20 MPG combined. That’s the figure associated with the 2018 Mercedes-Benz AMG C63 S, and it’s a number that needs immediate context. This isn’t a car someone buys if saving fuel is their primary concern. It’s a snarling, visceral performance machine with a handcrafted 4.0-liter V8, an engine designed to elicit grins and audible gasps, not hypermiling techniques. If you’re cross-shopping this with a Prius, you’ve wandered far off course. The C63 S buyer wants devastating acceleration, a thunderous exhaust note, and the ability to carve corners with surgical precision. Fuel economy, while perhaps a consideration, is a distant afterthought.

City and highway performance

The EPA estimates the C63 S at 18 MPG in the city and 24 MPG on the highway. The city figure reflects the stop-and-go nature of urban driving, where the engine spends more time idling or accelerating from a standstill. The car’s aggressive throttle response, while exhilarating, does little to help in heavy traffic. The highway figure, while better, still acknowledges the reality of a high-performance engine working to overcome aerodynamic drag at higher speeds. Even with a relatively modern 7-speed automatic transmission doing its best to optimize efficiency, the V8 is always ready to unleash its power, impacting fuel consumption even during steady-state cruising.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2018 Mercedes-Benz AMG C63 S at $2,900. This figure is based on driving 15,000 miles per year and using national average fuel prices for premium gasoline, which this car requires. It’s a sobering reminder that owning a high-performance vehicle comes with running costs beyond the initial purchase price. Expect to visit the gas station frequently, and brace yourself for higher fuel bills than the average car owner.

Real-world expectations

While the EPA provides a standardized benchmark, real-world fuel economy can vary significantly based on driving style, traffic conditions, and even ambient temperature. Drivers with spirited acceleration and frequent use of the car’s performance modes may find themselves dipping below the EPA’s 20 MPG combined estimate. Conversely, those who predominantly drive on the highway and adopt a more conservative driving style might see slightly better numbers. However, consistently achieving the EPA highway estimate will require a mindful approach to throttle inputs and a deliberate effort to resist the urge to exploit the engine’s power.

How it compares

Compared to its rivals, the C63 S’s fuel economy is generally in line with expectations for its performance class. The BMW M3 CS, for example, also offers a combined EPA rating of 20 MPG with 17 MPG city and 23 MPG highway. The now discontinued Cadillac ATS-V, with its twin-turbo V6, offered a slightly better 18 MPG city and 26 MPG highway. These marginal MPG variations ultimately become less important to the buyer than the driving characteristics and brand prestige. Someone considering the C63 S likely isn’t prioritizing fuel economy over the intoxicating sound and feel of a handcrafted AMG engine, nor are they likely weighing all Mercedes Benz fuel economy data as part of their search. They may, however, be weighing AMG MPG across all years.

Tips to maximize efficiency

While the C63 S isn’t designed for optimal fuel efficiency, there are still steps owners can take to minimize consumption. Gentle acceleration and anticipating traffic flow can significantly reduce fuel consumption. Avoid aggressive starts and sudden braking, as these actions demand more fuel than gradual maneuvering.

Use the car’s driving modes strategically. The “Comfort” mode, while less engaging than “Sport” or “Sport+,” will soften throttle response and prioritize fuel efficiency over outright performance. Selecting this mode during highway cruising or stop-and-go traffic can make a noticeable difference.

Ensure proper tire inflation. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Regularly check and maintain the recommended tire pressure to optimize fuel efficiency and prolong tire life.

Reduce unnecessary weight. Carrying extra cargo increases the overall weight of the vehicle, negatively impacting fuel economy. Remove any unnecessary items from the trunk and passenger compartment to minimize fuel consumption.

Consider the use of cruise control on the highway. Maintaining a consistent speed using cruise control helps to avoid fluctuations in throttle position, leading to more efficient fuel consumption during long highway drives.