The 2024 Mercedes-Benz GLS450 4Matic gets 21 MPG combined. To be clear, people don’t buy a GLS450 for fuel efficiency. They choose it for its opulent cabin, its quiet ride quality, the Mercedes star, and its presence. It’s a status symbol first, a family hauler second, and not an efficiency champ. The 21 MPG is the price of admission.

City and highway performance

The EPA estimates 19 MPG in city driving and 24 MPG on the highway. This split shows the GLS450’s strengths and weaknesses. The city figure shows the penalty for driving a large, luxurious vehicle exceeding 5,300 pounds in stop-and-go traffic. The 24 MPG highway figure shows the efficiency of the 3.0L inline-six cylinder engine and 9-speed automatic transmission at steady speeds. The engine’s mild-hybrid system provides some electric assistance, which helps at highway speeds by assisting with coasting and power delivery, subtly improving fuel consumption. This vehicle feels more relaxed and efficient during longer trips than navigating city streets.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2024 Mercedes-Benz GLS450 4Matic at $2,750. This figure is based on driving 15,000 miles per year and using national average fuel prices. Your actual fuel costs will vary depending on driving habits, fuel type, and location. This number illustrates that owning a large vehicle comes with a financial cost beyond the purchase price. GLS450 buyers likely have factored this trade-off into their budget.

Real-world expectations

While the EPA estimates provide a baseline, real-world fuel economy for the GLS450 4Matic often falls short. Aggressive driving, frequent short trips, and heavy air conditioning can negatively impact fuel consumption. Owners who prioritize comfort and performance over efficiency will likely see numbers closer to the city estimate, even in mixed driving. Drivers who adopt a relaxed driving style and spend time on the highway might approach the EPA’s highway number. Expect to visit the gas station regularly in this vehicle.

How it compares

The GLS450 is in a competitive segment where fuel economy often takes a backseat. The BMW X7 xDrive40i, with its similar inline-six engine, achieves 21 MPG combined. V8 models of the GLS (GLS580) or X7 reduce efficiency, often dropping into the mid-teens. all Mercedes Benz fuel economy data reveals that smaller SUVs like the GLE offer better fuel economy, but lack the GLS’s third row. The Land Rover Range Rover typically returns lower MPG figures, especially in its non-hybrid configurations. The Volvo XC90 Recharge, a plug-in hybrid, can improve fuel economy, but costs more and requires regular charging. These comparisons show the trade-offs: buyers choose between size, power, luxury, and efficiency. Those specifically interested in GLS450 MPG across all years can find more specific information.

Tips to maximize efficiency

Use the GLS450’s ECO drive mode. This setting optimizes the engine and transmission for fuel efficiency by smoothing throttle response and shifting at lower RPMs. It might reduce performance, but it can make a difference.

Ensure tires are properly inflated. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Check tire pressure regularly and maintain the recommended inflation level.

Avoid unnecessary idling. Modern engines are designed to be efficient, and restarting them consumes less fuel than idling. If waiting for more than a minute or two, turn off the engine.

Be mindful of your driving style. Aggressive acceleration and hard braking consume significantly more fuel than smooth inputs. Anticipate traffic flow and maintain a consistent speed whenever possible. Use cruise control on the highway to maintain a consistent speed.

Lighten the load. Removing unnecessary items from the car’s trunk and cargo area reduces the vehicle’s weight, improving fuel economy. It may seem minor, but incremental changes add up.