16 MPG combined for the 2026 Mercedes-Benz AMG SL63 4MATIC+ 4.0L V8 is a declaration. This isn’t a vehicle sculpted for efficiency contests or grocery runs where every drop matters. This is a 577-horsepower, twin-turbocharged, luxuriously appointed missile designed to obliterate autobahn stretches and devour canyon roads with the visceral roar only a hand-built AMG engine can provide. Its purpose is unadulterated performance, grand touring, and the kind of top-down experience that redefines luxury roadstering. The SL63 owner understands this equation instinctively. They’re buying into a lifestyle, a statement of capability and prestige, where the exhilarating rush of the accelerator and the symphony from the quad exhaust tips take precedence over the digital readout at the fuel pump. For this echelon of buyer, fuel consumption is a calculated, and often embraced, cost of admission to an exclusive club of driving dynamics.

City and highway performance

The EPA’s breakdown of 14 MPG city and 21 MPG highway paints a clearer picture of the SL63’s operational realities. Around town, the strong 4.0L V8, even with its cylinder deactivation technology, is constantly battling the nearly two-ton curb weight and the inherent inefficiencies of stop-and-go driving. Pulling away from lights, navigating congested streets, and the general on-and-off throttle nature of urban driving naturally keep the turbos spooling and the fuel flowing. Owners fully expect this. The joy of a prompt, effortless surge of power from any RPM is a core part of the AMG experience. Out on the open road, the 21 MPG highway figure becomes more attainable. Here, the engine settles into its long-legged stride. The 9-speed automatic transmission allows the V8 to cruise at lower, more economical RPMs, and the aerodynamic slipperiness of the SL’s silhouette plays its part. Long distance cruises, whether a cross-state jaunt or a leisurely drive down the coast, are where the SL63 can stretch its legs and deliver its most favorable efficiency, all while the driver and passenger enjoy superlative comfort and the optional Burmester sound system.

Annual fuel cost

The EPA estimates an annual fuel cost of $3,600 for the 2026 Mercedes-Benz AMG SL63 4MATIC+ 4.0L V8. This figure is based on a standard assumption of driving 15,000 miles per year, with an approximate split of 45% highway and 55% city driving, using national average fuel prices for premium gasoline. It’s a critical data point for any potential owner to consider, though for the typical SL63 buyer, it’s rarely a deal-breaker. This isn’t a cost-conscious decision, it’s an integrated expense in owning a high-performance, ultra-luxury convertible. This specific annual cost is simply a reality check, a quantification of the fuel needed to power the relentless acceleration and strong performance inherent in the AMG badge. Understanding this $3,600 figure means acknowledging the ongoing operational expense associated with exhilarating performance, not just the initial purchase price.

Real-world expectations

In the real world, owners of the AMG SL63 will find their fuel economy figures vary considerably depending on their driving style and environment. If you frequently exploit the immense power on tap, engaging the full throttle and hearing the characteristic AMG snarl, expect to see figures closer to, or even below, the 14 MPG city estimate. These vehicles are designed to be driven spiritedly, and most owners will do exactly that, reveling in the immediacy of its power delivery. Conversely, a disciplined driver embarking on a long highway journey with cruise control engaged and a light foot will likely exceed the 21 MPG highway rating, perhaps even reaching the mid-20s. The 4MATIC+ all-wheel drive, while adding traction and stability, also contributes slightly to driveline losses, but the benefits in grip and confidence, especially in dynamic driving, far outweigh any minuscule fuel economy penalty. The key takeaway is: buy an SL63 for its soul-stirring performance and peerless luxury, and the fuel economy will be a secondary, if acknowledged, consideration. You can find more AMG MPG across all years here.

How it compares

Comparing the SL63’s 16 MPG combined figure reveals its position square within the high-performance luxury convertible segment, a segment that prioritizes exhilaration over economy. A direct competitor like the Porsche 911 Turbo S Cabriolet, with even more power, delivers roughly 17 MPG combined, indicating a marginal efficiency edge despite its performance. A slightly less powerful, but still potent, Aston Martin Vantage Roadster with its 4.0L V8 manages around 18 MPG combined. Stepping into the realm of the BMW M8 Competition Convertible, you’ll find similar figures, hovering around 17 MPG combined. The buyer choosing the SL63 isn’t cross-shopping with, say, a Lexus LC 500 Convertible (20 MPG combined) purely on efficiency. Instead, they are evaluating the brand prestige, the unique AMG tuning, the advanced technology, and the specific character of its V8 engine. The SL63 boasts a distinct blend of aggressive capability and comfort that sets it apart. The slight variations in MPG among these top-tier vehicles are largely irrelevant. The decision comes down to brand allegiance, driving dynamics preference, and aesthetic appeal. Explore all Mercedes-Benz fuel economy data for a broader perspective.

Tips to maximize efficiency

For those rare moments when fuel economy takes a higher priority in the SL63, adopting specific driving habits can yield noticeable improvements. Engaging the Comfort or Eco driving modes will soften throttle response, encourage earlier upshifts from the 9-speed transmission, and make the cylinder deactivation system more active, allowing the engine to run on fewer cylinders more often when cruising.

Maintaining consistent highway speeds without aggressive acceleration or braking is important. Using cruise control on open roads prevents unnecessary speed fluctuations, keeping the engine in its most efficient operating range and reducing the frequent turbocharger spooling that consumes more fuel.

Staying up-to-date with factory-recommended maintenance, such as timely oil changes, air filter replacements, and spark plug checks, ensures the engine operates at peak efficiency. A well-maintained engine is an efficient engine, minimizing fuel waste caused by dirty components or worn parts.

Careful tire management is often overlooked. Ensuring the high-performance tires are correctly inflated according to Mercedes-Benz specifications reduces rolling resistance, directly translating to better fuel economy. Underinflated tires make the engine work harder, consuming more fuel.

Finally, consider shedding unnecessary weight. While impractical for everyday use, removing heavy items from the trunk that aren’t needed for a journey can marginally reduce the vehicle’s load, thereby slightly improving efficiency, particularly in city driving where acceleration is frequent.