18 MPG combined won’t top any fuel efficiency lists, but for the 2023 Mercedes-Benz GLS580 4matic, it’s part of the deal. This very capable three-row SUV includes a twin-turbo V8 engine and luxury features that rival a private jet. People buy this vehicle for its effortless power, its presence, and its comfortable interior, not for its fuel consumption. GLS580 buyers understand and accept this trade-off.

City and highway performance

The EPA estimates the GLS580 will get 16 MPG in the city and 21 MPG on the highway. The city number reflects the engine’s higher fuel consumption during frequent stops and starts. The highway number, while still modest, is achievable because the engine operates more efficiently at consistent speeds. The 9-speed automatic transmission shifts quickly into higher gears, which helps keep the RPMs lower and saves fuel, especially on long highway drives.

Annual fuel cost

The EPA says the annual fuel cost for the 2023 Mercedes-Benz GLS580 is $3,200. This is based on driving 15,000 miles per year and using national average fuel prices. Remember that this number can change based on your driving habits and location. Those who drive aggressively or in stop-and-go traffic will likely exceed this estimate, while those who mainly drive on the highway may see slightly lower costs. Premium fuel is recommended for the GLS580’s engine, which significantly impacts the total cost.

Real-world expectations

The EPA provides a standardized testing method, but real-world fuel economy can vary. Drivers who frequently the GLS580’s power for fast acceleration or towing will likely see numbers below the EPA estimates. However, careful drivers who anticipate traffic and avoid aggressive driving may achieve numbers at or slightly above the EPA’s projections. The all-wheel-drive system provides better traction, but it also slightly reduces fuel economy compared to a two-wheel-drive system. For more information, see GLS580 MPG across all years.

How it compares

The GLS580’s fuel economy is similar to other high-performance luxury SUVs. The BMW X7 M60i, with its similar V8 engine, gets an EPA-estimated 16 MPG combined. The Land Rover Range Rover P530, another luxurious and capable SUV, gets around 18 MPG combined with its V8. Even the Cadillac Escalade, with its more efficient diesel engine, only manages about 22 MPG combined. Buyers in this market segment focus on performance and luxury over fuel savings, which is why manufacturers invest more in horsepower than hybrid technology. If less gas is a priority, consider looking at all Mercedes Benz fuel economy data to find a more efficient vehicle.

Tips to maximize efficiency

The GLS580 isn’t designed for fuel efficiency, but owners can take steps to improve it. Gentle acceleration and anticipating traffic are important. Avoid sudden starts and stops, as these make the engine consume more fuel. The GLS580’s driving modes can also be used for efficiency, allowing the driver to prioritize efficiency through the drive mode selector.

Regular maintenance is critical for good fuel economy. Make sure the tires are properly inflated, as underinflated tires increase rolling resistance and reduce MPG. Scheduled maintenance, such as oil changes and air filter replacements, will also help the engine run efficiently.

Reduce extra weight inside the vehicle. Unnecessary items in the cargo area or cabin add to the vehicle’s weight, making the engine work harder. Removing extra weight can slightly improve fuel economy.

Adjust your highway driving style. Maintaining a consistent speed and avoiding sudden acceleration can improve fuel economy. Cruise control on long road trips can help keep the engine running efficiently and save fuel.