17 MPG combined is what you’ll likely get with the 2019 GMC Sierra K10 4WD AT4 with the 6.2L V8. This truck isn’t about Prius-like efficiency. It’s about an imposing presence, confident off-road capability, and the satisfying rumble of that potent engine. Fuel economy, while certainly not irrelevant, is lower on the priority list than raw capability and a bold statement.

City and highway performance

The EPA estimates for the 2019 Sierra AT4 6.2L 4WD reflect the compromises you’ll find in a large, powerful truck. 15 MPG in the city mirrors the strain of stop-and-go traffic on a heavy vehicle with a thirsty motor. The 10-speed automatic transmission tries its best to optimize fuel, but physics are physics. On the highway, the picture improves slightly to 19 MPG. With less frequent acceleration and more consistent speeds, the engine doesn’t have to work as hard.

Still, aerodynamics and the weight of the 4WD system keep it from being a true fuel sipper.

Annual fuel cost

The EPA estimates that owners of the 2019 GMC Sierra K10 4WD AT4 6.2L will spend $3,400 per year on fuel. This figure is based on driving 15,000 miles annually, with 55% of those miles driven in the city and 45% on the highway. The calculation also uses the national average fuel price at the time of the EPA’s testing. This is a useful benchmark, but individual driving habits and fluctuations in gasoline prices will significantly impact your actual fuel expenses.

Someone who uses their AT4 primarily for short trips around town will likely exceed that figure, while someone who does mostly highway miles and practices careful driving habits might come in under it.

Real-world expectations

While the EPA provides a standardized rating, real-world MPG for the 2019 Sierra AT4 6.2L 4WD will vary considerably. Towing heavy loads, navigating challenging terrain, or simply enjoying the engine’s power will all negatively impact fuel efficiency. On the other hand, smooth acceleration, consistent speeds, and minimizing idling can help you get closer to the EPA estimates. Pay attention to your driving habits and be honest about how you’re using the truck to manage your expectations.

How it compares

The 2019 Sierra AT4 6.2L 4WD’s fuel economy is predictable when compared to others in its class. The Ford F-150 with its 3.5L EcoBoost engine can achieve around 20 MPG combined in 4×4 configuration. However, that’s with a smaller displacement and a turbocharged engine prioritizing efficiency. Ram 1500 models with the 5.7L Hemi engine and eTorque mild-hybrid system also hover around 17-19 MPG combined in 4×4 configuration.

The Toyota Tundra, known for its reliability but not its fuel efficiency, often lags slightly behind, with some trims struggling to reach 15 MPG combined. Someone choosing the AT4 isn’t necessarily cross-shopping for maximum fuel savings; they’re likely prioritizing the Sierra’s distinct styling, strong engine, and off-road features, understanding that it comes at a cost. Reviewing SIERRA MPG across all years can provide further historical context.

Tips to maximize efficiency

The 6.2L V8 responds well to smooth and deliberate acceleration. Avoid stomping on the gas pedal, especially from a standstill. Gentle acceleration will help the 10-speed automatic transmission shift smoothly and keep the engine in its most efficient range without sacrificing too much momentum.

Pay attention to tire pressure. Underinflated tires increase rolling resistance, forcing the engine to work harder and burn more fuel. Check your tire pressure regularly and inflate them to the recommended level found on the driver’s side doorjamb.

Minimize idling. Letting the engine run unnecessarily, especially in cold weather to “warm up,” wastes fuel. Modern engines warm up quickly under load, so it’s generally more efficient to simply start driving after a brief idle period.

Plan your routes strategically. Avoiding congested areas and stop-and-go traffic can significantly improve fuel economy. Consider using navigation apps to find the most efficient routes, even if it means adding a few extra miles.

Reduce unnecessary weight. Hauling around excessive gear, tools, or other items in the bed of the truck or inside the cabin adds weight and decreases efficiency. Remove anything you don’t need to be carrying to improve fuel mileage. Comparing this data alongside all Gmc fuel economy data will reveal the impact of vehicle weight on efficiency.