After researching manufacturer specifications, industry safety standards, and aggregated owner feedback, we compared the leading in-bed auxiliary fuel tanks to help you choose the right one. These tanks let you carry extra diesel or gasoline for long hauls, equipment refueling, or backup supply. We evaluated each model on construction, fit, ease of installation, and real-world durability. Below are our findings, with honest pros, cons, and who should skip each pick.
| Photo | Product | Score | Buy |
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Transfer Flow 50 Gallon In-Bed Fuel Tank Best Overall 50-gallon capacity, aluminum construction, includes sending unit and fuel cap |
9.0 | 🛒 Check Price |
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RDS Manufacturing 50 Gallon Aluminum In-Bed Fuel Tank Best Value 50-gallon capacity, aluminum, includes 12V pump and nozzle |
8.6 | 🛒 Check Price |
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Titan Fuel Tanks 55 Gallon In-Bed Diesel Tank Largest Capacity 55-gallon capacity, steel, includes sending unit and vented cap |
8.4 | 🛒 Check Price |
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Aero 45 Gallon In-Bed Fuel Tank Slim Profile 45-gallon capacity, aluminum, low-profile design |
8.1 | 🛒 Check Price |
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Westech 40 Gallon In-Bed Diesel Tank Compact Choice 40-gallon capacity, steel, includes 12V pump |
7.8 | 🛒 Check Price |
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Dee Zee 35 Gallon In-Bed Fuel Tank Entry Level 35-gallon capacity, steel, includes lockable cap |
7.5 | 🛒 Check Price |
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Northern Tool + Equipment 30 Gallon In-Bed Fuel Tank Economy Pick 30-gallon capacity, steel, no pump |
7.2 | 🛒 Check Price |
1. Transfer Flow 50 Gallon In-Bed Fuel Tank: Best Overall
The Transfer Flow 50 gallon tank is a top choice for those who need a reliable, long-term fuel solution. Its aluminum construction resists rust and is lighter than steel, which helps maintain payload capacity. Based on owner feedback, the tank installs cleanly and the included sending unit simplifies wiring. The integrated rollover vent valve meets industry safety standards.
However, the cost is significantly higher than many steel alternatives, so budget-minded buyers may want to consider other options. Also, the 50-gallon size may be overkill for those who only need occasional range extension. This tank is best for frequent long-haul drivers or those who regularly refuel equipment on site.
- Aluminum tank with baffles reduces fuel slosh and improves stability.
- Includes a sending unit compatible with most aftermarket fuel gauges.
- Designed to fit full-size trucks with standard 8-foot beds.
Pros: High build quality and corrosion resistance.; Integrated safety features like rollover vent valve.
Cons: Premium price point compared to steel tanks.
2. RDS Manufacturing 50 Gallon Aluminum In-Bed Fuel Tank: Best Value
The RDS 50 gallon aluminum tank offers a great balance of features and cost. It comes equipped with a 12V pump and automatic nozzle, making it ready to use out of the box. The aluminum body resists rust, and the recessed fill neck helps keep the tank low profile. We found that the DOT approval adds confidence for highway use.
On the downside, the included pump has received mixed reviews for longevity, with some users needing to replace it within a year. The tank also lacks internal baffles, so fuel slosh can be noticeable. This is a solid choice for those who want a complete kit without overspending, but serious off-roaders or heavy users might prefer a more robust pump.
- Aluminum tank with a 12V pump and automatic nozzle for easy dispensing.
- DOT approved and includes a locking fuel cap.
- Recessed fill neck to reduce height profile.
Pros: Comes with a pump and nozzle, saving additional cost.; Good corrosion resistance for the price.
Cons: Some owners report the pump is not the most durable.
3. Titan Fuel Tanks 55 Gallon In-Bed Diesel Tank: Largest Capacity
The Titan 55 gallon tank is for those who need the absolute maximum fuel capacity. The steel construction is rugged and the powder coat finish resists chips and corrosion. It includes a sending unit and vented cap, making installation straightforward. Owner feedback highlights that it fits well in long-bed trucks and provides excellent range.
However, the tank is heavy, and when full it adds over 400 pounds, which can exceed payload limits on some half-ton trucks. Also, steel can rust if the coating is scratched. This tank is best for heavy-duty trucks and operators who prioritize range over weight savings. Those with lighter trucks should check payload capacity first.
- Steel tank with a durable powder coat finish.
- Includes a sending unit and vented fuel cap.
- Designed for long-bed trucks, with optional tunnel for short beds.
Pros: Highest capacity in our lineup for maximum range.; Steel construction is tough and impact resistant.
Cons: Heavy when full, reducing payload significantly.
4. Aero 45 Gallon In-Bed Fuel Tank: Slim Profile
The Aero 45 gallon tank is designed for those who want extra fuel without sacrificing rear visibility. The low-profile shape allows it to sit below the bed rails, and the aluminum build keeps weight manageable. Internal baffles help control fuel movement, improving handling. Based on owner feedback, it fits well in both short and long beds.
The trade-off is a smaller capacity of 45 gallons, which may not be enough for extreme long-haul needs. Some users also noted that the included fuel cap is not lockable, requiring an aftermarket upgrade. This tank is ideal for truck owners who want a discreet fuel solution for occasional trips or light commercial use.
- Low-profile design sits below bed rails for better visibility.
- Aluminum construction with internal baffles.
- Compatible with most full-size trucks, including short beds.
Pros: Slim design does not block rear window visibility.; Baffles reduce fuel slosh.
Cons: Smaller capacity than many competitors.
5. Westech 40 Gallon In-Bed Diesel Tank: Compact Choice
The Westech 40 gallon tank is a compact option for those who need auxiliary fuel but want to preserve bed space. The steel construction is durable, and the included pump and hose make it ready to use. It fits easily in short beds and leaves room for tools or other gear. Owner reviews note that the pump works well for occasional use.
However, the lack of internal baffles means fuel slosh is more pronounced, which can affect handling on rough roads. The 40-gallon capacity is on the smaller side, so it may not suit those needing maximum range. This tank is best for light-duty use or as a backup fuel source for equipment.
- Steel tank with a black powder coat finish.
- Includes a 12V pump and 12-foot hose.
- Compact size fits most truck beds, even short beds.
Pros: Small footprint leaves room for other cargo.; Pump included for easy dispensing.
Cons: No baffles, fuel slosh can be noticeable.
6. Dee Zee 35 Gallon In-Bed Fuel Tank: Entry Level
The Dee Zee 35 gallon tank is an economical choice for those who need a modest amount of extra fuel. The steel construction is basic but functional, and the lockable cap is a nice security feature. It fits most truck beds with minimal modification. Owner feedback suggests it works well for occasional use, such as refueling a boat or ATV.
The main drawbacks are the small 35-gallon capacity and the lack of an included pump, which adds to the total cost. The tank also lacks baffles, so slosh can be an issue. This tank is best for budget-conscious buyers who only need a small fuel reserve and don’t mind buying a pump separately.
- Steel tank with a durable black finish.
- Lockable fuel cap for security.
- Designed for universal fit in most truck beds.
Pros: Affordable entry-level option.; Lockable cap adds peace of mind.
Cons: Small capacity limits range extension.; No pump included, must purchase separately.
7. Northern Tool + Equipment 30 Gallon In-Bed Fuel Tank: Economy Pick
The Northern Tool 30 gallon tank is the most basic and affordable option. It is a simple steel tank with a vented cap, no pump, no sending unit, and no baffles. It is lightweight and easy to install, but you will need to purchase additional components to make it functional. Owner reviews indicate it works as a simple fuel storage tank but lacks refinement.
The major limitations are the small 30-gallon capacity and the absence of any features. Fuel slosh is significant, and the steel can rust if the paint is damaged. This tank is only suitable for those on a tight budget who need a basic fuel container for occasional use and are willing to add their own pump and gauge.
- Steel tank with a red powder coat finish.
- Simple design with a vented cap.
- Lightweight and easy to handle when empty.
Pros: Lowest price option.; Lightweight and easy to install.
Cons: No pump, no sending unit, basic features.; Small capacity and no baffles.
Frequently Asked Questions
Are in-bed auxiliary fuel tanks legal for highway use?
Yes, most reputable brands design their tanks to meet DOT (Department of Transportation) standards for highway use. However, regulations vary by state, especially regarding venting and spill containment. Always check local laws before installing. Tanks with DOT approval, like the Transfer Flow and RDS models, are generally safe for on-road use.
Can I use an in-bed fuel tank for gasoline or only diesel?
Many tanks are designed for diesel only, especially those with aluminum construction. Gasoline requires special venting and safety certifications due to its higher volatility. Some steel tanks can be used for gasoline if they are specifically rated for it, but always verify the manufacturer’s specifications. Using a diesel tank for gasoline can be dangerous.
How do I install an in-bed fuel tank?
Installation typically involves mounting the tank to the truck bed using bolts or straps, connecting the fuel line to the vehicle’s fuel system (if desired), and wiring any pump or sending unit. Most tanks come with instructions. Professional installation is recommended if you are not comfortable with basic mechanical work, especially for diesel tanks that may require tapping into the fuel system.
Do in-bed fuel tanks affect truck payload and handling?
Yes, a full 50-gallon tank adds about 400 pounds, which can reduce payload capacity and affect handling, especially on lighter trucks. It is important to check your truck’s payload rating and not exceed it. The added weight over the rear axle can improve traction but may also increase stopping distances. Consider air bags or upgraded suspension if you frequently carry a full tank.
What safety features should I look for in an auxiliary fuel tank?
Look for tanks with internal baffles to reduce fuel slosh, rollover vent valves to prevent spillage, and lockable caps for security. DOT or CARB (California Air Resources Board) approval indicates compliance with safety standards. Aluminum tanks resist rust better than steel, and a durable powder coat finish protects against corrosion. Avoid tanks without proper venting or those made of thin metal.
Our Verdict
After comparing specifications, safety certifications, and owner feedback, our top pick is the Transfer Flow 50 Gallon In-Bed Fuel Tank for its superior aluminum build, integrated safety features, and reliable performance. For those seeking the best value, the RDS Manufacturing 50 Gallon Aluminum In-Bed Fuel Tank offers a complete package with pump and nozzle at a lower price point, though with some durability trade-offs. Choose based on your capacity needs, budget, and whether you prioritize weight savings or maximum range.
Last reviewed and spec-checked: May 28, 2026. We re-check our picks and listings periodically.
