20 MPG combined. No one selects a 2019 Mercedes-Benz AMG C63 S Convertible for its practicality or fuel efficiency. This car exists for those who prioritize the thrill of a handcrafted, twin-turbocharged V8 with open-air motoring. It’s thirsty, but that thirst is part of the experience, a byproduct of the performance.

City and highway performance

The C63 S Convertible delivers 17 MPG in the city and 24 MPG on the highway. These figures reflect the engine’s output more than any attempts at hypermiling. The city number is predictable given urban driving, which constantly demands power from the engine. On the highway, resist the urge to explore the car’s passing power too frequently to see that 24 MPG. Drive aggressively, and that figure drops. The 9-speed automatic transmission optimizes efficiency at cruising speeds, but the car’s aggressive tuning means even light throttle applications can trigger a downshift and a fuel economy dip.

Annual fuel cost

According to the EPA, the annual fuel cost for the 2019 Mercedes-Benz AMG C63 S Convertible is $2,900. This calculation assumes 15,000 miles of driving per year, based on the national average fuel price for premium gasoline, which this engine requires. Drivers covering more miles, or those with a heavier foot, should anticipate spending more. The $2,900 figure is a benchmark, but owners should be prepared for a substantial annual fuel bill.

Real-world expectations

While the EPA provides an estimate, real-world mileage can vary based on driving style and conditions. The C63 S Convertible encourages spirited driving, and frequent acceleration lowers fuel economy. Expect numbers closer to the city figure if your commute involves heavy traffic or aggressive driving. Longer highway trips at a steady speed should allow you to approach the EPA’s 24 MPG estimate. Consider your driving environment when estimating your personal fuel costs.

How it compares

Competitors in the high-performance convertible segment face similar fuel economy challenges. The BMW M4 Convertible, another key rival, manages around 17 MPG city and 25 MPG highway with its turbocharged inline-six. The Audi RS 5 Cabriolet, with its V6 engine, posts similar figures. These slight differences are unlikely to sway a buyer in this segment; performance and driving experience receive more emphasis. Open-top motoring with this level of power comes at a cost. You can see all Mercedes Benz fuel economy data to see how the C63 compares to milder models. Or check the AMG MPG across all years to view other AMG variants.

Tips to maximize efficiency

Although the C63 S Convertible isn’t designed for optimal fuel economy, a few techniques can help you minimize fuel consumption. Use the car’s “Comfort” driving mode in everyday situations; this will soften throttle response and encourage earlier upshifts. This can improve fuel efficiency in stop-and-go traffic compared to the “Sport” or “Sport+” modes.

Avoid unnecessary idling. Modern engine technology makes prolonged idling wasteful. If you’re stopped for more than a minute or two, turn off the engine, particularly in urban environments with frequent traffic signals.

Maintain proper tire inflation. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Check your tire pressures regularly and ensure they match the manufacturer’s recommendations, which can be found on the driver’s side doorjamb or in the owner’s manual.

Lighten the load. Extra weight in the vehicle reduces fuel economy. Remove unnecessary items from the trunk and passenger compartment to minimize the burden on the engine. While this won’t dramatically improve your MPG, every bit helps.