The 2019 GMC Sierra K10 4WD AT4 with the 5.3L V8 gets a combined 17 MPG. This might seem high in a world of hybrid pickups and efficient SUVs, but it reflects this Sierra’s purpose: providing off-road capability and strong style without completely sacrificing the practical benefits of a full-size truck. AT4 buyers are prioritizing ground clearance, four-wheel drive traction, and the aggressive look that sets this trim apart. It’s a calculated trade-off.

City and highway performance

The 2019 Sierra AT4’s EPA ratings break down to 15 MPG in the city and 20 MPG on the highway. The city figure highlights the fuel demands of stop-and-go traffic, where the truck’s weight and the engine’s thirst become most apparent. The highway number, while better, still isn’t excellent. The Sierra’s aerodynamics, while improved over previous generations, are limited by its size and boxy shape. The 8-speed automatic transmission does its best to keep the engine in its most efficient operating range, but the reality of propelling a truck with this much mass down the road at 70+ MPH is inescapable.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2019 GMC Sierra AT4 at $2,600. This is based on driving 15,000 miles per year, with a mix of city and highway driving, and using national average fuel prices. Individual fuel costs will vary based on driving habits, location, and fluctuating gas prices. However, the $2,600 provides a useful benchmark for understanding the long-term cost of ownership. Buyers should consider this figure alongside other expenses like insurance, maintenance, and potential repairs when budgeting for their truck.

Real-world expectations

While the EPA numbers provide a baseline, real-world fuel economy can vary significantly. Owners who spend a majority of their time in urban environments, frequently tow trailers, or consistently drive aggressively will likely see numbers closer to the 15 MPG mark, or even lower. Conversely, those who primarily use their Sierra for highway cruising, maintain a steady speed, and avoid heavy acceleration may be able to approach, or even slightly exceed, the 20 MPG highway rating. Factors like tire pressure, vehicle maintenance, and even weather conditions can also play a role in achieved fuel economy.

How it compares

Compared to other full-size, four-wheel-drive trucks, the 2019 Sierra AT4’s fuel economy is generally comparable, though some variations exist. A similarly equipped 2019 Ford F-150 with the 5.0L V8 and four-wheel drive achieves roughly equivalent EPA ratings, around 17 MPG combined. The Ram 1500 with the 5.7L Hemi and eTorque mild-hybrid system offers a slight improvement, potentially reaching 19 MPG combined in some configurations. The Toyota Tundra, known for its reliability but not its fuel efficiency, often lags behind, commonly achieving around 15 MPG combined with its 5.7L V8 in 4×4 trim. For consumers contemplating different generations of the truck, check out SIERRA MPG across all years to inform the decision.

Tips to maximize efficiency

The Sierra AT4 isn’t designed to be a fuel-sipping champion, but there are still steps owners can take to improve fuel economy. Avoid aggressive acceleration and hard braking. Smooth, progressive driving will significantly reduce fuel consumption, especially in city driving. Use cruise control on the highway to maintain a consistent speed and minimize unnecessary throttle inputs.

Regularly check and maintain your tire pressure. Underinflated tires increase rolling resistance, which directly impacts fuel economy. Consult the sticker on your driver’s side doorjamb for the recommended tire pressure for your Sierra AT4. Also remember to maintain your car according to suggested intervals.

Consider limiting the use of four-wheel drive to situations where it’s genuinely needed. Driving in 4WD on dry pavement increases friction and reduces fuel economy. Keep the system in two-wheel drive whenever possible to minimize drivetrain losses.

Remove any unnecessary weight from the truck bed or cab. Extra weight increases the engine’s workload, leading to higher fuel consumption. Clearing out tools, equipment, or other items that aren’t essential can make a noticeable difference over time. For all Gmc fuel economy data, visit our brand hub.