14 MPG combined is not a typo. That figure represents the EPA’s estimate for the 2016 Mercedes-Benz AMG GL63, a vehicle as much about ferocious performance as it is about hauling kids to soccer practice. This SUV, with its hand-built 5.5L twin-turbo V8, caters to a specific clientele: those who demand the utility and luxury of a three-row, while refusing to compromise on outright speed and presence. Fuel efficiency is, shall we say, further down the list of priorities.

City and highway performance

The official EPA estimates peg the GL63 AMG at 13 MPG in the city and 17 MPG on the highway. The city figure reflects the engine’s thirst when negotiating stop-and-go traffic, its considerable weight, and the aggressive tuning of the AMG-enhanced transmission. The highway number, while marginally better, still underscores the aerodynamic limitations of a large SUV relentlessly pushing air at 70+ MPH. These figures are not aspirational; they are a direct consequence of the power and performance on tap, and accepted as such by most GL63 owners.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for the 2016 Mercedes-Benz AMG GL63 is $4,150. This calculation is based on driving 15,000 miles per year and using the national average fuel price for premium gasoline, which this engine requires. If you drive more than 15,000 miles annually, or if fuel prices in your area are higher than the national average, expect to spend even more. This is a substantial fuel bill, but not unexpected for a vehicle of this caliber, purpose, and performance capability. If you’re constantly hammering the accelerator, expect this cost to be even higher.

Real-world expectations

While the EPA figures provide a benchmark, real-world MPG for the GL63 AMG varies significantly based on driving style. A lead foot will easily drop the combined MPG into the single digits, particularly in urban environments. Mellow highway cruising might yield slightly better than the 17 MPG estimate, but sustained high-speed driving will negate any gains. Terrain also plays a role; mountainous routes will stress the engine and drivetrain, impacting fuel efficiency. Consider the EPA numbers as a best-case scenario under ideal conditions. Checking out AMG MPG across all years, you’ll see that performance and efficiency are often at odds.

How it compares

Competitors in the high-performance, three-row SUV segment include the BMW X5 M (around 16 MPG combined) and the Range Rover Sport SVR (also hovering around 15 MPG combined). These vehicles offer similar blends of luxury, performance, and fuel inefficiency. The Porsche Cayenne Turbo S, while not strictly a direct competitor due to its higher price point and slightly different character, delivers around 17 MPG combined thanks mostly to a more modern engine. The GL63’s slightly lower MPG stems from its engine’s design and tuning philosophy, which prioritizes raw power delivery over outright efficiency. For buyers in this segment, a single MPG difference is unlikely to be a deciding factor. This is about compromise, and choosing only the exact blend of performance, practicality, and prestige. See all Mercedes Benz fuel economy data to contextualize the GL63 within the brand’s overall lineup.

Tips to maximize efficiency

Gentle acceleration is key. The GL63 AMG’s twin-turbo V8 is incredibly responsive, but using that power sparingly can significantly improve fuel economy, especially in city driving. Avoid abrupt starts and stops, and try to anticipate traffic flow to maintain a consistent speed.

Monitor tire pressure regularly. Underinflated tires increase rolling resistance, forcing the engine to work harder and consuming more fuel. Refer to the sticker on the driver’s side doorjamb for the recommended tire pressure, and check it at least once a month.

Minimize unnecessary weight. Carrying extra cargo adds to the vehicle’s load, reducing fuel efficiency. Remove any items from the trunk or cargo area that you don’t need on a regular basis. A lighter vehicle is inherently more efficient, even with a powerful engine.

Service the vehicle on time, every time. A well-maintained engine runs more efficiently. Follow the manufacturer’s recommended service schedule for oil changes, air filter replacements, and other maintenance items. Neglecting maintenance can lead to decreased performance and reduced fuel economy.

Employ the ‘Comfort’ driving mode when possible. While the ‘Sport’ and ‘Sport+’ modes unleash the full potential of the AMG engine, they also prioritize performance over fuel efficiency. For everyday driving, stick to ‘Comfort’ mode to optimize fuel consumption without sacrificing everyday drivability.