Adding an auxiliary fuel tank to your truck extends your range and reduces fuel stops, especially for long hauls or off-grid work. We researched and compared seven top-rated models based on manufacturer specifications, safety standards, and aggregated owner feedback. Our evaluation covers material quality, capacity, ease of installation, and long-term durability. Whether you need a simple gravity-fed tank or a fully integrated transfer system, this guide helps you choose wisely.
| Photo | Product | Score | Buy |
|---|---|---|---|
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Transfer Flow 50 Gallon Replacement Fuel Tank Best Overall Capacity 50 gallons, 14-gauge steel, fits long bed trucks |
9.1 | 🛒 Check Price |
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RDS Manufacturing 30 Gallon Diesel Transfer Tank Best Value Transfer Tank 30 gallons, 16-gauge steel, includes 12V pump |
8.7 | 🛒 Check Price |
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Titan Fuel Tanks 36 Gallon Auxiliary Fuel Tank Best Fit for Ford Super Duty 36 gallons, rotomolded polyethylene, vehicle-specific fit |
9.0 | 🛒 Check Price |
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Scepter Military Fuel Can 5 Gallon (Set of 2) Best Portable Option 5 gallons each, HDPE plastic, military-grade |
8.3 | 🛒 Check Price |
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Dee Zee DZ8750 50 Gallon Aluminum Transfer Tank Best Lightweight Aluminum 50 gallons, aluminum, includes 12V pump and meter |
8.5 | 🛒 Check Price |
|
Northern Tool 30 Gallon Diesel Fuel Tank Budget Pick 30 gallons, 16-gauge steel, manual pump included |
7.8 | 🛒 Check Price |
 |
Better Built 40 Gallon Rectangular Fuel Tank Best for Space Efficiency 40 gallons, 16-gauge steel, rectangular shape |
8.1 | 🛒 Check Price |
1. Transfer Flow 50 Gallon Replacement Fuel Tank: Best Overall Capacity
The Transfer Flow 50 Gallon Replacement Fuel Tank is the top pick for truck owners who want maximum fuel capacity without sacrificing bed space. In our evaluation, its 14-gauge steel construction and internal baffles meet or exceed OEM safety standards. Owner feedback consistently praises the straightforward installation on compatible long-bed trucks, though the tank’s weight when full can reduce payload. We compared its build quality to other brands and found it superior in weld integrity and coating durability.
However, this tank is not ideal for those with short-bed trucks or who need a quick temporary solution. The replacement design requires removing the factory tank, which may be a project for some. Also, the cost is higher than many add-on tanks, making it a long-term investment. If you’re not ready for a permanent modification, consider a portable auxiliary tank instead.
- Replaces factory tank for seamless integration and full bed use
- Made in USA with 14-gauge steel and internal baffles for safety
- Includes sender unit and fuel tank cap; no drilling required
Pros: Massive capacity without losing bed space; High-quality construction with excellent corrosion resistance
Cons: Heavy when full, may affect payload capacity
2. RDS Manufacturing 30 Gallon Diesel Transfer Tank: Best Value Transfer Tank
The RDS Manufacturing 30 Gallon Diesel Transfer Tank offers excellent value for truck owners who need a simple, self-contained fueling solution. Our research shows that its 16-gauge steel and powder coating hold up well in typical conditions, though some owners reported minor rust after years of exposure. The included 12V pump is convenient, but we found the flow rate adequate for occasional use rather than heavy-duty refueling. Compared to similar-priced tanks, this model has better overall build quality.
This tank works best for those who want an easy, bolt-in solution for a pickup bed. However, the 30-gallon capacity may be too small for long-distance overlanding or commercial use. Additionally, the pump’s plastic components could be a weak point over time. If you need a higher-capacity or more rugged system, consider spending more on a premium unit.
- Skid-mount design with built-in 12V pump for easy fueling
- Powder-coated finish for corrosion resistance
- Comes with hose, nozzle, and mounting hardware
Pros: Affordable price with pump included; Sturdy steel construction with good rust protection
Cons: Pump flow rate is moderate; not for high-volume needs
3. Titan Fuel Tanks 36 Gallon Auxiliary Fuel Tank: Best Fit for Ford Super Duty
The Titan Fuel Tanks 36 Gallon Auxiliary Tank is our top pick for Ford Super Duty owners seeking a seamless auxiliary fuel solution. In our evaluation, the rotomolded polyethylene design offers excellent impact resistance and avoids the rust issues of steel tanks. Owner feedback highlights the precise fit and straightforward installation, though it requires removing the spare tire. We compared its capacity and integration to other brands and found Titan’s engineering to be superior for this application.
This tank is not suitable for owners of other truck brands, and its plastic construction may not appeal to those preferring steel. The 36-gallon capacity is moderate, so those needing more than 50 gallons should look elsewhere. Additionally, the spare tire relocation may be a drawback for some. If you own a Ford Super Duty and want a hassle-free auxiliary tank, this is an excellent choice.
- Custom-molded to fit Ford Super Duty trucks without bed loss
- UV-stabilized polyethylene resists corrosion and dents
- Includes all necessary hardware and detailed instructions
Pros: Perfect fit for Ford Super Duty; no modifications needed; Lightweight and durable plastic construction
Cons: Only compatible with specific Ford models
4. Scepter Military Fuel Can 5 Gallon (Set of 2): Best Portable Option
The Scepter Military Fuel Can is the best portable auxiliary fuel solution for truck owners who need flexibility. Our research shows these cans meet strict military specifications for durability and safety. Owner feedback consistently praises the leak-proof design and robust construction, though the spout can be slow. We compared them to civilian cans and found superior build quality and longevity. They are ideal for emergency backup or short trips where permanent tanks are unnecessary.
However, these cans are not a substitute for a large auxiliary tank. If you need to extend your range significantly, you would need several cans, which take up bed space and require manual handling. Also, the 5-gallon size means more frequent refueling stops. For those who want a simple, no-installation solution for occasional use, these are excellent. For long-haul needs, consider a larger mounted tank.
- NATO-style design with self-venting spout for safe pouring
- Made in USA from high-density polyethylene
- Stackable and portable; no installation required
Pros: Extremely durable and leak-proof; Portable and versatile for multiple vehicles
Cons: Small capacity per can; requires multiple cans for significant range
5. Dee Zee DZ8750 50 Gallon Aluminum Transfer Tank: Best Lightweight Aluminum
The Dee Zee DZ8750 50 Gallon Aluminum Transfer Tank is a great choice for those who prioritize weight savings and corrosion resistance. Our evaluation of its aluminum construction shows it is significantly lighter than steel tanks, which helps preserve payload capacity. Owner feedback notes the digital meter is accurate and the pump works well, though some reported the pump could be faster. We compared it to steel tanks of similar capacity and found the aluminum’s durability acceptable, though it dents more easily.
This tank is best for truck owners who frequently carry heavy loads and need to minimize added weight. However, the aluminum is less impact-resistant than steel, so it may not be ideal for off-road or rough use. Additionally, the price is higher than comparable steel tanks. If you don’t need the weight savings, a steel tank might offer better value and toughness.
- Lightweight aluminum construction reduces added weight
- Built-in 12V pump with digital fuel meter for accurate dispensing
- Skid-mount design with forklift pockets for easy handling
Pros: Aluminum won't rust, lighter than steel; Digital meter helps track fuel usage
Cons: Aluminum is prone to denting if not handled carefully
6. Northern Tool 30 Gallon Diesel Fuel Tank: Budget Pick
The Northern Tool 30 Gallon Diesel Fuel Tank is the budget-friendly option for truck owners who need a basic auxiliary tank without breaking the bank. Our research shows it offers decent value for the price, but the 16-gauge steel and powder coating are not as durable as higher-end models. Owner feedback indicates the manual pump works but is slow, and some reported rust after a few years in humid climates. We compared it to the RDS tank and found the RDS offers better build quality for a slightly higher price.
This tank is suitable for occasional use or for those on a tight budget. However, if you plan to use it frequently or in harsh conditions, investing in a better-coated or stainless tank is wise. The manual pump can be a workout, and the lack of a pump means you need to use a separate transfer system. For serious users, we recommend stepping up to a model with a 12V pump.
- Economical choice with manual rotary pump
- Skid-mount design for bed installation
- Powder-coated finish for basic protection
Pros: Lowest cost option for a transfer tank; Simple design with no electrical components
Cons: Manual pump is slow and labor-intensive; Paint may chip over time; less durable than premium tanks
7. Better Built 40 Gallon Rectangular Fuel Tank: Best for Space Efficiency
The Better Built 40 Gallon Rectangular Fuel Tank is designed for truck owners who want to maximize usable bed space. Our evaluation of its shape shows it fits neatly against the cab, leaving more room for cargo. Owner feedback is mixed: many appreciate the space-saving design, but some have reported weld failures or leaks after a few years. We compared its construction to the Transfer Flow tank and found the Better Built uses thinner steel, which impacts long-term durability.
This tank is a good choice if space efficiency is your top priority and you are willing to accept some trade-offs in build quality. However, for heavy-duty or off-road use, we recommend a tank with thicker steel and better welds. Also, the 40-gallon capacity may not be enough for extreme long-haul needs. If you require a tank that will last many years without issues, consider a premium option.
- Rectangular design maximizes bed space usage
- Low-profile for better visibility out the rear window
- Includes mounting brackets and hardware
Pros: Space-efficient shape fits well in truck beds; Low profile improves rear visibility
Cons: Some owners report weld quality issues; Not as durable as thicker-gauge tanks
Frequently Asked Questions
Are auxiliary fuel tanks safe to install in a truck bed?
Yes, when installed properly and certified to DOT standards, auxiliary tanks are safe. Our research shows that tanks with internal baffles, secure mounting, and proper venting minimize risks. Always follow the manufacturer’s instructions and check local regulations.
Can I use an auxiliary tank for gasoline instead of diesel?
Most auxiliary tanks are designed specifically for diesel or gasoline. Check the product specifications: diesel tanks often have different fittings and materials. Using a diesel tank for gasoline may cause compatibility issues with seals and pumps. We recommend using tanks intended for your fuel type.
How do I install an auxiliary fuel tank in my truck?
Installation varies by tank type. Replacement tanks require removing the factory tank, while skid-mount tanks bolt into the bed. Many tanks come with hardware and instructions. Some owners opt for professional installation to ensure safety and compliance with local codes.
Will an auxiliary tank affect my truck's warranty?
Aftermarket modifications can potentially void parts of your warranty if they cause damage. However, many auxiliary tanks are designed as bolt-on upgrades that do not alter the vehicle’s fuel system permanently. Check with your dealer and keep records of professional installation.
How do I calculate the range increase from an auxiliary tank?
Multiply the auxiliary tank’s capacity (in gallons) by your truck’s average fuel economy (mpg). For example, a 30-gallon tank with 15 mpg adds 450 miles of range. Remember that carrying extra weight reduces fuel economy slightly.
Our Verdict
Our top pick is the Transfer Flow 50 Gallon Replacement Fuel Tank for its superior build quality and seamless integration. For a balance of value and features, the RDS Manufacturing 30 Gallon Diesel Transfer Tank is an excellent runner-up.
