Expanding your truck’s fuel capacity with an auxiliary or transfer tank can significantly increase range, reduce refueling stops, and provide fuel for equipment. In our evaluation, we researched and compared a wide range of diesel fuel tanks, examining manufacturer specifications, safety certifications, material quality, and aggregated owner feedback to identify the most reliable and effective options available.
Our goal is to provide an evidence-based guide, highlighting the strengths and limitations of each product. We have focused on critical factors such as material construction, capacity, installation complexity, and adherence to industry safety standards to help you make an informed decision for your specific needs.
| Photo | Product | Score | Buy |
|---|---|---|---|
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Transfer Flow TRAX 3 Auxiliary Fuel System Top Pick: Smartest Integration Computer-controlled fuel transfer, various capacities (e.g., 50-98 gallons) |
9.0 | 🛒 Check Price |
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Dee Zee DZ91750B Aluminum Transfer Tank Runner-Up: Reliable Capacity 75-gallon capacity, L-shaped, non-rusting Brite-Tread aluminum |
8.7 | 🛒 Check Price |
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Titan Fuel Tanks 5010050 Auxiliary Fuel Tank Best Polymer Tank 50-gallon capacity, cross-linked polymer construction, in-bed design |
8.4 | 🛒 Check Price |
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RDS Manufacturing 72743 Aluminum Auxiliary Fuel Tank Solid Performer 60-gallon capacity, rectangular, 0.125-inch thick aluminum |
8.1 | 🛒 Check Price |
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Weather Guard 350-3-02 Diesel Transfer Tank Most Rugged Steel 50-gallon capacity, 14-gauge steel, black powder coat finish |
7.8 | 🛒 Check Price |
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UWS TBS-63-A-LP-SL Aluminum Combo Transfer Tank Best Toolbox Combo 36-gallon fuel tank with integrated toolbox, aluminum construction |
7.5 | 🛒 Check Price |
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Roughneck Aluminum Transfer Tank Budget-Friendly Option 50-gallon capacity, aluminum construction, rectangular design |
7.2 | 🛒 Check Price |
1. Transfer Flow TRAX 3 Auxiliary Fuel System: Top Pick: Smartest Integration
In our evaluation, the Transfer Flow TRAX 3 system stands out for its advanced computer-controlled fuel transfer, which automatically maintains the main fuel tank level. This eliminates the need for manual pumping or monitoring, providing a truly integrated solution for extended range. The heavy-gauge aluminized steel construction and internal baffling contribute to its high durability and safe operation, even under demanding conditions, based on manufacturer specifications and reported owner satisfaction with longevity.
However, the sophisticated technology comes with a notable increase in installation complexity and overall cost. Owners report that while the system performs exceptionally once installed, the initial setup requires more time and potentially professional assistance due to the electrical and sensor connections. This system might be overkill, and a less complex, gravity-feed tank could be a more practical and economical choice for users who only need occasional fuel transfer or prefer a simpler setup without electronic integration.
- Automatic fuel transfer system monitors and maintains main tank level
- Constructed from 12-gauge aluminized steel for corrosion resistance
- Includes dash-mounted LCD for real-time fuel level monitoring
Pros: Seamless, hands-free fuel management with TRAX 3 system; Robust construction and internal baffling for stability; Offers significant range extension without manual intervention
Cons: Higher initial investment compared to gravity-feed systems; Installation can be more complex due to wiring and sensor integration
2. Dee Zee DZ91750B Aluminum Transfer Tank: Runner-Up: Reliable Capacity
The Dee Zee DZ91750B earned its high rating in our comparison due to its robust construction and practical design. Made from heavy-gauge Brite-Tread aluminum, it offers excellent corrosion resistance and a lighter weight compared to steel tanks, which is a significant advantage for payload. The 75-gallon capacity provides a substantial increase in fuel range, and its L-shaped profile is particularly effective at utilizing truck bed space, allowing for toolboxes or other cargo to be placed above the shorter end. Based on owner feedback, the fit and finish are generally good, and the tank proves reliable for its intended purpose.
A key limitation, however, is that this is strictly a transfer tank, meaning it does not include an integrated pump for fuel transfer. Users must purchase a separate 12V transfer pump, which adds to the overall cost and setup time. For those seeking an all-in-one solution with a built-in pump, this model will require additional investment and installation steps. While durable, the Brite-Tread finish, while aesthetically pleasing, is susceptible to minor scratches and dings with heavy use, which might be a concern for users prioritizing a pristine appearance over rugged utility.
- Constructed from heavy-gauge Brite-Tread aluminum for durability and corrosion resistance
- L-shaped design maximizes bed space while maintaining substantial capacity
- Features a lockable cap and a sturdy hold-down kit for secure mounting
Pros: Excellent balance of capacity and bed utility due to L-shape; Aluminum construction ensures longevity without rust concerns; Relatively straightforward installation for a transfer tank
Cons: Manual fuel transfer requires a separate pump (not included); Finish can show scratches over time with heavy use
3. Titan Fuel Tanks 5010050 Auxiliary Fuel Tank: Best Polymer Tank
Our research into the Titan Fuel Tanks 5010050 highlights its innovative use of military-grade, cross-linked polymer. This material offers distinct advantages, primarily being completely corrosion-proof and significantly lighter than comparable metal tanks, which directly benefits a truck’s payload capacity. The polymer construction also demonstrates superior resistance to dents and minor punctures, a common concern with aluminum tanks. Based on manufacturer specifications, it’s designed for a universal fit in most truck beds and includes a comprehensive installation kit, simplifying the setup process for many users.
However, the 50-gallon capacity, while substantial, may not meet the needs of all users, particularly those requiring maximum range for very long hauls or extensive equipment fueling. For heavy commercial use or extreme off-grid applications, a larger capacity might be necessary. Additionally, proper venting is critical for polymer tanks, and some owner feedback suggests that careful attention to the vent line installation is necessary to prevent potential issues with fuel flow or pressure buildup, requiring diligent adherence to the installation instructions.
- Constructed from high-density, military-grade cross-linked polymer
- Designed to be compatible with most short-bed and long-bed trucks
- Comes with a complete installation kit for a direct fit
Pros: Corrosion-proof and significantly lighter than metal tanks; Durable polymer resists dents and punctures better than aluminum; Includes essential components for installation and fuel transfer
Cons: Capacity might be insufficient for some long-haul applications; Requires careful venting setup to prevent issues
4. RDS Manufacturing 72743 Aluminum Auxiliary Fuel Tank: Solid Performer
The RDS Manufacturing 72743 tank is a straightforward, heavy-duty solution for increasing fuel capacity. Our analysis of its specifications confirms its construction from thick 0.125-inch aluminum, which ensures excellent durability and resistance to corrosion, essential for longevity in various climates. The rectangular design is simple to mount in a truck bed, and the inclusion of a sight gauge is a practical feature, allowing for quick visual checks of the fuel level without needing to open the tank. Owner feedback consistently points to its reliability as a basic, robust auxiliary tank.
However, similar to some other transfer tanks, the RDS 72743 does not come with a fuel transfer pump. This means an additional purchase and installation step are necessary to move fuel from the auxiliary tank to the main tank, increasing the total investment and complexity for a complete system. Furthermore, its traditional rectangular shape, while easy to mount, might not optimize bed space as efficiently as an L-shaped tank, potentially limiting the room available for other cargo or toolboxes. Users prioritizing maximum bed utility might find this design less flexible.
- Constructed from durable 0.125-inch thick aluminum for strength
- Rectangular design offers straightforward installation in truck beds
- Includes a built-in sight gauge for easy fuel level monitoring
Pros: Heavy-duty aluminum construction provides long-term reliability; Simple, no-frills design is effective and easy to integrate; Integrated sight gauge is a practical feature for monitoring fuel
Cons: No pump included, requiring separate purchase and installation; Rectangular shape can limit bed versatility compared to L-shaped designs
5. Weather Guard 350-3-02 Diesel Transfer Tank: Most Rugged Steel
In our comparative analysis, the Weather Guard 350-3-02 stands out for its uncompromising durability. Constructed from heavy-duty 14-gauge steel and finished with a robust ARMOR-TUF® powder coat, this tank is built to withstand extreme conditions and impacts, making it ideal for demanding work environments. Its material strength provides superior protection against punctures and damage compared to lighter aluminum options. Based on manufacturer claims and owner reports, the finish holds up well against harsh weather and daily abuse, maintaining its integrity over time.
However, the primary drawback of this steel construction is its substantial weight. This can significantly reduce a truck’s available payload capacity, which is a critical consideration for many users, especially those already hauling heavy equipment or materials. Additionally, while the 50-gallon capacity is adequate for many, its physical footprint for that capacity can be larger than some more compact aluminum or polymer tanks. For users who prioritize maximizing payload or require a higher fuel capacity within a smaller space, the weight and size of this steel tank might be a limiting factor, making lighter alternatives more suitable.
- Constructed from heavy-duty 14-gauge steel for extreme durability
- Features a durable black ARMOR-TUF® powder coat finish for corrosion resistance
- Designed to be compatible with Weather Guard Cross Box toolboxes
Pros: Exceptional strength and resistance to impact from steel construction; High-quality powder coat provides excellent weather protection; Integrates well with other Weather Guard storage solutions
Cons: Significantly heavier than aluminum or polymer tanks, impacting payload; Smaller capacity for its physical footprint compared to some alternatives
6. UWS TBS-63-A-LP-SL Aluminum Combo Transfer Tank: Best Toolbox Combo
The UWS TBS-63-A-LP-SL stands out in our comparison for its innovative combination of a fuel transfer tank and a secure toolbox. This design is highly efficient for truck owners who need both additional fuel capacity and organized storage but have limited bed space. The commercial-grade aluminum construction provides good durability and resistance to rust, while the low-profile design ensures that rear visibility is not significantly obstructed. Based on owner feedback, the integrated solution is a practical choice for light commercial use or recreational applications where space optimization is key.
However, the inherent compromise in a combo unit is its limited fuel capacity. At 36 gallons, it offers less range extension compared to dedicated transfer tanks, which often hold 50 gallons or more. This makes it less suitable for users requiring maximum fuel reserves for long-distance hauling or heavy equipment operation. Furthermore, while it provides storage, the toolbox area is naturally constrained by the integrated fuel tank, meaning it cannot hold as much as a standalone, full-sized toolbox. Users prioritizing either maximum fuel capacity or maximum storage space might find this combo unit to be a compromise that doesn’t fully meet their specific, singular need.
- Combines a 36-gallon fuel tank with a secure, low-profile toolbox
- Constructed from commercial-grade aluminum with a one-piece tub design
- Features a stainless steel paddle handle lock for security
Pros: Efficiently uses truck bed space by combining storage and fuel; Aluminum construction offers good durability and corrosion resistance; Low-profile design allows for visibility out the rear window
Cons: Limited fuel capacity compared to dedicated transfer tanks; Toolbox storage space is reduced by the integrated tank
7. Roughneck Aluminum Transfer Tank: Budget-Friendly Option
In our evaluation, the Roughneck Aluminum Transfer Tank presents itself as a functional and more budget-conscious option for truck owners needing additional diesel capacity. Its 50-gallon capacity is a respectable size for most applications, offering a good balance between extended range and manageable size. The 0.125-inch thick aluminum construction provides adequate durability and corrosion resistance, which is a key advantage over steel tanks in terms of weight and rust prevention. Based on spec sheets, it includes standard features like a reinforced bung for a pump and a lockable cap, making it a viable entry-level choice.
However, compared to premium brands, the Roughneck tank’s material thickness, while adequate, is on the lower end, which could potentially impact its long-term resistance to heavy impacts or extreme abuse. Owner feedback occasionally points to the fit and finish being less refined than more expensive alternatives, with some minor imperfections reported. For users who prioritize maximum ruggedness, a flawless aesthetic, or who operate in extremely harsh environments, investing in a tank with thicker gauge aluminum or steel construction from a higher-tier brand might offer greater peace of mind and longevity. This tank is best suited for those with lighter-duty needs or a tighter budget.
- Constructed from 0.125-inch thick aluminum for adequate durability
- Features a rectangular design for simple placement in truck beds
- Includes a reinforced bung for pump installation and a lockable cap
Pros: Offers a practical 50-gallon capacity for extended range; Aluminum construction resists corrosion and keeps weight manageable; Straightforward design is easy to install and operate
Cons: Material thickness is on the lower end compared to premium options; Fit and finish may not be as refined as higher-priced competitors
Frequently Asked Questions
What is the difference between an auxiliary and a transfer fuel tank?
An auxiliary fuel tank is typically plumbed directly into the truck’s main fuel system, automatically supplying fuel to extend the vehicle’s range. A transfer tank, on the other hand, is designed to hold fuel for transfer to other vehicles or equipment, or to manually refill the truck’s main tank. Transfer tanks often require a separate pump to move fuel, while auxiliary systems integrate more seamlessly with the truck’s existing fuel lines.
What materials are commonly used for truck diesel fuel tanks?
Truck diesel fuel tanks are most commonly constructed from aluminum, steel, or high-density cross-linked polymer. Aluminum tanks are popular for their lighter weight and excellent corrosion resistance. Steel tanks offer superior strength and impact resistance but are heavier and susceptible to rust if not properly coated. Polymer tanks are corrosion-proof, lightweight, and resistant to dents, offering a good balance of properties.
Are auxiliary fuel tanks legal in all states?
The legality of auxiliary and transfer fuel tanks varies by state and depends on factors such as capacity, how the tank is mounted, and whether it’s connected to the vehicle’s primary fuel system. It is crucial to research and comply with all federal, state, and local regulations, including Department of Transportation (DOT) and National Fire Protection Association (NFPA) standards, before purchasing and installing any auxiliary fuel system. Always ensure proper venting and securing to meet safety requirements.
Do I need a special pump for a diesel transfer tank?
Yes, most transfer-only diesel fuel tanks do not come with an integrated pump. You will typically need to purchase a separate 12-volt electric fuel transfer pump designed for diesel fuel. These pumps are essential for safely and efficiently moving fuel from the transfer tank to your truck’s main tank or other equipment. Ensure the pump you select is rated for diesel and has appropriate flow rates for your needs.
How do I ensure my auxiliary fuel tank is safely installed?
Safe installation of an auxiliary fuel tank requires strict adherence to the manufacturer’s instructions and all applicable safety standards. Key considerations include securely mounting the tank to prevent movement, ensuring proper venting to prevent pressure buildup, using appropriate fuel lines and fittings that are rated for diesel, and correctly wiring any electrical components if it’s an auxiliary system. Professional installation is recommended if you are not experienced with fuel system modifications.
Our Verdict
Based on our comprehensive research and comparison, the Transfer Flow TRAX 3 Auxiliary Fuel System is our Top Pick for its advanced, seamless integration and automated fuel management. For a highly reliable and durable option with excellent capacity and space utilization, the Dee Zee DZ91750B Aluminum Transfer Tank stands out as our Runner-Up, offering a strong balance of performance and value for many truck owners.
