21 MPG combined is likely not the primary reason someone buys a 2020 Mercedes-Benz AMG C43 4matic Convertible. Buyers are likely seeking a driving experience defined by sharp handling, rapid acceleration, and open-air enjoyment. Fuel efficiency is a secondary consideration, perhaps somewhere below seat ventilation and above cupholder size on the priority list. This car is about emotion, and those emotions are fueled by premium gasoline.

City and highway performance

The EPA estimates the C43 convertible will achieve 18 MPG in the city and 25 MPG on the highway. The difference reflects the car’s character. In urban environments, the C43’s turbocharged engine spends more time working harder, negating any potential fuel savings from its nine-speed automatic transmission. On the open road, however, with the engine running at a more consistent speed, 25 MPG becomes achievable. This isn’t a hybrid designed for maximizing fuel economy; it’s an AMG, built for performance. The relatively low highway number shows this.

Annual fuel cost

The EPA estimates drivers of the 2020 Mercedes-Benz AMG C43 4matic Convertible will spend approximately $2,750 per year on fuel. This calculation is based on driving 15,000 miles annually, using the national average fuel price for premium gasoline. This figure provides a standardized benchmark for comparing fuel costs across different vehicles. However, individual fuel expenses will vary depending on driving habits, local fuel prices, and how aggressively the car is driven. The C43’s turbocharger encourages frequent use of the accelerator, which won’t help keep fuel costs down.

Real-world expectations

Expect to see numbers slightly below the EPA estimates in daily driving, especially if you frequently exploit the engine’s potential. Spirited acceleration and frequent use of “Sport+” mode will quickly reduce those official fuel economy figures. Some owners report combined MPG figures in the high teens, especially in areas with heavy traffic or hilly terrain. Conversely, a careful driver sticking to highway cruising at reasonable speeds might be able to match or even slightly exceed the 25 MPG highway rating. But restraint is not a common characteristic among C43 owners.

How it compares

The C43 resides in a similar fuel consumption bracket as its competitors. The BMW M440i xDrive Convertible, another performance-oriented convertible, achieves a combined 25 MPG. The Audi S5 Cabriolet, with its turbocharged V6, also posts a combined figure of 24 MPG. These vehicles, like the C43, prioritize performance over outright fuel economy. A less powerful convertible, such as the Lexus LC 500 Convertible at 18 MPG combined, offers better efficiency. However, a potential C43 buyer is unlikely to cross-shop a Lexus. To find all Mercedes Benz fuel economy data, browse our database.

Tips to maximize efficiency

Anticipate traffic flow and maintain a steady speed when possible. Avoid abrupt acceleration and braking, as these actions consume significantly more fuel, especially when the turbocharger engages. The C43 encourages aggressive driving, but a smoother driving style will have a big impact.

Ensure your tires are properly inflated. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Check your tire pressures regularly and inflate them to the recommended levels found on the doorjamb sticker.

Use the “Comfort” driving mode for everyday commuting. While “Sport” and “Sport+” modes deliver more responsive performance, they also hold gears longer and increase fuel consumption. Comfort mode optimizes throttle response and shift points for efficiency without sacrificing too much driving enjoyment. Consider searching AMG MPG across all years to compare models.

Lighten the load. Remove any unnecessary items from your car, as excess weight reduces fuel economy. This is especially true for items stored in the trunk, as they add weight to the rear of the vehicle, impacting weight distribution. The only thing in the trunk should be luggage for a weekend getaway!

Consider the fuel quality and ethanol content. The C43 requires premium gasoline, but be mindful of the ethanol content, as higher concentrations can negatively impact fuel economy. Opt for gasoline with lower ethanol levels when possible, or use a fuel additive designed to offset the effects of ethanol.