20 MPG combined. That’s the EPA estimate for the 2020 Mercedes-Benz AMG S63 4matic Plus, and it’s almost irrelevant. The person buying this hand-built, twin-turbocharged V8 sledgehammer isn’t cross-shopping with a Prius. They’re buying a hyper-luxurious sedan that happens to have four doors and enough space to comfortably transport their preferred entourage, and they understand that kind of performance demands a price at the pump.

City and highway performance

The EPA estimates 17 MPG in the city and 26 MPG on the highway for the S63’s potent 4.0L V8. Let’s be honest, the “city” figure is a best-case scenario. The temptation to exploit the readily available 603 horsepower and 664 lb-ft of torque at every green light is simply too overwhelming for most owners. Expect to see numbers dip considerably below 17 if you frequently indulge in the S63’s raw power. On the open road, achieving 26 MPG is a far more realistic prospect, particularly if using cruise control and resisting the urge to pass every car in sight. While not a fuel sipper, the relatively high highway number illustrates the efforts Mercedes-AMG has made to optimize efficiency, including cylinder deactivation and a smooth-shifting 9-speed automatic transmission.

Annual fuel cost

The EPA estimates an annual fuel cost of $2,900 for the 2020 Mercedes-Benz AMG S63 4matic Plus. This figure is based on driving 15,000 miles per year and using the national average fuel price for premium gasoline, which the S63 requires. Keep in mind that this is just an estimate. Your actual fuel costs will vary depending on your driving habits, the type of roads you typically drive on, and fluctuations in gasoline prices. Heavier-footed drivers, especially those frequently engaging in spirited driving, can expect to exceed the $2,900 estimation considerably. For those browsing all Mercedes Benz fuel economy data, this number offers a clear point of comparison.

Real-world expectations

While the EPA figures provide a benchmark, real-world fuel economy for the AMG S63 is highly dependent on driving style. Someone primarily using the car for long highway cruises might see numbers closer to the EPA estimates, especially if they engage the “Comfort” driving mode. However, anyone regularly exploiting the car’s prodigious power, particularly in urban environments, should expect to see significantly lower MPG figures. The S63 isn’t designed for economy; it’s built for performance, and its official MPG figures can be considered aspirational under such conditions.

How it compares

Compared to other high-performance luxury sedans, the S63’s fuel economy is about what you’d expect. The BMW M760i xDrive, with its V12 engine, gets an EPA-estimated 16 MPG combined. The Porsche Panamera Turbo, another direct competitor, achieves a slightly better 19 MPG combined in its standard configuration, though opting for the more powerful Turbo S E-Hybrid model actually results in a modestly improved 21 MPG. Even within the AMG family, as you can see by browsing AMG MPG across all years, the S63 is thirstier than its smaller siblings like the AMG C63, which achieves 20 MPG combined. The relatively similar MPG figures among these high-performance competitors underscore the fact that extreme performance and efficiency rarely coexist in this segment.

Tips to maximize efficiency

While the AMG S63 is hardly a fuel-efficient vehicle, there are still a few things owners can do to improve gas mileage. Use the “Comfort” driving mode whenever possible, as this mode softens throttle response, optimizes shift points, and engages cylinder deactivation more frequently, all contributing to improved fuel economy.

Avoid aggressive acceleration and hard braking. The S63’s immense power is readily available, but exploiting it constantly will dramatically reduce fuel efficiency. Smooth, gradual acceleration is key to conserving fuel.

Ensure that your tires are properly inflated. Underinflated tires increase rolling resistance, which negatively impacts fuel economy. Check your tire pressure regularly and inflate them to the recommended pressure, typically found on a sticker inside the driver’s side door. Schedule regular maintenance too.

Minimize idling. Modern engines consume fuel even when stationary. If you anticipate being stopped for an extended period, turn off the engine. Similarly, avoid using remote start excessively, as this also wastes fuel.