18 MPG combined is what you get with the 2018 GMC Yukon K1500 XL 4WD with the 5.3L V8. It’s a number that separates those who seriously need the Yukon XL’s large cargo space and towing capacity from those who just want a big SUV. This isn’t a vehicle you buy to save money on fuel. It’s a tool, and using the tool means you will use a lot of gasoline.

City and highway performance

The EPA estimates the 2018 Yukon XL 4WD at 15 MPG in the city and 22 MPG on the highway. The difference reflects the demands on the 5.3L V8. Stop-and-go traffic requires constant acceleration, which reduces any potential fuel-saving. The engine works harder to get moving, then immediately idles at a stop. On the open road, at a steady cruising speed, the Yukon XL does better, benefiting from technologies like Active Fuel Management (cylinder deactivation), which allows the engine to run on just four cylinders under light load. However, its size and weight mean that even on the highway, aerodynamic drag and rolling resistance are factors, preventing it from achieving better numbers.

Annual fuel cost

The EPA says the estimated annual fuel cost for the 2018 GMC Yukon K1500 XL 4WD is $2,450. This is based on driving 15,000 miles per year, with 55% of those miles driven in the city and 45% on the highway. The calculation uses the national average fuel price at the time of assessment. Your actual fuel costs will vary depending on your driving habits, local fuel prices, and the type of fuel you use. Premium fuel is not required, so using regular gasoline keeps the cost down.

Real-world expectations

The EPA estimates provide a baseline, but real-world fuel economy for the 2018 Yukon XL 4WD will always vary. Driving hard, frequent towing, and carrying heavy loads will hurt fuel consumption. If you drive smoothly, keep consistent highway speeds, and avoid idling, you may be able to match or slightly exceed the EPA estimates. The vehicle’s age and condition matter. As parts wear and maintenance is neglected, fuel efficiency can drop. Tire pressure is also key, since under-inflated tires increase rolling resistance. The YUKON MPG across all years has remained largely the same, so expect similar numbers from other model years.

How it compares

The fuel economy of the 2018 GMC Yukon XL 4WD is typical for its segment. The Ford Expedition Max with its 3.5L EcoBoost V6 gets slightly better numbers, around 17 MPG city and 23 MPG highway for the 4WD version. A Chevrolet Suburban, the same vehicle as the Yukon XL, will have similar MPG numbers. A Toyota Sequoia, with its older V8, typically yields numbers closer to 13 city and 17 highway. If you are considering a vehicle in this class you understand the trade-off between capability and fuel efficiency. They want passenger and cargo space, towing, and the feeling of security that comes with a big SUV. For those more concerned about fuel efficiency, there are more economical SUV options, though they usually do not have the Yukon XL’s size and towing. Always compare all Gmc fuel economy data before making a buying decision.

Tips to maximize efficiency

Maintenance is important for good fuel economy. Keep the engine tuned, change the air filter regularly, and make sure all fluids are at the right levels. A maintained engine runs better, reducing fuel use.

Check your tire pressure. Under-inflated tires increase rolling resistance, forcing the engine to work harder and burn more fuel. Check tire pressure often and inflate to what the manufacturer says, which is on a sticker inside the driver’s side door.

Avoid driving hard. Fast acceleration, hard braking, and speeding all use fuel. Smooth driving at normal speeds will improve fuel economy. Watch traffic and brake early to avoid sudden stops. Using cruise control on the highway also helps you keep a steady speed, which promotes efficiency.

Don’t idle. Leaving the engine running while stopped wastes fuel. If you expect to be stopped for more than a minute or two, turn off the engine. Modern starters can handle frequent starts.

Consider the weight you’re hauling. The Yukon XL is built to carry people and cargo, but the lighter you travel, the better your mileage will be. Remove items that aren’t needed for the trip, and if your roof rack is empty, remove it to reduce drag.