How many MPG does a 2004 Dodge Ram 2500 diesel get?

The 2004 Dodge Ram 2500 diesel, powered by a 5.9-liter Cummins turbo-diesel inline-six, typically achieves about 15 miles per gallon combined in mixed driving, with roughly 12–14 mpg in city conditions and 17–20 mpg on the highway; actual numbers vary based on drivetrain, payload, and driving style. This article reviews the expected mpg ranges across common configurations, explains why they vary, and provides tips for improving efficiency.

EPA fuel economy by configuration

EPA estimates vary by drivetrain and transmission; the following figures reflect representative ratings for common 2004 Ram 2500 diesel configurations.

Two-wheel drive (2WD)

• 2WD with automatic transmission: City about 12–13 mpg, highway about 17–19 mpg, combined roughly 14–16 mpg.


• 2WD with manual transmission: City about 12–14 mpg, highway about 19–21 mpg, combined around 15–17 mpg.

Notes: Actual figures depend on gearing and year-to-year calibration; check the specific vehicle's EPA sticker for exact ratings.

Four-wheel drive (4WD)

• 4x4 with automatic transmission: City about 11–12 mpg, highway about 16–18 mpg, combined around 13–15 mpg.


• 4x4 with manual transmission: City about 12–13 mpg, highway about 18–19 mpg, combined around 15–17 mpg.

Keep in mind that 4WD configurations and the weight of a heavy payload typically reduce highway efficiency compared with 2WD.

Real-world mpg and factors

In practice, real-world fuel economy often runs below EPA estimates, especially when towing or carrying loads. Here are common ranges reported by owners and reviewers.

• Light daily driving with a 2WD diesel: 14–18 mpg combined


• Towing or hauling heavy loads: 11–15 mpg


• Highway cruising with steady speed and minimal wind: 17–22 mpg


• Urban, stop-and-go driving with frequent accelerations: 12–14 mpg

Real-world results vary greatly based on payload, terrain, altitude, and maintenance. Always consider your typical usage when estimating real-world mpg.

Tips to maximize mpg

Small changes can yield noticeable gains in fuel economy for a heavy diesel pickup. Here are practical steps to consider.

1. Keep tires inflated to the recommended pressure and ensure proper wheel alignment.


2. Follow a regular maintenance schedule: replace air and fuel filters, perform oil changes, and maintain the cooling and fuel systems.


3. Drive smoothly: moderate acceleration, gradual braking, and steady speeds; avoid excessive idling.


4. Limit payload and remove extraneous drag sources when possible, such as unused roof racks.


5. Use cruise control where appropriate and safe to maintain a steady pace on highways.


6. Choose fuel-efficient towing setups and consider weight-reducing modifications if needed.

Implementing these practices can help maximize efficiency without compromising performance.

Summary

The 2004 Ram 2500 diesel generally delivers mid-teens mpg in mixed use, with higher highway efficiency and lower city efficiency. Expect roughly 12–14 mpg in city driving and 17–20 mpg on highways for many common configurations, though payload, towing, terrain, and maintenance can significantly affect the actual numbers. For precise figures, refer to the exact configuration’s EPA label and mileage claims.

What is the fuel mileage on a 2004 5.9 Cummins?

The Cummins 5.9L engine clearly will get the job done. Without a tow load, it's averaging 25 miles per gallon on the highway!

What year to stay away from Ram 2500 diesel?

You should avoid the 2012-2016 and 2018 model years of the Ram 2500 due to known reliability issues. Other years to be cautious about include 2019-2023, which have had recalls for electrical issues and potential fire risks, and the 1999-2001 models if looking at a 5.9L Cummins, as some have a flawed "53 block" engine that can crack under stress. 
Years with significant reliability issues

• 2012-2016: These models are frequently cited for brake system failures, steering problems (like "death wobble"), turbocharger breakdowns, and transmission defects. 
• 2018: This year also has a reputation for chronic reliability issues, including faulty steering, turbocharger problems, and transmission defects. 
• 2019-2023: These models have had recalls for electrical shorts, fire risks, and intake heater grid relay problems. Some have also experienced transmission issues. 
• 1999-2001 (5.9L Cummins): Be cautious with these years because they may have a "53 block" engine, which is prone to cracking under stress, leading to coolant leaks and overheating. 

Other model years to consider with caution

• 2014-2015: Some models experienced engine knocking that could lead to failure. 
• 2003-2004: These years had recalls for airbag ruptures and problems with lift and water pumps. 

What is the gas mileage on a 2004 Dodge Ram 2500 diesel?

The 2004 Dodge Ram 2500 diesel with a 5.9L Cummins engine gets an average of around 17–18 mpg, with some drivers reporting up to 25 mpg on the highway under optimal conditions. City mileage is lower, typically around 15 mpg. Fuel efficiency depends heavily on driving style, vehicle maintenance, and driving conditions.
 
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Factors influencing MPG

• Driving style: Steady speeds and avoiding rapid acceleration/deceleration can significantly improve fuel economy. 
• Maintenance: Regular maintenance helps keep the engine running efficiently. 
• Towing: Towing or carrying heavy loads will decrease fuel economy. 
• Modifications: Aftermarket parts like cold air intakes or exhaust systems may have a minor impact, but can also affect the results. 

MPG estimates

• Highway: 17–25 mpg, depending on conditions and driving habits.
• City: Approximately 15 mpg.
• Combined: Around 17–18 mpg. 

Is the 2004 5.9 Cummins reliable?

The 2004 5.9L Cummins is a highly reliable engine, especially because it uses the more durable common-rail injection system with a CP3 pump instead of the older, less reliable VP44 pump. While generally bulletproof, common issues to watch for include potential cracking exhaust manifolds, front-end wear from heavy use or modifications, and potential weak spots in the electronics or cooling system. With proper maintenance and care, these engines can achieve very high mileage.
 
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Common issues and maintenance

• Exhaust manifold: The exhaust manifold is prone to cracking due to thermal expansion. Upgrading to a performance manifold can prevent this. 
• Front-end wear: Front-end components like the track bar, ball joints, and steering linkage can wear out, leading to issues like "death wobble". Regular inspection is necessary, especially on trucks with oversized tires or lift kits. 
• Fueling system: While more reliable than older systems, the fuel injectors and lift pump can still be a weak point. Upgrades like a FASS or AirDog system can help protect the lift pump and injectors. 
• Electronics: Some common issues with the truck's electronics include weak wiring for rear power windows and door locks, as well as potential gauge cluster problems. 
• Cooling system: The rearmost cylinders can run hotter than others. A coolant bypass kit can help improve coolant flow and prevent potential overheating of cylinder #6. 
• Transmission: Both automatic and manual transmissions can be weak points. Look for trucks that have had their transmissions upgraded with a heavy-duty clutch for manuals or a full rebuild kit for automatics. 
• Rust: Pay close attention to the truck's body for rust, particularly on the fenders, cab corners, and rocker panels, as the clear coat is also prone to peeling. 
• Engine oil: A Blackstone Oil Analysis can reveal any problems in the engine's internals, making it crucial for identifying potential issues before they become severe. 

Key strengths

• Legendary reliability: The 5.9L Cummins is famous for its durability and can last for hundreds of thousands of miles with proper maintenance. 
• Strong performance: It provides a great combination of power and torque, making it a capable workhorse for towing and hauling. 
• Simple mechanics: Unlike modern engines, the 5.9L is relatively simple, with fewer complex electronics to fail.