15 MPG combined is a key consideration when discussing the 2015 Mercedes-Benz GL550 4matic. It’s a noticeable figure, but it’s also understandable for those seeking this particular SUV. The GL550 isn’t bought for its fuel efficiency. It’s chosen for its immense capability, outright luxury, and powerful V8 engine. Buyers prioritize passenger comfort, towing capacity, and effortless power over fuel savings, and typically have the financial means to cover the expense.

City and highway performance

The EPA estimates the 2015 GL550 at 13 MPG in the city and 18 MPG on the highway. These figures reflect the realities of moving a vehicle weighing over 5,500 pounds. City driving primarily measures the engine’s ability to accelerate from a stop, which requires significant energy for a large SUV. The highway MPG, while better, is affected by the GL550’s considerable aerodynamic drag. The 7-speed automatic transmission constantly selects the optimal gear to balance power and efficiency, but still requires significant fuel to maintain highway speeds.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2015 Mercedes-Benz GL550 4matic is $3,850 per year. This is based on driving 15,000 miles annually, with a mix of city and highway driving, and using the national average fuel price. This number serves as a baseline to compare against other vehicles, giving potential buyers an idea of the long-term cost.

Real-world expectations

EPA estimates provide a standardized baseline, but real-world MPG can vary considerably. Aggressive driving, stop-and-go traffic, and extended idling can easily reduce fuel economy below the rated 13 MPG in the city. Gentle highway cruising can increase mileage beyond 18 MPG. Factors like tire pressure, vehicle maintenance, and air conditioning can also affect fuel consumption in the GL550.

Terrain, especially mountainous or hilly areas, will have a large impact, dropping numbers even lower than the 13 MPG rating. Understanding these factors is important when considering the cost of ownership for this sizeable vehicle.

How it compares

The GL550’s fuel economy is lower than its competitors. A 2015 BMW X5 xDrive50i, with its similar V8 engine, achieves a slightly better 17 MPG combined. Even the supercharged Range Rover, known for luxury and off-road capability, achieves 16 MPG combined in V8 form. While the differences may seem small, they result in significant savings over the vehicle’s lifespan. These comparisons matter to buyers who are conscious of the overall cost of ownership, even if fuel economy isn’t their top priority. Buyers can check GL550 MPG across all years to understand long-term trends.

Tips to maximize efficiency

The GL550 has a large engine and consumes a lot of fuel. Regular maintenance, including air filter replacements and spark plug checks, can help the engine run efficiently. Clogged air filters and worn spark plugs decrease fuel efficiency and prevent the engine from fully using the fuel.

Avoid aggressive acceleration and hard braking. The GL550 has plenty of power, so there is no need to accelerate rapidly. A smooth driving style minimizes fuel consumption and helps the vehicle maintain momentum. Anticipate traffic and avoid unnecessary stops.

Ensure tires are properly inflated to the recommended pressure. Low tire pressure increases rolling resistance, making the engine work harder and consume more fuel. Use the tire pressure monitoring system (TPMS) to maintain pressures.

Minimize idling time. Idling burns fuel without covering distance. If you expect to be stopped for more than a minute or two, turn off the engine. Even short periods of idling contribute to fuel consumption, especially in stop and go traffic.

Remove unnecessary weight from the vehicle. The GL550 is already heavy, so extra weight reduces fuel efficiency. Remove unnecessary cargo, such as sports equipment or tools, to lighten the load and improve MPG. You can check all Mercedes Benz fuel economy data to compare to the ratings of other vehicles.