An EPA-estimated 24 MPG combined is respectable for the 2024 GMC Sierra 4WD with the 3.0L Duramax diesel engine. This isn’t a compact crossover; it’s a full-size truck designed for serious work and play, this efficiency figure shows the engine’s design and the Sierra’s overall engineering.

City and highway performance

The numbers break down to 23 MPG in the city and 27 MPG on the highway. City driving often reduces fuel economy, but the Duramax’s low-end torque and the smooth 10-speed automatic transmission help maintain efficiency even when navigating stop-and-go traffic. That 27 MPG highway figure is where this truck excels, especially for those who frequently use their Sierras for long hauls, commutes, or towing campers down the Interstate. The 10-speed transmission keeps the engine spinning at its most efficient speed, maximizing fuel savings on extended drives. This is a marked improvement over older Sierras, demonstrating the gains realized by modern diesel technology. See SIERRA MPG across all years.

Annual fuel cost

The EPA estimates an annual fuel cost of $2,300 for this particular configuration of the Sierra. This figure is calculated based on driving 15,000 miles per year, using current national average fuel prices. Your actual fuel cost will vary depending on how many miles you drive and where you live, as fuel prices fluctuate regionally. Still, the $2,300 provides a standardized point of comparison against other vehicles. If you tow frequently, live in an area with consistently high fuel prices, or rack up significantly more than 15,000 miles annually, expect to spend more. Conversely, lighter use or living in an area with lower prices will reduce the annual cost. It’s a useful benchmark.

Real-world expectations

EPA estimates are a good starting point, but real-world MPG can vary. Factors like driving style, terrain, and load significantly affect the numbers you’ll see on your dashboard. Someone consistently hauling heavy loads or driving aggressively will experience lower fuel economy. A driver with a light foot, who anticipates traffic and avoids hard acceleration, will likely see numbers closer to, or even exceeding, the EPA estimates. Terrain matters, too; driving in mountainous areas will significantly decrease fuel economy compared to flat highway driving. The Sierra’s onboard trip computer provides real-time and average fuel economy data, allowing drivers to monitor their consumption habits and adjust accordingly.

How it compares

Compared to other full-size trucks, the 2024 GMC Sierra 4WD 3.0L Duramax excels in fuel efficiency. For example, the Ford F-150 with the 3.5L EcoBoost V6 and 4WD achieves around 20 MPG combined, though figures can vary depending on the specific trim and axle ratio. The Ram 1500 with the eTorque V6 and 4WD lands in a similar range, often around 21-22 MPG combined. The Toyota Tundra, known for its reliability, typically hovers around 19 MPG combined with its standard V6 engine and 4WD. These differences, though seemingly small, add up over time, resulting in significant fuel savings for the Sierra owner. The Sierra 3.0L Duramax offers impressive torque figures, ensuring it doesn’t sacrifice capability for efficiency. This is a critical factor for truck buyers who need both.

Tips to maximize efficiency

Proper tire inflation is critical for maximizing fuel economy. Check your tires regularly and maintain the pressure recommended on the doorjamb sticker. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Since many Sierra owners use their trucks for both work and recreation, they should adjust tire pressures accordingly, choosing higher pressures for highway cruising and lower pressures (within safe limits) for off-road use.

Avoid aggressive driving habits, such as rapid acceleration and hard braking. Smooth, gradual throttle inputs and anticipating traffic flow not only improve fuel economy but also reduce wear and tear on the vehicle’s components. With the Duramax’s abundance of low-end torque, it doesn’t require heavy throttle application to get up to speed, making it easier to drive efficiently.

Regular maintenance is essential for keeping the engine running efficiently. Follow the manufacturer’s recommended service schedule for oil changes, air filter replacements, and other critical maintenance items. A clean air filter ensures proper airflow to the engine, and fresh oil reduces friction, both contributing to improved fuel economy. The Duramax diesel requires specific maintenance procedures, so adhering to the maintenance schedule is particularly important.

When towing, use the Tow/Haul mode strategically. This mode optimizes the transmission shift points and engine management for hauling heavy loads, improving performance and reducing strain on the powertrain. While Tow/Haul mode can decrease overall fuel economy, it helps maintain efficiency by preventing the engine from lugging or over-revving. It’s a tradeoff, but using Tow/Haul mode judiciously will extract the best possible MPG while towing. Explore all Gmc fuel economy data.