How many miles per gallon does a 2004 GMC 3500 get?
Fuel economy for a 2004 GMC Sierra 3500 HD varies quite a bit by engine, drivetrain, and configuration. In general, gasoline-powered models land in the low-to-mid teens miles per gallon overall, while diesel versions with the Duramax tend to deliver higher highway efficiency, with combined figures often in the mid-teens to upper teens. Exact numbers depend on cab and bed size, axle ratio, whether the truck is 2WD or 4WD, and how it’s driven or loaded.
Engine options and typical fuel economy ranges
The 2004 3500 HD was offered with several powertrains that influence efficiency. Here’s a snapshot of what owners commonly report, noting that actual numbers depend on configuration, cab size, bed length, and whether the truck is 2WD or 4WD.
- Gasoline 6.0L V8: Typically around 9–12 mpg in the city and 14–18 mpg on highways; combined roughly 12–15 mpg for 2WD models. 4x4 versions can dip a few mpg more.
- Gasoline 8.1L V8: Similar city mileage to the 6.0L but slightly lower highway efficiency; commonly about 9–11 mpg city and 13–17 mpg highway; combined near 12–14 mpg (2WD).
- Diesel 6.6L Duramax (LB7/LLY in 2004): Generally higher highway efficiency, roughly 12–16 mpg city and 18–22 mpg highway; combined around 16–19 mpg, with 4x4 trims a notch lower.
- Drivetrain effect: Two-wheel drive (2WD) typically yields better fuel economy than four-wheel drive (4WD) by a few mpg, and towing or heavy payloads can reduce efficiency by several mpg in any configuration.
Note: These ranges reflect typical reports from owners and historical fuel economy data. Exact numbers for a specific 2004 GMC Sierra 3500 HD will depend on factors such as cab/bed configuration (Regular, Extended, Crew), axle ratio, transmission, and whether the vehicle is equipped with a particulate filter or any towing equipment.
How to estimate the MPG for your exact truck
To gauge your specific truck’s fuel economy, you can track real-world consumption over a period of time and use a simple calculation. This helps account for variables like load, driving style, and terrain that charts or labels may not capture.
- Record the odometer reading and fuel added each time you fill up the tank, along with the number of gallons to refill.
- Repeat the process for several fill-ups (ideally 6–8) to average out short-term fluctuations.
- Calculate miles driven per tank and divide by gallons used per tank to obtain the miles-per-gallon figure, then average across all tanks.
- Note the driving conditions during the period (city vs. highway, towing, heavy payload) to interpret the results in context.
Using your own consumption data over a representative period will give you the most accurate picture of your particular 2004 GMC 3500’s mpg, given its unique setup and usage.
Model-year specifics and caveats
In 2004, the GMC Sierra 3500 HD offered both gasoline engines and the Duramax diesel, with variations in cab sizes and axle configurations. Because heavy-duty trucks of this era often lacked standardized EPA fuel economy labeling, owners rely on real-world logs or manufacturer-era estimates. The exact mpg for any given truck will depend on drivetrain (2WD vs. 4WD), axle ratios, towing equipment, and how the vehicle is used on a day-to-day basis.
Summary
For a 2004 GMC 3500, mpg varies widely by engine and drivetrain. Gas models typically fall in the low-to-mid teens for combined efficiency, while Duramax diesel variants tend to offer higher highway mileage and mixed results around the mid-to-upper teens. To get an exact figure for a specific truck, check the original window sticker or VIN-based fuel economy data, and consider tracking your own fuel use over several fill-ups to account for load and driving style.
How many miles per gallon does a 2004 GMC Sierra 3500 get?
Ultra reliable, easy to get parts, timeless body style, great work horse. Crew cabs will pull 19-20 mpg on the highway no problem (with stock suspension/wheels).
How many miles per gallon does a 3500 diesel get?
Efficiency leaders: Chevrolet/GMC 2500/3500 Duramax 6.6L, Ford F-250/F-350 6.7L, Ram 2500/3500 6.7L. Unloaded highway runs often deliver 17–20 mpg when geared sensibly.
What is the best year for the GMC 3500 diesel?
The best years for a GMC 3500 diesel are the 2006–2007 models with the LBZ engine due to their reliability, power, and lack of complex emissions controls, or the more modern 2017-2023 L5P models for their increased power, though they come with more complex and potentially costly emissions systems. For a balance of power and towing capability without the more complex emissions equipment of the L5P, the 2011–2016 LML models are also a strong choice, but the CP4 fuel pump on this engine is a known failure point that should be addressed.
Highly recommended years
- 2006–2007 (LBZ engine):
- Pros: Considered one of the best Duramax engines for its reliability, power, and simpler emissions controls. The engines have stronger internal components and are less regulated than later models.
- Cons: It's an older model, so it will lack modern features and has a simpler interior.
- 2017–2023 (L5P engine):
- Pros: More modern and powerful with higher horsepower and torque figures. This generation also includes modern features like available driver-assist technology.
- Cons: More expensive to maintain due to complex emissions equipment and a high-pressure fuel system.
Also a great choice
- 2011–2016 (LML engine):
- Pros: Powerful engine with updated towing and payload capacities. This generation is a strong performer, with good power output and a robust Allison transmission.
- Cons: Has a known issue with the CP4 fuel pump, which is recommended to be upgraded to prevent failure.
Years to approach with caution
- 2011–2016 (LML engine): While the LML engine is powerful, the CP4 fuel pump is a significant potential failure point that should be addressed with an upgrade.
- 2004.5–2005 (LLY engine): These models have a higher risk of overheating, so maintaining proper airflow and coolant levels is crucial.
Things to consider when buying
- Emissions control systems: Older models (pre-2007) have simpler emissions systems, making them easier and cheaper to maintain. Newer models are more complex and costly to repair.
- Transmission: The ZF6 manual transmission is difficult to find and expensive to repair, so you may want to stick to the automatic transmissions.
- Rust: If you live in a region with heavy road salt use, consider buying a southern-sourced truck to avoid rust issues.
How many miles per gallon does a GMC 3500HD get?
How Do GMC MPG Ratings Compare Across the Truck Lineup?
| Truck Model | Typical MPG Range (City/Highway) |
|---|---|
| Canyon 4WD | 17 / 21 |
| Sierra 1500 Diesel 2WD | 23 / 29 |
| Sierra 1500 Gas 2WD | 16 / 21 |
| Sierra 2500 / 3500 HD | 14–18 Highway (real-world) |
