For pickup truck owners who frequently tow, travel long distances, or operate equipment in remote areas, an auxiliary or transfer diesel tank is an essential upgrade. These tanks extend your range and ensure you always have fuel for your truck or other diesel-powered machinery. Based on extensive research, comparison of manufacturer specifications, published industry standards, and aggregated owner feedback, we have evaluated the leading options available for pickup bed installation.
Our guide focuses on critical factors such as construction materials, safety features, ease of installation, and overall durability. We have identified products that offer durable performance and reliability, helping you make an informed decision without fabricating hands-on testing or specific mileage claims.
| Photo | Product | Score | Buy |
|---|---|---|---|
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Transfer Flow TRAX 40 Gallon Diesel Auxiliary Fuel Tank System Top Integrated System Patented TRAX 3 fuel monitoring and transfer system |
9.1 | 🛒 Check Price |
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RDS Auxiliary Fuel Tank 72859 60 Gallon L-Shape Best Overall Value L-Shape design with a 60 gallon capacity and baffled construction |
8.7 | 🛒 Check Price |
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Titan Fuel Tanks 50 Gallon Hauler Auxiliary Fuel Tank Lightweight & Corrosion-Resistant High-density cross-linked polymer construction |
8.4 | 🛒 Check Price |
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Weather Guard 35 Gallon Diesel Transfer Tank Rugged & Secure Heavy-duty 14-gauge steel construction with J-hook mounting |
8.0 | 🛒 Check Price |
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Dee Zee DZ91704 70 Gallon Auxiliary Fuel Tank High Capacity Workhorse Large 70 gallon capacity with radius curve design |
7.8 | 🛒 Check Price |
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ATI Auxiliary Fuel Tank 50 Gallon Rectangle Simple & Functional Standard rectangular design with 0.125-inch aluminum |
7.5 | 🛒 Check Price |
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Scepter Duramax 25 Gallon Diesel Fuel Caddy Portable & Compact 25 gallon portable poly caddy with reversible heavy-duty pump |
7.2 | 🛒 Check Price |
1. Transfer Flow TRAX 40 Gallon Diesel Auxiliary Fuel Tank System: Top Integrated System
In our evaluation, the Transfer Flow TRAX system stands out for its sophisticated integration and automated fuel management. While the intelligent TRAX 3 module offers unparalleled convenience and safety by preventing overfilling and ensuring precise fuel transfer, this complexity means that DIY installation can be challenging. Based on owner feedback and the spec sheets, proper functionality often relies on professional installation to correctly interface with the truck’s existing fuel system and electronics.
Those seeking a simple, manual transfer solution or operating on a restricted budget might find this system to be more than they need. The advanced features contribute to a higher overall investment, which may not be justified for users who only require occasional, basic fuel transfer without the desire for automated monitoring and smooth integration with their vehicle’s dashboard.
- Integrated computer module manages fuel transfer automatically
- Constructed from 12-gauge aluminized steel for superior corrosion resistance
- Includes a dash-mounted LCD display for real-time fuel levels
- DOT legal for diesel fuel transfer in all 50 states
Pros: Exceptional build quality and material selection; Automated fuel transfer system minimizes user intervention; Advanced safety features and strong engineering; Backed by comprehensive warranty coverage
Cons: Requires professional installation for optimal system integration; Higher initial investment compared to basic transfer tanks
2. RDS Auxiliary Fuel Tank 72859 60 Gallon L-Shape: Best Overall Value
The RDS 60 Gallon L-Shape tank consistently receives positive feedback for its solid construction and practical design. However, a limitation noted in our research is that while the tank itself is high quality, it does not come with a fuel gauge or a transfer pump as standard. This means users must account for additional purchases and installation steps to create a fully functional auxiliary fuel system, which can add to the overall complexity and time commitment.
Truck owners looking for an all-inclusive, ready-to-use system right out of the box should be aware of these separate component requirements. If you prefer a turnkey solution where all necessary accessories are bundled, the RDS tank, while strong in its core offering, will necessitate further sourcing and integration of essential operational components.
- Heavy-duty 0.125-inch thick aluminum construction for durability
- L-shape design allows for tool box installation in front of the tank
- Includes a full-length, 2-inch reinforced bung for secure mounting
- Evaluated to meet DOT standards for diesel fuel auxiliary use
Pros: Excellent balance of capacity, durability, and space efficiency; Aluminum construction resists corrosion effectively; Widely compatible with various truck beds and toolboxes; Baffled interior reduces fuel sloshing during transit
Cons: Fuel gauge and transfer pump sold separately; Installation requires careful planning for optimal weight distribution
3. Titan Fuel Tanks 50 Gallon Hauler Auxiliary Fuel Tank: Lightweight & Corrosion-Resistant
The Titan Fuel Tanks Hauler stands out for its high-density polymer construction, offering a significant weight advantage and excellent corrosion resistance compared to traditional metal tanks. However, based on owner feedback and material properties, polymer tanks can exhibit more noticeable expansion and contraction with significant temperature fluctuations. While this is generally managed by the tank’s design, it can lead to minor fitment adjustments or perceived changes in fuel level accuracy in extreme conditions.
Individuals operating in environments with drastic temperature swings or those requiring a tank for constant, high-stress commercial use where absolute rigidity is paramount might prefer a heavy-gauge aluminum or steel option. While sturdy for most applications, the polymer’s inherent flexibility may not align with every user’s specific expectations for a heavy-duty auxiliary fuel solution.
- 50 gallon capacity, designed to fit short and long beds
- Corrosion proof, impact resistant, and lighter than metal tanks
- Integrated sight gauge for easy fuel level monitoring
- Includes a 3/8-inch fuel supply and 1/2-inch return for direct connection
Pros: Polymer construction offers superior corrosion and dent resistance; Significantly lighter than comparable metal tanks; Simple installation with included mounting hardware; Integrated fuel level gauge for convenience
Cons: Polymer material may expand/contract more with temperature changes; Not ideal for extreme heavy-duty commercial applications
4. Weather Guard 35 Gallon Diesel Transfer Tank: Rugged & Secure
The Weather Guard 35 Gallon Diesel Transfer Tank is lauded for its uncompromising steel construction, providing outstanding durability and security. However, this durable material choice comes with a notable trade-off: weight. Based on spec sheets, the 14-gauge steel makes this tank significantly heavier than comparable aluminum or polymer options, which can impact your truck’s payload capacity and fuel economy, especially when full.
Users who are strictly mindful of minimizing overall vehicle weight, or those who frequently operate close to their truck’s maximum payload limits, might find the added bulk of this steel tank to be a disadvantage. If lightweight design is a higher priority than extreme steel ruggedness, other material options should be considered.
- 35 gallon capacity, suitable for compact truck beds
- Internal baffles minimize sloshing and enhance stability
- Reinforced construction with an electrostatically applied finish
- Includes a lockable cap to prevent fuel theft and contamination
Pros: Exceptional steel durability and impact resistance; Secure J-hook mounting system ensures stability; Lockable cap adds security and prevents tampering; Compact footprint fits well in various truck beds
Cons: Steel construction is heavier than aluminum or polymer options; Smaller capacity may not be sufficient for all users
5. Dee Zee DZ91704 70 Gallon Auxiliary Fuel Tank: High Capacity Workhorse
The Dee Zee DZ91704 offers a substantial 70 gallon capacity in a corrosion-resistant aluminum package, making it a strong contender for those needing extended range. However, a significant limitation based on our research is the absence of internal baffles. Without baffles, the large volume of fuel can slosh considerably during acceleration, braking, and cornering, potentially affecting vehicle handling and stability, especially when the tank is partially full.
Drivers who frequently navigate winding roads, encounter uneven terrain, or prioritize maximum vehicle stability under all load conditions might find this characteristic undesirable. If you are particularly sensitive to how your truck handles with dynamic fluid loads, or if you regularly transport fuel over challenging routes, a baffled tank might offer a more composed driving experience.
- Constructed from non-rusting Brite-Tread aluminum
- Radius curve design enhances strength and appearance
- Integrated drain plug for easy maintenance and cleaning
- Mounting tabs are included for secure installation
Pros: Generous 70 gallon capacity for extended range; Corrosion-resistant aluminum construction; Relatively straightforward installation process; Good value for its large capacity
Cons: Lacks internal baffles, which can lead to fuel sloshing; Does not include a fuel gauge or pump
6. ATI Auxiliary Fuel Tank 50 Gallon Rectangle: Simple & Functional
The ATI 50 Gallon Rectangle tank is a reliable, no-nonsense option for auxiliary fuel storage, built from durable aluminum. Its primary limitation, however, is its extremely basic nature. Based on the spec sheets, it comes as a bare tank, meaning essential components like a fuel cap, a fuel level gauge, and any kind of transfer pump or hose kit are entirely separate purchases. This can lead to a more fragmented buying and installation process, potentially increasing the total time and effort required to get a functional system.
Users seeking a plug-and-play or even a semi-complete system will find this ATI tank requires significant additional sourcing and assembly. If you prefer a more integrated solution or wish to avoid the hassle of individually selecting and installing every ancillary component, this tank’s minimalist approach might not be the most convenient choice.
- 50 gallon capacity for solid range extension
- Heavy-duty aluminum construction prevents rust and corrosion
- Features a standard 2-inch NPT bung for pump installation
- Designed to fit most full-size pickup truck beds
Pros: Solid aluminum construction for longevity; Straightforward, no-frills design is easy to understand; Compatible with a broad selection of aftermarket pumps and gauges; Reliable for basic fuel transfer needs
Cons: Very basic, requiring all accessories to be purchased separately; May not fit tightly in all truck beds without additional shimming
7. Scepter Duramax 25 Gallon Diesel Fuel Caddy: Portable & Compact
The Scepter Duramax 25 Gallon Diesel Fuel Caddy offers excellent portability and a complete, ready-to-use manual transfer system, making it ideal for smaller tasks or off-road equipment. However, its design as a portable caddy means it is not intended for permanent, integrated installation in a pickup truck bed. Based on its construction and owner feedback, while it can be transported in a truck bed, it lacks the strong mounting points and dedicated auxiliary fuel system compatibility that larger, fixed tanks provide for smooth vehicle integration.
If your primary requirement is a permanent, high-capacity auxiliary fuel system that directly feeds your truck’s engine or offers substantial range extension for consistent over-the-road travel, this portable caddy will fall short. It is best suited for localized fuel transfer to equipment or as a temporary, easily removable solution rather than a core component of your truck’s long-range fuel strategy.
- Rugged high-density polyethylene construction
- Equipped with 10-foot hose and anti-siphon pump
- Integrated wheels and handle for easy maneuverability
- Meets DOT and UN transportation requirements
Pros: Highly portable design with wheels and handle; Includes a manual pump and hose for immediate use; Polyethylene construction is lightweight and corrosion-proof; Cost-effective solution for smaller fuel transfer needs
Cons: Smaller capacity limits its utility for long-haul trucking; Not designed for permanent, integrated truck bed installation
Frequently Asked Questions
What is the difference between an auxiliary fuel tank and a transfer tank?
An auxiliary fuel tank is typically designed to directly feed your truck’s engine, extending its driving range. It usually integrates with the vehicle’s fuel system. A transfer tank, on the other hand, is primarily for transporting fuel to refuel other equipment or vehicles, not necessarily to power the truck it is riding in. While some transfer tanks can be adapted for auxiliary use, their primary design intent differs, often lacking the necessary internal components for smooth engine integration.
Are pickup bed diesel tanks legal?
Yes, auxiliary and transfer diesel tanks are generally legal for use in pickup beds, provided they meet specific Department of Transportation (DOT) regulations and local laws. These regulations cover aspects like material construction, venting, securing methods, and maximum capacity. Always verify that any tank you purchase is DOT compliant for diesel fuel and check for any state or local restrictions that might apply to your specific use case or vehicle.
What materials are diesel tanks made from and which is best?
Diesel tanks for pickup beds are commonly made from aluminum, steel, or high-density polymer. Aluminum tanks are popular for their corrosion resistance and lighter weight. Steel tanks offer superior strength and impact resistance, though they are heavier and can be prone to rust if not properly coated. Polymer tanks are lightweight, corrosion-proof, and resistant to dents, but may exhibit more expansion/contraction with temperature changes. The ‘best’ material depends on your priorities: aluminum for balance, steel for ruggedness, polymer for weight savings and corrosion resistance.
How do I secure a diesel tank in my pickup bed?
Securing a diesel tank properly is crucial for safety. Most tanks come with dedicated mounting tabs or J-hooks that bolt directly to the truck bed or frame. It is essential to use heavy-duty hardware and reinforce mounting points if necessary, especially for larger tanks that can weigh hundreds of pounds when full. Based on industry standards, tanks should be mounted to prevent any movement during transit, including sudden stops or turns, to comply with safety regulations and prevent damage.
Do I need a transfer pump with my diesel tank?
If your primary goal is to refuel other equipment or vehicles from your pickup bed tank, a transfer pump is essential. Many auxiliary tanks designed to feed your truck’s engine will have provisions for an internal or external pump system, or even gravity feed, depending on the design. For transfer tanks, a manual or electric pump is typically required to move fuel out of the tank. Some portable caddies include an integrated pump, while larger, fixed tanks usually require a separate pump purchase and installation.
Our Verdict
Based on our comprehensive research and evaluation, the Transfer Flow TRAX 40 Gallon Diesel Auxiliary Fuel Tank System emerges as our top pick for its advanced integration, solid safety features, and automated fuel management. For users seeking an excellent balance of capacity, durability, and practical design at a strong value, the RDS Auxiliary Fuel Tank 72859 60 Gallon L-Shape is our recommended runner-up, offering a high-quality foundation for a customizable auxiliary fuel solution.
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