20 MPG combined. That number isn’t going to impress anyone looking for economy. The raw thrill of a hand-built, twin-turbocharged V8, the wind in your hair, and the sound of controlled explosions from the AMG quad exhaust pipes are the priority if you’re buying a 2020 Mercedes-Benz AMG C63 S Convertible. Fuel costs are likely an afterthought. This vehicle delivers an unapologetic driving experience, and that comes at a price in dollars, but also in gallons per mile.

City and highway performance

Around town, the C63 S convertible manages just 17 MPG. Stop-and-go traffic and the temptation to unleash the engine’s power will quickly deplete the fuel tank. Of course, you get instant acceleration and an exhaust note that turns heads. Out on the open road, the C63 S achieves a slightly more palatable 24 MPG. With the top down and the cruise control set, you might even be able to stretch that figure a bit further. The 4.0L V8 isn’t exactly quiet at highway speeds, as power is always available with a tap of the accelerator.

Annual fuel cost

The EPA estimates an annual fuel cost of $2,900 for the 2020 Mercedes-Benz AMG C63 S Convertible. This figure is based on driving 15,000 miles per year, with 45% of those miles driven in the city and 55% on the highway. The calculation also assumes the national average fuel price. Actual fuel costs will vary depending on individual driving habits, local gasoline prices, and how often the driver gives in to the C63’s performance.

Real-world expectations

The EPA estimates provide a baseline, but expect those numbers to change in real-world driving. Someone using the C63 S convertible as a daily commuter in heavy traffic will likely see fuel economy dip below the city estimate. Someone who primarily uses the car for weekend cruises on open highways might get closer to, or even exceed, the highway figure. Driving style also plays a role. Aggressive acceleration and frequent use of Sport+ or Race mode will significantly impact fuel consumption. If a driver resists accelerating too fast, they will be rewarded with slightly better fuel economy.

How it compares

Compared to other high-performance convertibles, the C63 S’s fuel economy falls in the middle. A BMW M4 Convertible, with its inline-six, achieves a slightly better 22 MPG combined. The Audi RS5 Cabriolet comes in at 21 MPG combined. A V8-powered Chevrolet Corvette convertible fares similarly. The C63s’ competition offers a similar balance between performance and relative efficiency. Fuel economy is unlikely to be the deciding factor for buyers of these vehicles. Performance, styling, brand, and overall driving experience will weigh more heavily. If you’re curious to explore the broader picture, you can examine all Mercedes Benz fuel economy data.

Tips to maximize efficiency

Resist constantly using launch control and full-throttle acceleration. The twin-turbo V8 is powerful, but restraint will save gas. Shift into “Comfort” mode when possible. It optimizes the transmission and engine settings for fuel efficiency. Those other modes are ‘fun’ modes that cost you MPG if you abuse them.

Ensure that your tires are properly inflated. Under-inflated tires increase rolling resistance, which reduces fuel economy. Check your tire pressures regularly, especially before long drives.

Avoid unnecessary idling. If you’re stopped for more than a minute, turn off the engine. Modern vehicles are designed for easy restarts, and the fuel saved by avoiding idling can add up.

Plan your routes to avoid traffic. Stop-and-go traffic significantly reduces fuel economy. Consider navigation apps to find efficient routes, even if they’re not the most direct.

Keep up with regular maintenance. A properly maintained engine runs more efficiently. Follow the manufacturer’s recommended maintenance schedule, including oil changes, air filter replacements, and spark plug replacements. While you’re researching, check out AMG MPG across all years to see how this performance division has evolved.