The 18 MPG combined shouldn’t shock anyone considering the 2019 Mercedes-Benz AMG GLC63 S 4matic Coupe. This isn’t a vehicle purchased for economy; it’s bought for thunderous V8 performance, assertive styling, and the prestige of the AMG badge. Fuel efficiency is less important than the visceral experience of 503 horsepower propelling a coupe-ified SUV with a snarling exhaust note. Buyers in this segment are prioritizing adrenaline over frugality, and the GLC63 S delivers that strongly.

City and highway performance

The EPA estimates the GLC63 S Coupe at 16 MPG in the city and 22 MPG on the highway. The city figure reflects the reality of stop-and-go traffic, where the powerful engine constantly cycles between bursts of acceleration and idling, situations that heavily penalize fuel consumption. The highway number improves somewhat, but even then, the aerodynamic compromises inherent in the coupe SUV design, plus the engine’s inherent thirst, prevent it from achieving truly impressive numbers. Remember that using the GLC63 S’s prodigious power to make quick passes on the highway will lead to lower-than-stated fuel economy.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2019 Mercedes-Benz AMG GLC63 S Coupe at exactly $3,200. This figure is calculated assuming 15,000 miles of driving per year and using the national average fuel price for premium gasoline (as this AMG model requires). It’s a substantial cost, reflecting the vehicle’s lower MPG and the demand for pricier premium fuel. It’s useful to remember that real-world gas prices fluctuate considerably, depending on where you live, so your actual expenditure could vary from this projection.

Real-world expectations

Owners of the GLC63 S Coupe are unlikely to consistently achieve the EPA’s estimates while driving. The temptation to exploit the available performance is simply too strong. Those who frequently engage in spirited driving, with hard acceleration and frequent use of the sport modes, should expect to see significantly lower figures, potentially dipping into the low teens around town. Conversely, drivers who primarily use the vehicle for longer highway trips, and exercise restraint with the accelerator, might see numbers closer to the EPA’s 22 MPG highway rating. But nobody buys this car to drive it in “eco” mode all the time. The rumble of the AMG V8 is too enticing.

How it compares

The fuel economy of the AMG GLC63 S Coupe isn’t exactly class-leading. The Porsche Macan Turbo, with its 2.9L twin-turbo V6, manages a slightly better 19 MPG combined. Even the BMW X3 M Competition, with its inline-6 engine, often achieves around 16 MPG city/21 MPG highway. While these differences may seem small on paper, they can add up over time. The key, however, is to understand the philosophy behind each vehicle. The Porsche emphasizes precision and handling, while the BMW splits the difference between performance and practicality. The AMG offers brute force and a sound experience that few other vehicles can match. If you’re comparing fuel economy between the GLC63 S and the standard GLC models, you’ll find a significant difference as all Mercedes Benz fuel economy data will show. The AMG MPG across all years is generally lower than standard Mercedes-Benz models.

Tips to maximize efficiency

Resist the urge to constantly use the GLC63 S’s full power. This is easier said than done, but avoiding frequent hard acceleration will noticeably improve fuel economy.

Ensure that your tires are properly inflated. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel.

Use the car’s “Comfort” or “Eco” drive mode when practical, especially on the highway. These modes will generally soften throttle response and optimize the transmission for fuel efficiency.

Avoid unnecessary idling. If you’re stopped for more than a minute, it’s generally more fuel-efficient to turn off the engine and restart it than to let it idle. The GLC63 S has an auto start/stop function for this, but it can be disabled, and usually is by its owners.

Keep up with regular maintenance. A well-maintained engine runs more efficiently. This includes changing the oil and air filters at the recommended intervals.