but for outright speed. Explore AMG MPG across all years to see the evolution of their performance metrics.

Tips to maximize efficiency

While the 2025 AMG SL63 S E Performance is not about eco-driving, small adjustments can make a difference. Engaging the “Comfort” driving mode softens throttle response and optimizes gear changes for smoother, less aggressive power delivery, which can marginally improve fuel consumption in daily traffic.

Using the regenerative braking system by anticipating stops and coasting whenever possible allows the electric motor to recuperate energy, subtly contributing to overall efficiency and lessening the load on the gasoline engine.

Maintaining proper tire pressure is a simple yet effective method to reduce rolling resistance. Correctly inflated tires ensure the vehicle operates at its intended efficiency, preventing unnecessary energy loss.

Avoid unnecessary weight in the trunk. While a marginal improvement, every pound adds to the effort required to move the vehicle. Removing forgotten items can contribute to a slight decrease in fuel usage.

Smooth and consistent acceleration, rather than abrupt bursts of speed, will always be more fuel-efficient. While tempting in a car of this caliber, a gentler approach to the throttle will keep more fuel in the tank for longer.