The 2023 GMC Sierra 4WD with the optional 3.0L Duramax diesel and mud-terrain tires gets 22 MPG combined. Don’t dismiss this number without context: this is a full-size truck equipped for serious off-road excursions, not a hybrid hatchback. The buyer seeking this particular Sierra prioritizes capability and ruggedness over maximizing trips between fill-ups, viewing fuel cost as a necessary expense for the versatility and image it provides.

City and highway performance

The EPA estimates the Sierra at 21 MPG in the city and 23 MPG on the highway. These figures are reasonably consistent, reflecting the advanced ten-speed automatic transmission’s ability to keep the engine operating efficiently across diverse driving conditions. In stop-and-go situations, the diesel’s abundant low-end torque minimizes the need for aggressive acceleration, contributing to respectable city fuel consumption. Out on the open road, the transmission optimizes highway cruising, keeping the engine within its most efficient RPM range.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2023 GMC Sierra with the 3.0L Duramax diesel at $2,550. This figure is based on driving 15,000 miles per year, incorporating a mix of 55% city and 45% highway driving, and using the prevailing national average fuel prices at the time of calculation. Individual fuel costs will vary based on driving habits, local fuel prices, and the actual proportion of city versus highway miles driven. If you drive significantly more miles than average, or live in an area with higher fuel prices, your annual cost will exceed this estimate.

Real-world expectations

While EPA estimates provide a standardized benchmark, real-world fuel economy often deviates. The Sierra’s mud-terrain tires enhance off-road performance, but introduce increased rolling resistance compared to standard all-season tires. Aggressive driving, frequent off-roading, or towing will further decrease fuel efficiency. Conversely, gentle acceleration, consistent highway speeds, and diligently maintained tire pressure can yield results closer to, or even slightly exceeding, the EPA estimates.

How it compares

The fuel economy positions the 2023 Sierra 3.0L Duramax with 4WD and mud terrain tires competitively within its segment, and it highlights trade-offs. For example, the Ford F-150 with the 3.5L EcoBoost V6 and 4WD achieves around 20 MPG combined. That’s close, but it doesn’t offer the same low-end torque and potential longevity benefits diesel powertrains can provide. The Ram 1500 with the 3.0L EcoDiesel once achieved 24 MPG combined, but this engine has been discontinued. Examining SIERRA MPG across all years highlights the 3.0L Duramax as one of the most efficient options available for a truck of this size. For those considering other brands, all Gmc fuel economy data can be helpful in your decision.

Tips to maximize efficiency

Monitor your tire pressure regularly. Mud-terrain tires require specific pressures to optimize both on-road performance and fuel economy. Consult the sticker located on the driver’s side door jamb for the recommended pressure, and check your tires at least once a month. Underinflated tires increase rolling resistance, which translates to reduced fuel efficiency and premature tire wear.

Anticipate traffic flow and avoid aggressive acceleration and braking. The Sierra’s diesel engine provides ample torque, allowing for smooth and gradual acceleration. Unnecessary hard acceleration or sudden stops wastes fuel and puts added strain on the powertrain and drivetrain.

Minimize idling time. Diesel engines, while more efficient than gasoline engines at idle, still consume fuel unnecessarily when idling. If you anticipate being stopped for more than a minute, consider turning off the engine. Modern diesel engines are designed to restart quickly and reliably.

When possible, remove any unnecessary weight from the truck bed. Excess weight puts additional strain on the engine and reduces overall fuel efficiency. Removing items like tools, equipment, or cargo when not needed will lighten the load and improve MPG.

Consider using cruise control on the highway. Cruise control helps maintain a consistent speed, minimizing unnecessary acceleration and deceleration. This can lead to noticeable improvements in highway fuel economy, especially on long trips.