The 2022 Mercedes-Benz GLS450 4Matic gets 20 MPG combined. While this number might get attention as more drivers focus on lower fuel costs, it’s important to consider what this vehicle is. It’s not a compact hatchback; it’s a large, luxurious SUV made to transport families and cargo in great comfort and style. GLS owners prioritize space, safety, and prestige over fuel savings. They know the trade-off, and the vehicle’s features are often worth the cost of fuel.

City and highway performance

The EPA estimates the GLS450 4Matic gets 18 MPG in the city and 24 MPG on the highway. The city figure reflects urban driving conditions, where the vehicle’s weight and frequent stops affect efficiency. The highway number is better; the GLS cruises with reasonable efficiency thanks to its smooth 9-speed automatic transmission. This transmission helps keep the engine at optimal RPMs for fuel efficiency at higher speeds. These numbers are expected for a vehicle of this size, and knowing them is the first step to managing fuel consumption.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2022 Mercedes-Benz GLS450 4Matic is $2,900. This is based on driving 15,000 miles per year, with 55% in the city and 45% on the highway. The calculation also uses the national average fuel price during EPA testing. Actual fuel costs will vary depending on driving habits and local fuel prices, but this number offers a standard for comparison. Given the vehicle and its target owner, this cost is likely acceptable.

Real-world expectations

EPA testing has a consistent method, but real-world fuel economy often differs from official numbers. Many things impact MPG, including driving style, tire pressure, temperature, and terrain. Hard acceleration, hard braking, and long idling will hurt fuel efficiency in the GLS450. Smooth driving, correct tire inflation, and avoiding idling can help you get closer to, or even slightly better than, EPA estimates. Passenger and cargo weight also affect fuel consumption.

How it compares

The 2022 Mercedes-Benz GLS450 4Matic’s fuel economy is similar to other large luxury SUVs. For example, the BMW X7 xDrive40i, another six-cylinder rival, has an EPA combined rating of 21 MPG. The Volvo XC90 T6 AWD gets around 22 MPG combined. A Cadillac Escalade with its larger V8 gets less, around 16 MPG combined. Buyers in this group often accept these compromises, and they want the space, luxury, and performance these vehicles provide. If fuel economy is a main concern, they might consider a hybrid or smaller SUV, but the GLS450 buyer is usually focused on other things. See GLS450 MPG across all years on this site.

Tips to maximize efficiency

GLS450 driving modes can help. “Comfort” or “Eco” modes will adjust the engine and transmission for fuel efficiency, possibly resulting in savings, particularly on long trips. Avoid hard acceleration and braking; these use more fuel. Gentle inputs will help the engine run more efficiently.

Keep tires properly inflated. Underinflated tires increase rolling resistance, which reduces fuel economy. Check tire pressure regularly and inflate them to the recommended levels, found on a sticker inside the driver’s side door jamb.

Avoid idling. Idling wastes fuel and creates emissions. If you expect to wait for more than a minute, turn off the engine. Modern engines restart quickly, so you won’t cause wear and tear.

Remove extra weight. Extra cargo adds weight and reduces fuel economy. Remove items you don’t need to lighten the load and improve your MPG. Removing a rooftop carrier when not in use will also help a lot.

Keep up with maintenance. Regular oil changes, air filter replacements, and spark plug maintenance ensure the engine runs well. A well-maintained engine will always get better fuel economy than one that is neglected. Be sure you browse all Mercedes Benz fuel economy data to compare to other models if efficiency is your priority.