Auxiliary Fuel Tanks For Pickup Trucks: Expanding Your Horizons

Auxiliary Fuel Tanks For Pickup Trucks: Expanding Your Horizons pickup.truckstrend.com

For many pickup truck owners, the open road is an invitation to adventure, whether it’s towing a heavy trailer across states, venturing deep into remote wilderness, or simply needing reliable fuel for demanding work applications. However, the one constant limitation often faced is the range provided by the factory fuel tank. This is where Auxiliary Fuel Tanks For Pickup Trucks become an indispensable upgrade, transforming your vehicle from a standard workhorse into a long-haul champion.

An auxiliary fuel tank is essentially an additional fuel reservoir designed to significantly extend your truck’s operational range by supplementing its primary fuel supply. Far from being just a simple jerry can, these sophisticated systems integrate seamlessly with your truck, offering greater convenience, enhanced capability, and peace of mind, especially when fuel stations are scarce or prices are prohibitive. They are a game-changer for anyone who demands more from their pickup, providing the freedom to go further, work longer, and worry less about finding the next fill-up.

Auxiliary Fuel Tanks For Pickup Trucks: Expanding Your Horizons

Why Consider an Auxiliary Fuel Tank? The Undeniable Advantages

The decision to install an auxiliary fuel tank stems from a variety of practical needs and desires. Understanding these benefits can help you determine if this investment is right for you:

• Extended Range for Long Hauls and Remote Areas: This is the most obvious and compelling reason. Crossing vast stretches of highway, navigating off-road trails in the backcountry, or reaching remote job sites often means long distances between fuel stops. An auxiliary tank can double or even triple your truck’s range, eliminating range anxiety and allowing you to reach your destination without detours for fuel.
• Fuel Price Arbitrage: Savvy travelers and fleet operators know that fuel prices fluctuate significantly from one region to another. With an auxiliary tank, you can fill up when prices are low and avoid paying premium rates in more expensive areas, leading to substantial savings over time.
• Convenience and Time Savings: Fewer stops mean more efficient travel. Whether you’re on a tight schedule for a delivery or simply prefer uninterrupted journeys, an auxiliary tank reduces the frequency of refueling, saving valuable time.
• Work and Commercial Applications: For industries like construction, agriculture, logging, or mobile service, keeping equipment and vehicles fueled is critical. An auxiliary tank allows for on-site refueling of machinery, generators, or other vehicles, boosting productivity and reducing downtime.



• Overlanding and Off-Grid Adventures: For the avid adventurer, an auxiliary tank is a cornerstone of self-sufficiency. It provides the fuel needed to explore far off the beaten path, where gas stations are non-existent, and ensures you have enough to get back safely.
• Towing Heavy Loads: Towing significantly impacts fuel economy. An auxiliary tank mitigates this by providing the extra capacity needed to cover substantial distances even when pulling a heavy trailer, RV, or boat.

Types of Auxiliary Fuel Tanks: Finding Your Perfect Match

Auxiliary fuel tanks come in various designs, each suited for specific applications and preferences. Understanding the distinctions is crucial for making an informed choice:

1. Transfer Tanks:

   
   • Purpose: Primarily designed for transferring fuel from the tank to another vehicle or piece of equipment, rather than directly feeding the truck’s engine. They are often used for refueling ATVs, generators, boats, or other farm/construction machinery.
   • Mechanism: Typically require a pump (manual, 12V electric, or even gravity-fed with a hose) to move fuel out of the tank.
   • Materials: Commonly made from aluminum (lighter, corrosion-resistant) or steel (more robust, often cheaper).
   • Mounting: Almost exclusively mounted in the truck bed, secured to the floor or bed rails.
   • Legal Note: Generally less regulated than auxiliary tanks that directly feed the vehicle, but check local laws.

2. Auxiliary (Gravity Feed/Direct Feed) Tanks:

   • Purpose: These tanks are designed to directly supplement the truck’s main fuel tank. They are plumbed into the vehicle’s fuel system, often connecting to the main tank’s filler neck or fuel line.
   • Mechanism: Can be gravity-fed (fuel flows naturally from the auxiliary tank into the main tank as space becomes available) or utilize a dedicated pump to transfer fuel.
   • Integration: Proper integration often involves specialized valves (e.g., check valves, rollover valves), proper venting, and sometimes a dedicated fuel gauge or sender unit. Some advanced systems can even be controlled from the cab.
   • Mounting: Most commonly in the truck bed, but underbody options exist for maximizing bed space.
   • Legal Note: These are subject to stricter regulations (e.g., DOT compliance for commercial use, CARB compliance in California) due to their direct connection to the vehicle’s fuel system.

3. In-Bed Tool Box Combo Tanks:

   • Purpose: A popular choice for those who need both additional fuel capacity and secure storage for tools or equipment. These units combine a toolbox (often across the bed, near the cab) with an integrated fuel tank beneath or behind it.
   • Space-Saving: Excellent for maximizing bed utility by consolidating two essential items into one footprint.
   • Type: Can be either transfer tanks or direct-feed auxiliary tanks, depending on the design and plumbing.
   • Materials: Typically aluminum or steel.

4. Underbody/Frame-Mounted Tanks:

   • Purpose: Ideal for users who want to keep their truck bed completely clear for cargo. These tanks are custom-designed to fit within the truck’s frame rails, often replacing or supplementing the factory tank.
   • Complexity: Installation is significantly more complex, often requiring professional expertise due to precise fitment, exhaust rerouting, and intricate fuel line integration.
   • Integration: Often designed for seamless integration with the truck’s existing fuel system and gauge.
   • Capacity: Can offer substantial additional capacity without compromising bed space.

5. Diesel vs. Gasoline Tanks:

   • Material Compatibility: Diesel fuel is less corrosive than gasoline, so tanks designed for diesel can sometimes be made from different grades of aluminum or steel. Gasoline tanks require specific materials and coatings to prevent corrosion and maintain safety due to its higher volatility.
   • Safety Features: Gasoline tanks require more stringent safety features, including proper baffling to prevent sloshing, robust venting systems to manage vapor pressure, and often more robust construction to handle the inherent risks. Never use a diesel tank for gasoline, or vice versa, unless explicitly rated for both.

Key Considerations Before Installation

Before purchasing and installing an auxiliary fuel tank, a thorough evaluation of your needs and the associated factors is crucial:

• Capacity Needs: How much extra fuel do you realistically need? Tanks range from 30 gallons to over 100 gallons. Consider your typical trips, fuel consumption, and desired range extension.
• Material:
  • Aluminum: Lighter weight, excellent corrosion resistance, more expensive. Ideal for those concerned about payload or rust.
  • Steel: Heavier, generally more robust, typically less expensive. Can be prone to rust if not properly coated.
• Mounting Location:
  • In-Bed: Most common, easiest to install, but consumes bed space.
  • Underbody: Frees up bed space, but more complex installation, potentially lower capacity due to limited space.
• Fuel Type: Ensure the tank is explicitly rated for the fuel type (diesel or gasoline) your truck uses. Do not mix fuel types.
• Legality & Regulations: This is paramount.
  • DOT Compliance: For commercial vehicles, tanks must meet Department of Transportation (DOT) regulations for fuel containers.
  • State/Local Laws: Some states (e.g., California with CARB regulations) have specific requirements for auxiliary fuel systems, especially for gasoline. Always verify local laws regarding fuel transport and storage.
  • Insurance: Inform your insurance provider about the modification.
• Vehicle Compatibility:
  • Payload Capacity: Remember that fuel is heavy (diesel ~7.1 lbs/gallon, gasoline ~6.1 lbs/gallon). A 100-gallon tank full of diesel adds over 700 lbs, significantly impacting your truck’s payload capacity. Ensure your suspension can handle the added weight.
  • Existing Fuel System: Understand how the auxiliary tank will integrate with your truck’s current fuel lines, filler neck, and venting system.
• Installation Method: Are you comfortable with a DIY installation, or will you opt for professional help? Professional installation ensures compliance, safety, and proper integration.
• Fuel Transfer Method: Decide between gravity feed (simpler, but slower) or a pump (faster, more controlled, but requires electrical connection).
• Venting: Proper venting is critical for safety (preventing pressure buildup/vacuum) and proper fuel flow. Ensure the tank has an appropriate vent system, often with a rollover valve.
• Gauge/Monitoring: How will you monitor the fuel level in the auxiliary tank? Some come with their own gauges, others integrate with the truck’s existing system (though this is rare for direct integration), or you might rely on visual inspection.

Installation Guide (Simplified Overview)

While professional installation is recommended for direct-feed auxiliary tanks due to safety and complexity, here’s a simplified guide to the general steps involved:

1. Planning & Preparation:

   • Thoroughly research and select the correct tank type for your needs and fuel.
   • Gather all necessary tools, hoses, fittings, clamps, and electrical components.
   • Safety First: Disconnect the truck’s battery. Ensure good ventilation, no open flames, and have a fire extinguisher nearby.

2. Tank Placement and Mounting:

   • Carefully position the auxiliary tank in the desired location (e.g., truck bed).
   • Securely fasten the tank to the truck bed or frame using heavy-duty bolts, straps, or custom brackets. Ensure it cannot shift during braking or turns.

3. Plumbing (for Auxiliary/Direct Feed Tanks):

   • Connecting to Main Tank: This is the most critical step. Options include:
     • Filler Neck Connection: A common method involves a T-fitting installed in the main fuel filler neck, allowing fuel to flow from the auxiliary tank into the main tank.
     • Fuel Line Connection: More complex, involving tapping directly into the main fuel supply line, often requiring a fuel pump and check valves.
   • Hoses and Fittings: Use only fuel-rated hoses and fittings. Double-clamp all connections.
   • Check Valves: Install anti-siphon check valves to prevent fuel backflow and ensure proper gravity feed or pump operation.

4. Venting System:

   • Ensure the auxiliary tank has a dedicated vent line that extends above the tank’s fill level and is routed safely, often with a rollover valve to prevent spills in case of an accident.

5. Wiring (for Pumps/Gauges):

   • If using an electric pump or integrated fuel gauge, carefully route and connect wiring to the truck’s electrical system, using appropriate fuses and relays.

6. Testing and Leak Checks:

   • Before filling with fuel, conduct a dry fit and double-check all connections.
   • Fill the tank with a small amount of fuel and meticulously inspect all lines, fittings, and the tank itself for any leaks. Tighten connections as needed.
   • Test the transfer system (pump or gravity feed) to ensure proper operation.

Maintenance and Safety Tips

Owning an auxiliary fuel tank requires ongoing vigilance to ensure safe and reliable operation:

• Regular Inspections: Periodically check all hoses, fittings, mounting hardware, and the tank itself for any signs of leaks, corrosion, cracks, or damage.
• Keep Fuel Fresh: Don’t let fuel sit in the auxiliary tank for extended periods, especially gasoline, as it can degrade and cause issues. Rotate your fuel supply regularly.
• Proper Grounding: Ensure the tank is properly grounded to the truck’s frame to prevent static electricity buildup, which can be a fire hazard, especially with gasoline.
• Avoid Overfilling: Leave adequate air space in the tank for fuel expansion, particularly in hot weather, to prevent spills and pressure buildup.
• Understand Weight Limits: Always be mindful of your truck’s Gross Vehicle Weight Rating (GVWR) and Gross Axle Weight Ratings (GAWR). A full auxiliary tank adds significant weight, affecting braking, handling, and suspension.
• Driver Awareness: Be aware that a full auxiliary tank will change your truck’s center of gravity and handling characteristics. Drive cautiously until you adjust to the added weight.
• Use Proper Fuel: Only put the fuel type the tank is rated for into it.

Potential Challenges and Solutions

While auxiliary fuel tanks offer immense benefits, they do come with potential challenges:

• Weight Distribution/Payload Issues:
  • Challenge: Adding hundreds of pounds of fuel can overload your truck’s suspension or exceed its GVWR.
  • Solution: Assess your truck’s payload capacity beforehand. Consider suspension upgrades (e.g., airbags, heavier springs) if regularly hauling a full auxiliary tank.
• Cost of Tank and Installation:
  • Challenge: Quality tanks and professional installation can be a significant investment.
  • Solution: View it as a long-term investment that pays off in convenience, extended range, and potential fuel savings. Research various brands and installers for competitive pricing.
• Legality/Insurance Concerns:
  • Challenge: Non-compliance with regulations or not informing your insurer can lead to legal issues or voided coverage.
  • Solution: Thoroughly research and adhere to all federal, state, and local regulations. Always notify your insurance provider about the modification.
• Fuel Quality/Contamination:
  • Challenge: Stale fuel, condensation, or debris can contaminate your truck’s fuel system.
  • Solution: Use fuel stabilizers if storing fuel for long periods. Regularly inspect the tank and consider adding a fuel filter/water separator to the auxiliary system.
• Space Limitations in the Bed:
  • Challenge: In-bed tanks consume valuable cargo space.
  • Solution: Consider toolbox combo tanks for dual utility or underbody tanks if bed space is paramount. Choose a tank shape that minimizes obstruction.

Auxiliary Fuel Tank Price Table (Estimated Ranges)

Prices for auxiliary fuel tanks vary widely based on material, capacity, type (transfer vs. auxiliary), brand, and included features (e.g., pump, gauge). The following table provides general estimated price ranges:

Tank Type	Material	Capacity Range (Gallons)	Estimated Price Range (USD)	Key Features / Notes
Transfer Tank	Aluminum	30 – 100+	$500 – $1,500+	Lighter, corrosion-resistant, typically pump-ready.
Transfer Tank	Steel	30 – 100+	$400 – $1,200+	More robust, heavier, often powder-coated.
Auxiliary/Gravity Feed	Aluminum	40 – 100+	$800 – $2,500+	Direct feed to main tank, includes plumbing components.
Auxiliary/Gravity Feed	Steel	40 – 100+	$700 – $2,000+	Direct feed, may require more complex installation.
Tool Box Combo Tank	Aluminum	40 – 90	$1,000 – $2,800+	Combines fuel storage with secure tool storage.
Tool Box Combo Tank	Steel	40 – 90	$800 – $2,500+	Dual utility, can be transfer or auxiliary type.
Underbody/Frame-Mounted	Steel	30 – 60+	$1,500 – $4,000+	Frees up bed space, complex installation, often custom.

Note: These prices generally do not include installation costs, which can range from a few hundred dollars for simple transfer tanks to over a thousand for complex auxiliary or underbody systems.

Frequently Asked Questions (FAQ)

Q1: Are auxiliary fuel tanks legal?
A1: Yes, in most cases, but legality depends on the tank type, your specific state/local regulations, and whether it’s for commercial or personal use. Tanks directly connected to the vehicle’s fuel system (auxiliary tanks) typically have stricter requirements (e.g., DOT compliance, CARB compliance in California) than simple transfer tanks. Always verify local laws before purchase and installation.

Q2: Will installing an auxiliary tank void my truck’s warranty?
A2: It could potentially void parts of your powertrain warranty if the dealership can prove the auxiliary tank directly caused a failure in the fuel system or related components. It’s advisable to check with your truck manufacturer or dealership before installation, especially for direct-feed systems. Using a reputable installer and high-quality, compliant components can help mitigate risks.

Q3: Can I install an auxiliary fuel tank myself?
A3: Transfer tanks are generally straightforward for a DIY enthusiast. However, direct-feed auxiliary tanks that plumb into your truck’s fuel system are significantly more complex and carry higher safety risks (fuel leaks, fires). Professional installation is highly recommended for these types to ensure proper function, safety, and compliance with regulations.

Q4: Do I need a special pump to transfer fuel?
A4: For transfer tanks, yes, you’ll need a pump (manual hand pump, 12V electric pump, or gravity feed kit). For direct-feed auxiliary tanks, some are gravity-fed (fuel flows into the main tank as space opens up), while others use a small electric pump to actively transfer fuel.

Q5: How much weight does an auxiliary fuel tank add to my truck?
A5: The tank itself adds weight (aluminum is lighter than steel). However, the significant weight comes from the fuel: diesel weighs approximately 7.1 lbs per gallon, and gasoline weighs about 6.1 lbs per gallon. A 100-gallon tank full of diesel adds over 700 lbs to your truck’s payload. Always factor this into your truck’s Gross Vehicle Weight Rating (GVWR).

Q6: Can I use the same auxiliary tank for both gasoline and diesel?
A6: Absolutely NOT. Tanks are specifically designed and rated for either gasoline or diesel due to differences in material compatibility, volatility, and safety requirements. Using a tank for the wrong fuel type is extremely dangerous and can lead to severe damage, leaks, or fire.

Conclusion: Fueling Your Freedom

Auxiliary fuel tanks for pickup trucks are more than just an add-on; they are a strategic upgrade that unlocks new levels of freedom, efficiency, and capability for your vehicle. Whether you’re a long-haul trucker, an avid overlander, a dedicated contractor, or simply someone who appreciates the convenience of fewer fuel stops, the benefits are clear.

However, the decision to install one should be approached with careful consideration. From understanding the different types and capacities to navigating legal requirements and ensuring safe installation, diligence is key. By investing in the right auxiliary fuel system and maintaining it properly, you’re not just buying more fuel capacity; you’re buying the peace of mind to go further, work smarter, and truly explore the horizons with your pickup truck.