22 MPG combined won’t top any fuel economy charts, but for the 2024 GMC Sierra 1500 equipped with mud-terrain tires, four-wheel drive, and the 3.0L Duramax diesel, it’s a calculated compromise. This Sierra isn’t built for hypermiling; it’s crafted for owners who prioritize capability. Think rural landowners, adventure enthusiasts, and those who regularly tow or haul. They need a truck that can navigate challenging terrain, and they’re willing to trade some MPG for the confidence the Sierra’s configuration provides.

City and highway performance

The EPA estimates the Sierra at 21 MPG in the city and 23 MPG on the highway. These figures highlight an important characteristic of the Duramax diesel: its efficiency doesn’t plummet in stop-and-go traffic as drastically as a large gasoline engine might. The highway number, while seemingly unimpressive, reflects the aerodynamic realities of a truck riding on aggressive mud-terrain tires. Such tires significantly impact airflow and increase rolling resistance, directly hindering fuel economy at higher speeds. The 10-speed automatic transmission helps to maximize low-end torque and keep the engine in its sweet spot at cruising speeds to assist with efficiency.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for this particular configuration of the 2024 GMC Sierra is $2,550. This calculation assumes 15,000 miles of driving per year, with fuel prices based on national averages. Keep in mind that fluctuating fuel costs will impact this number; if diesel prices surge, the actual yearly expense could be substantially higher. Similarly, drivers who cover significantly more or less than 15,000 miles annually will see corresponding changes in their fuel expenditure. For a broader view of all Gmc fuel economy data, take a look at our resources available.

Real-world expectations

While the EPA provides a standardized benchmark, real-world MPG often deviates. Aggressive driving, heavy loads, frequent four-wheel-drive engagement, and aftermarket accessories all take a toll. Owners who frequently use their Sierra for its intended purpose, off-roading, towing, or hauling, should anticipate figures closer to the low end of the EPA’s range. Conversely, those who primarily use it as a daily driver and practice fuel-efficient driving habits may achieve slightly better results. Mud-terrain tires, while excellent for traction, are inherently less efficient than all-season tires. For a more detailed study into SIERRA MPG across all years, we have the numbers.

How it compares

Compared to its competitors, the diesel Sierra occupies a unique space. A similarly equipped Ford F-150 PowerBoost hybrid, while offering superior combined MPG (around 25 MPG), comes with a different set of trade-offs in terms of initial cost and off-road capability. A Ram 1500 with the EcoDiesel engine (around 24 MPG combined) offers similar fuel economy, but with different driving dynamics and interior styling that may sway a perspective buyer. A gasoline-powered Toyota Tundra with four-wheel drive typically hovers around 18 MPG combined, highlighting the diesel’s efficiency advantage. The key consideration for the Sierra buyer is whether the Duramax diesel’s torque, towing capacity, and relative fuel efficiency justify the diesel premium and any associated maintenance costs. The buyer needs to determine if they want to buy any gasoline alternatives for this class of vehicle and prioritize their use.

Tips to maximize efficiency

Diesel engines respond well to smooth, deliberate acceleration. Avoid aggressive starts and hard braking, as these actions waste fuel. Gradual acceleration allows the engine to operate more efficiently and reduces the amount of fuel injected into the cylinders. Anticipate traffic flow and adjust your speed accordingly, driving in a manner that is more conscious of your surroundings.

Tire pressure plays a critical role in fuel economy. Ensure your mud-terrain tires are inflated to the manufacturer’s recommended pressure, which can be found on the doorjamb sticker or in the owner’s manual. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Properly inflated tires will also assist in the longevity of the tread itself.

Avoid unnecessary idling. Modern diesel engines are designed to shut off automatically when idling for extended periods and restart when needed. If you anticipate being stationary for more than a minute or two, turn off the engine. Idling consumes fuel without providing any forward motion or benefit.

While the four-wheel-drive system is invaluable in challenging conditions, it significantly increases fuel consumption. Only engage four-wheel-drive when necessary, such as on snow-covered roads or off-road trails. Driving in four-wheel-drive on dry pavement places unnecessary strain on the drivetrain and wastes fuel. Consider two-wheel drive modes to assist in fuel savings if the road conditions allow for it.

Regular maintenance is critical for optimal fuel economy. Ensure the engine receives scheduled oil changes, air filter replacements, and fuel filter servicing to maintain peak performance and efficiency. Clogged air and fuel filters restrict airflow and fuel delivery, forcing the engine to work harder and burn more fuel. Consider cleaning the fuel injectors periodically.