What MPG does a 3.0 Duramax get?

The 3.0-liter Duramax inline-6 diesel typically delivers about 23 mpg in city driving, around 33 mpg on the highway, and a combined figure in the mid- to high-20s, with small variations depending on drivetrain and model year.

The following article breaks down the EPA fuel-economy estimates for GM’s 3.0L Duramax used in Silverado 1500 and Sierra 1500 pickups, and explains how real-world mileage can vary with configuration, load, and driving conditions.

EPA ratings by drivetrain

EPA estimates published for current 3.0L Duramax-powered pickups differentiate between 2WD and 4WD configurations. The figures below reflect typical crew-cab arrangements with common bed lengths and the 10-speed automatic transmission used in recent years.

• 2WD Crew Cab: about 23 mpg city / 33 mpg highway / about 27 mpg combined


• 4WD Crew Cab: about 23 mpg city / 30 mpg highway / about 25–26 mpg combined

These figures are representative values; actual results depend on model year, cab/bed configuration, and equipment choices.

What affects real-world MPG?

In practice, several factors can push mileage above or below the EPA numbers. The most impactful include:

• Driving style and speed


• Towing heavy loads or carrying a full payload


• Terrain, grade, and altitude


• Aerodynamics and sustained high-speed driving


• Vehicle maintenance and airflow (filters, tires, wheel size)


• Accessory usage such as air conditioning and heating

To maximize efficiency, follow manufacturer guidance on tires, fluids, and maintenance, and adopt conservative driving habits where possible.

Summary

The 3.0 Duramax generally lands in the 20s to mid-20s for combined fuel economy, with EPA estimates commonly around 23 mpg city, 33 mpg highway, and about 27 mpg combined for 2WD configurations, while 4WD setups tend to yield slightly lower combined numbers. Real-world results will vary based on year, configuration, and driving conditions.

How does the Duramax 3.0 compare to the 5.3 gas mileage?

3.0L Turbo Diesel 6-Cylinder – Torque: 460 lb-ft. 5.3L V8 – RWD Efficiency: Up to an estimated 17/23 city/hwy mpg. 3.0L Turbo Diesel 6-Cylinder – RWD Efficiency: Up to an estimated 23/33 city/hwy mpg.

How do you get 30 MPG on a Duramax?

Achieving 30 mpg on a Duramax is possible through a combination of driving habits, routine maintenance, and potential modifications, though it's easier on the 3.0L version than the 6.6L, and often requires specific, gentle driving techniques. To improve mileage, avoid hard acceleration and idling, use cruise control on the highway, maintain proper tire pressure, and keep the truck well-maintained with clean filters. Aerodynamic aids like bed covers can also help. 
Driving habits

• Drive smoothly: Avoid jackrabbit starts and hard acceleration. Gradual and steady acceleration uses less fuel. 
• Reduce speed: Aerodynamic drag increases significantly at higher speeds. Driving at a lower, steady speed, such as 60-65 mph, is more fuel-efficient. 
• Minimize idling: Avoid prolonged idling, which wastes fuel without moving the vehicle. Turn off the engine during long stops. 
• Use cruise control: On the highway, use cruise control to maintain a consistent speed. 
• Plan your trips: Combine errands, avoid peak traffic times, and plan routes to minimize backtracking. 

You can watch this video to learn how to improve your Duramax's fuel efficiency: 1mSynthetic Oil ProtectionYouTube · Mar 4, 2024
Maintenance and modifications

• Maintain optimal tire pressure: Underinflated tires increase rolling resistance, which can significantly decrease fuel efficiency. Check and maintain proper tire pressure regularly. 
• Perform regular maintenance: Keep your air, fuel, and engine filters clean. Follow the manufacturer's recommended service schedule for your truck. 
• Use quality fluids: Use high-quality, synthetic motor oil that is appropriate for your engine. 
• Add a bed cover: Installing a tonneau cover or a bed cap creates a more aerodynamic shape for the truck, which can improve highway mileage. 
• Consider tuning and fuel system upgrades: Some owners report mileage gains from aftermarket tuning and fuel system upgrades, which can help the engine run more efficiently, especially when properly tuned for economy, as explained in this Facebook discussion. 

Important considerations

• Model matters: Achieving 30 mpg is much more realistic for the lighter 3.0L inline-6 Duramax engine than for the larger 6.6L Duramax. 
• Towing reduces MPG: Towing will significantly lower your fuel economy. 
• "Smiles per gallon": Be aware that aggressive driving, while fun, will drastically reduce fuel mileage. The pursuit of maximum "smiles per gallon" is the enemy of fuel efficiency. 

Why is Chevy discontinuing the 3.0 Duramax?

Chevy is not discontinuing the 3.0L Duramax; rather, it is replacing the older LM2 version with a newer, more powerful LZ0 version. The replacement is due to improvements in performance, fuel efficiency, and emissions, and to address potential issues with the older engine, such as the need to adapt it for the Chevy Tahoe Z71 package.
 

• Engine replacement: General Motors is replacing the 3.0L I6 LM2 engine with the updated 3.0L I6 LZ0 engine. 
• Performance and efficiency: The new LZ0 engine is expected to offer improvements in power, torque, and fuel efficiency. 
• Addressing issues: The new engine is also designed to address some of the older engine's potential faults. For example, the LZ0 engine may have redesigned cooling lines to allow it to fit in the Chevy Tahoe Z71. 
• Production timeline: The production of the LM2 ended, with the final day for ordering the LM2 engine in SUVs being August 8, 2024. The LZ0 engine is scheduled to be the new standard for the 2025 model year and beyond. 

What is the real MPG for a 3.0 Duramax?

Real-world fuel economy for the 3.0L Duramax engine varies, but owners consistently report averages ranging from 25 to 27 MPG for mixed city/highway driving, with some getting over 30 MPG on highway trips. Factors like 2WD vs. 4WD, gear ratio, driving habits, and whether the vehicle has a lift or larger tires significantly influence the mileage. For example, a 2WD model with 3.23 gears can achieve higher highway mileage, while a 4WD with larger tires will likely get lower results.
 
This video shows the real-world fuel economy of a 3.0L Duramax in a GMC Sierra 1500: 57sNikki CovackYouTube · Nov 20, 2024
Typical real-world MPG

• Mixed Driving: Expect to see around 25-27 MPG, with some sources showing averages around 26 MPG for mixed driving over a long period. 
• Highway Driving: On long highway stretches with consistent speeds, it's common to achieve 28-32 MPG, with some drivers reporting even higher numbers. 
• Lower MPG: Your mileage may drop to the low 20s in city-heavy conditions or with a 4WD AT4 model equipped with larger, more aggressive tires. 

Factors that impact MPG

• Drive Wheel Configuration: 2-wheel-drive (2WD) models generally have better fuel economy than 4-wheel-drive (4WD) models. 
• Gear Ratio: Trucks with a less aggressive gear ratio, such as 3.23, tend to perform better at highway speeds compared to those with more aggressive gears like 3.73. 
• Tire Type and Size: Trucks with a lifted suspension or larger, all-terrain/mud-terrain tires will have lower fuel economy compared to models with standard tires. 
• Driving Habits: Aggressive acceleration, high speeds, and heavy towing will reduce fuel efficiency. 
• Vehicle Model: Different models, such as a pickup truck versus an SUV like the Tahoe, will have different MPG ratings. For example, a 2024 Tahoe is rated lower than a comparable Silverado or Sierra pickup.