18 MPG combined is what you get with the 2017 Mercedes-Benz AMG CLS63 S 4matic. That figure acknowledges you’re getting a hand-built, bi-turbocharged 5.5L V8 under the hood, an engine that favors ferocious acceleration and a guttural soundtrack over fuel sipping. This isn’t a grocery-getter; it’s a statement. The CLS63 S buyer isn’t prioritizing Prius-like efficiency. They’re looking for a distinctive four-door coupe with performance credentials to rival dedicated sports cars, and they’re prepared to pay at the pump to get it.

City and highway performance

The EPA estimates that the 2017 AMG CLS63 S gets 16 MPG in the city and 22 MPG on the highway. While these numbers might seem low in today’s world of hybrid and electric vehicles, remember this is a powerful, all-wheel-drive performance machine. The city MPG reflects stop-and-go traffic, where the engine’s torque and relatively heavy curb weight require more fuel to get moving. The highway figure demonstrates the engine’s ability to cruise efficiently at higher speeds, but even aggressive driving will quickly diminish these numbers.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for the 2017 Mercedes-Benz AMG CLS63 S 4matic is $3,200. This figure is based on driving 15,000 miles per year, using the EPA’s combined fuel economy rating of 18 MPG, and factoring in national average fuel prices. Premium fuel is required for optimal performance in the CLS63 S, which is factored into the EPA’s estimate. So, if you typically drive more than 15,000 miles annually, or if fuel prices in your region are higher than the national average, expect your actual fuel expenses to exceed this estimate.

Real-world expectations

While the EPA provides a standardized estimate, real-world fuel economy for the 2017 AMG CLS63 S will vary depending on driving style, traffic conditions, and maintenance habits. Someone who frequently unleashes the engine’s immense power will likely see numbers significantly lower than 18 MPG combined. Conversely, someone who drives conservatively and spends more time on the highway might get closer to the EPA’s estimates. Tire pressure, vehicle load, and even weather conditions can also impact fuel consumption. Remember to consult all Mercedes Benz fuel economy data for even more model-specific stats.

How it compares

Compared to its competitors, the 2017 AMG CLS63 S has similar fuel economy. The 2017 BMW M6 Gran Coupe, with its 4.4L twin-turbo V8, achieves an EPA estimated 17 MPG combined. The Porsche Panamera Turbo from the same year manages around 18 MPG combined, aligning closely with the CLS63 S. Even the Audi RS7, another potent contender, averages about 18 MPG combined. These numbers show that performance luxury vehicles with powerful engines inherently sacrifice fuel efficiency. The slight variances often come down to differences in engine displacement, transmission tuning, and specific drivetrain configurations. For a broader view, explore AMG MPG across all years.

Tips to maximize efficiency

While squeezing every last mile out of a tank might not be the primary concern of a CLS63 S owner, some strategies can help improve fuel economy without sacrificing enjoyment behind the wheel. Avoid aggressive acceleration and braking. The AMG’s immense torque can easily lead to rapid bursts of speed followed by hard braking, both of which consume excessive fuel.

Maintain proper tire inflation. Underinflated tires increase rolling resistance, forcing the engine to work harder and burn more fuel. Check your tire pressures regularly and inflate them to the recommended levels.

Use the car’s driving modes intelligently. If you’re not planning on engaging in spirited driving, selecting a more conservative driving mode can optimize shift points and throttle response for better fuel economy. While the “S+” mode is thrilling, it’s best saved for when you want to exploit the car’s performance capabilities.

Minimize idling. Letting the engine idle for extended periods, such as while waiting in a parking lot or drive-thru, wastes fuel. If you anticipate a wait of more than a minute or two, it’s better to turn off the engine and restart it when you’re ready to go.

Consider lighter wheels and tires when it’s time for replacements. While the factory wheels suit the car aesthetically, aftermarket wheels, especially forged units, are often lighter and better suited to minimizing rotational mass, leading to slight improvement in fuel economy. The same goes for low-rolling-resistance tires in the correct size.