16 MPG combined. Let’s be honest: That’s the headline figure you need to acknowledge before even considering the 2021 GMC Yukon XL 4WD with the 6.2L V8. This isn’t a vehicle purchased for Prius-like efficiency. It’s a tool, bought by families who need serious passenger and cargo space, often towing boats or campers on weekends. Those buyers willingly trade fuel economy for capability and the commanding presence that only a large SUV can provide.

City and highway performance

The EPA estimates suggest 14 MPG in the city and 19 MPG on the highway. These figures directly reflect the Yukon XL’s weight, the displacement of its V8, and the realities of moving a three-ton vehicle through stop-and-go traffic or at sustained highway speeds. The 10-speed automatic transmission helps optimize engine RPM for efficiency, but even with technologies like cylinder deactivation that shuts down cylinders under light loads, physics ultimately dictates the outcome. The “XL” designation itself adds length and weight compared to the standard Yukon, further impacting fuel consumption. No one should expect significantly better performance from a large, body-on-frame 4WD SUV, given its purpose.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for this Yukon XL configuration is $3,600. This figure is based on driving 15,000 miles per year, with 55% of those miles driven in the city and 45% on the highway, and using the national average fuel price for regular unleaded gasoline at the time of calculation. Keep in mind that this is an estimate; your actual fuel costs will vary depending on your driving habits, local fuel prices, and how frequently you use the Yukon XL for towing or hauling heavy loads. If most of your driving is stop-and-go in a major city, expect to exceed that $3,600 figure. Conversely, if you do a lot of steady-state highway driving, especially without a trailer, you might come in slightly under.

Real-world expectations

While the EPA provides a standardized benchmark, real-world fuel economy can fluctuate considerably. Drivers who frequently use the Yukon XL’s towing capacity or engage the 4WD system will see their MPG plummet. Aggressive driving habits, like rapid acceleration and hard braking, will also reduce fuel economy. However, those who adopt a gentle driving style and maintain consistent speeds may find they can approach or even slightly exceed the EPA’s highway estimate.

Tire pressure is also important, as is keeping up with scheduled maintenance to ensure the engine is running optimally. Payload has an impact, too. Hauling kids and cargo will reduce efficiency, but not nearly as much as towing a boat.

How it compares

Large, body-on-frame SUVs aren’t known for fuel efficiency. A 2021 Ford Expedition with the EcoBoost 3.5L V6 and 4WD gets an EPA-estimated 19 MPG combined, a slight edge. The Chevrolet Tahoe, mechanically similar to the Yukon, posts near-identical figures in models equipped with the 6.2L V8. Even the smaller, more modern Nissan Armada only manages around 15 MPG combined. Buyers cross-shopping these vehicles are typically more concerned with interior space, towing capacity, and features than a marginal difference of one or two MPG. If fuel costs are a primary concern, a minivan or a smaller, unibody SUV would be a more logical choice, sacrificing the capability and size that brings these buyers to consider the YUKON MPG across all years. For those interested in seeing all Gmc fuel economy data, it’s clear where the Yukon XL fits.

Tips to maximize efficiency

The first and most critical step is to adopt a smooth, deliberate driving style. Avoid sudden acceleration and braking. Anticipate traffic flow and maintain a consistent speed whenever possible. The Yukon XL is heavy, and every abrupt change in momentum requires significant energy, and therefore fuel.

Keep an eye on your tire pressure. Underinflated tires increase rolling resistance, forcing the engine to work harder and burn more fuel. Consult the sticker on your driver’s side doorjamb for the recommended tire pressure and check it regularly, especially during temperature changes.

Minimize idling. If you’re stopped for more than a minute or two, turn off the engine. Modern engines are designed to restart quickly and efficiently, and idling wastes fuel without providing any benefit. The Yukon XL’s engine displacement means it consumes significantly more fuel at idle than smaller vehicles.

Be mindful of your cargo and towing habits. Remove any unnecessary weight from the vehicle and avoid carrying items on the roof when possible. When towing, distribute the load evenly and ensure the trailer’s tires are properly inflated. Reducing aerodynamic drag also helps, so keep the speed in check.

Use the vehicle’s drive mode selector wisely. If you’re not actively needing 4WD, keep it in 2WD mode. Engaging 4WD increases drivetrain friction and reduces fuel economy. Only switch to 4WD when encountering slippery conditions or off-road situations that demand the extra traction.