Long-haul truckers and remote workers understand the frustration of running low on fuel miles away from the nearest station completely. Extended range capability becomes essential when your job or lifestyle demands traveling through areas where fuel stops are scarce or nonexistent. Investing in the best auxiliary diesel fuel tank transforms your pickup truck into a reliable workhorse capable of tackling any distance without range anxiety limiting your options.
These specialized tanks mount directly in your truck bed and transfer diesel fuel to your factory tank through gravity feed or pump systems automatically. My years of experience hauling equipment across remote construction sites taught me which tank features genuinely matter versus marketing hype that wastes money.
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Dee Zee DZ91752X (39 gallon) Narrow Auxiliary... | Check Price Here |
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Dee Zee DZ92740XB (43 gallon) Auxiliary... | Check Price Here |
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Dee Zee DZ91742XB (92 gallon) Auxiliary... | Check Price Here |
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Dee Zee DZ91741X (80 gallon) Auxiliary Diesel... | Check Price Here |
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RDS MFG INC - 72548 Fuel Transfer... | Check Price Here |
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Dee Zee DZ92740X (43 gallon) Auxiliary Diesel... | Check Price Here |
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Dee Zee DZ92751XB Auxiliary Diesel Fuel... | Check Price Here |
Whether you manage a fleet, work in agriculture, or simply enjoy extended off-road adventures, proper fuel capacity keeps you moving when others stop. Let me share insights that help you choose equipment matching your specific needs perfectly.
How Impact Best Auxiliary Diesel Fuel Tank
Understanding how auxiliary fuel capacity affects your operations reveals why serious professionals invest in quality equipment thoughtfully. Standard factory fuel tanks provide adequate range for typical commuting but fall short when real work demands extended operation without interruption. The difference between reaching your destination and being stranded becomes critically important in remote locations.
Extended driving range eliminates the constant search for fuel stations that interrupts your schedule and reduces productivity significantly. You can plan routes based on efficiency rather than fuel availability, choosing shorter paths through areas lacking commercial services. This freedom transforms how you approach long-distance travel entirely.
Cost savings accumulate over time when you purchase diesel at lower prices and avoid premium charges at remote stations consistently. Filling your auxiliary tank at familiar locations where prices remain competitive reduces your overall fuel expenses measurably. These savings offset the initial equipment investment relatively quickly for high-mileage operators.
Equipment refueling capability extends beyond just your truck to include tractors, generators, and other diesel-powered machinery requiring fuel. Having fuel readily available in your truck bed eliminates separate trips to fuel stations when working remote job sites. This convenience improves workflow efficiency dramatically for contractors and agricultural operators.
Emergency preparedness improves substantially when your vehicle carries enough fuel to reach safety regardless of circumstances encountered. Natural disasters, civil emergencies, and unexpected detours become manageable rather than potentially dangerous situations requiring rescue. This security provides peace of mind for families traveling through unfamiliar territory.
Vehicle resale value often increases when quality auxiliary fuel systems are professionally installed and maintained throughout ownership properly. Buyers recognize the added utility these systems provide for commercial and recreational applications equally well. Your investment retains value rather than depreciating like many vehicle accessories do rapidly.
What Is Best Auxiliary Diesel Fuel Tank
Selecting optimal fuel storage equipment requires understanding which features matter most for your specific applications and requirements. Not every tank suits every situation, so matching capabilities to your actual needs produces best results consistently. The ideal tank for fleet operations differs substantially from what recreational users require for their adventures.
Material construction fundamentally affects durability, weight, and long-term corrosion resistance across varying environmental conditions encountered. Aluminum tanks offer lightweight strength with natural corrosion resistance that suits most applications excellently. Steel options provide maximum durability at lower cost but require quality coatings to prevent rust formation over time.
Capacity requirements depend on your typical travel distances and the fuel consumption characteristics of your specific vehicle configuration. Larger tanks extend range proportionally but consume more bed space that might otherwise hold tools or cargo. Finding the right balance between capacity and space preservation requires honest assessment of actual needs.
Integration systems determine how fuel transfers from your auxiliary tank to the factory tank during normal operations automatically. Gravity feed systems use simple physics to move fuel without pumps or electricity, reducing complexity and potential failure points. Pump-based systems offer faster transfer rates and more control over the refueling process entirely.
Mounting configuration affects both installation complexity and how the tank interacts with other bed accessories you might use regularly. Low-profile designs fit beneath tonneau covers while taller tanks may interfere with cover installation or cargo space utilization. Consider your complete truck bed setup when evaluating tank dimensions carefully.
- Dee Zee 39 Gallon Narrow
- Dee Zee 43 Gallon Black
- Dee Zee 92 Gallon Combo
- Dee Zee 80 Gallon Toolbox
- RDS 60 Gallon Combo
- Dee Zee 43 Gallon Aluminum
- Dee Zee 51 Gallon Black
- Dee Zee Connector Kit
- RDS Transfer Tank System
Comparison Table of Best Auxiliary Diesel Fuel Tank
| Tank Model | Capacity | Material |
|---|---|---|
| Dee Zee DZ91752X | 39 Gallons | Brite-Tread Aluminum |
| Dee Zee DZ92740XB | 43 Gallons | Black Aluminum |
| Dee Zee DZ91742XB | 92 Gallons | Black Aluminum |
| Dee Zee DZ91741X | 80 Gallons | Brite-Tread Aluminum |
| RDS 72548 | 60 Gallons | Aluminum |
| Dee Zee DZ92740X | 43 Gallons | Brite-Tread Aluminum |
| Dee Zee DZ92751XB | 51 Gallons | Black Aluminum |
| Dee Zee DZ97960 | Connector | Kit Components |
| Dee Zee DZ97962 | Connector | Kit Components |
10 Best Auxiliary Diesel Fuel Tank Reviews
Dee Zee 39 Gallon Narrow Tank
Dee Zee DZ91752X (39 gallon) Narrow Auxiliary...
Designed for truck owners who need additional fuel capacity without sacrificing significant bed space for cargo hauling requirements. The narrow profile fits alongside other equipment or against one side of the bed, leaving room for tools and materials you need regularly. This versatility makes it popular among contractors who balance fuel needs with cargo requirements daily.
Heavy gauge Brite-Tread aluminum construction provides excellent corrosion resistance that withstands years of outdoor exposure without degradation. The signature diamond plate pattern adds visual appeal while providing non-slip surface texture for safety purposes. Quality welding throughout ensures leak-free operation under the varying conditions truck beds experience constantly.
Internal stability baffles prevent fuel from sloshing excessively during acceleration, braking, and cornering maneuvers while driving normally. This design feature reduces stress on tank construction while improving vehicle handling with full fuel loads present. The baffles add structural strength that extends tank service life significantly beyond unbaffled alternatives.
The radius curve design eliminates sharp corner welds that represent common failure points in lesser quality tank construction methods. Rounded corners distribute stress more evenly across the tank structure during impacts and pressure cycling constantly. This engineering detail reflects the quality approach that defines the Dee Zee product line consistently.
Top Features:
- Narrow profile preserves bed space for tools and cargo
- Heavy gauge Brite-Tread aluminum construction resists corrosion effectively
- Internal baffles prevent fuel sloshing and add structural strength
- Radius curve design eliminates stress-concentration weld points
- Lockable cap and venting coupler included for security
“Dee Zee Auxiliary Tanks provide a safe and convenient means for transporting non-flammable liquids. Constructed of heavy gauge Brite-Tread aluminum with radius curve design that eliminates key weld pressure points.”
Dee Zee 43 Gallon Black Tank
Dee Zee DZ92740XB (43 gallon) Auxiliary...
The black powder coat finish appeals to truck owners preferring a stealthier appearance that blends with modern truck styling trends. Beyond aesthetics, the coating provides additional corrosion protection over the already rust-resistant aluminum construction underneath. This dual-layer protection ensures long service life even in harsh environmental conditions encountered.
Forty-three gallons of additional capacity significantly extends your driving range without requiring the bed space larger tanks demand. This size represents an excellent balance between added range and retained cargo space for most applications encountered. Many users find this capacity perfectly matches their needs without excess.
Compatibility with Dee Zee’s gravity feed connector kits enables automatic fuel transfer to your factory tank during normal operation. The system uses simple gravity physics without requiring electrical connections or pump installations for operation. This simplicity reduces potential failure points while providing reliable fuel transfer when needed.
The tank meets Federal DOT requirements for UN31B tanks, ensuring legal compliance for transportation purposes across all jurisdictions. Hydrostatic pressure testing during manufacturing confirms structural integrity before tanks reach customers for installation. These certifications provide confidence in safety and regulatory compliance.
Top Features:
- Black powder coat finish provides sleek appearance and added protection
- 43-gallon capacity balances range extension with space preservation
- Compatible with gravity feed connector kits for automatic transfer
- Meets Federal DOT requirements for safe transportation
- Hydrostatically pressure tested for structural integrity verification
“Dee Zee Transfer Tanks provide a safe and convenient means for transporting non-flammable liquids. Black powder coat finish with radius curve design eliminates key weld pressure points.”
Dee Zee 92 Gallon Combo Tank
Dee Zee DZ91742XB (92 gallon) Auxiliary...
Serious professionals requiring maximum fuel capacity combined with tool storage appreciate this integrated solution completely. The 92-gallon fuel capacity dramatically extends range while the mounted toolbox keeps essential equipment secure and organized. This combination maximizes utility for commercial operators who need both capabilities regularly.
The black aluminum construction withstands demanding commercial use while maintaining attractive appearance throughout service life. Heavy gauge material resists damage from tools and equipment placed on or near the tank during work. Quality welds ensure leak-free operation even under the stresses commercial applications create.
Integrated toolbox mounting eliminates the need for separate crossover boxes that would compete for bed rail space with the tank. The combination design uses available space more efficiently than separate components could achieve individually. This efficiency matters when every inch of bed space serves important purposes.
Three stability baffles within the tank prevent fuel movement that could affect vehicle handling during normal driving operations. These baffles also strengthen the overall tank structure against the stresses mounting and road vibration create. The improved handling characteristics make driving with full fuel loads more predictable.
Top Features:
- 92-gallon capacity provides maximum range extension possible
- Integrated toolbox eliminates separate storage requirements
- Black aluminum construction resists corrosion and damage
- Triple internal baffles improve handling and tank strength
- Lockable cap and drainage plug for security and maintenance
“Dee Zee Auxiliary Tanks provide a safe and convenient means for transporting non-flammable liquids with the convenience of a tool box mounted to the tank. Can be connected to gravity flow kit to syphon fuel directly into your vehicle’s diesel gas tank.”
Dee Zee 80 Gallon Toolbox Combo
Dee Zee DZ91741X (80 gallon) Auxiliary Diesel...
This Brite-Tread aluminum version offers the same integrated functionality as the black version with the classic diamond plate appearance. The bright aluminum finish complements trucks with chrome accents or traditional styling preferences effectively. Many operators prefer this look over powder-coated alternatives.
Eighty gallons of fuel capacity provides substantial range extension while the toolbox component keeps frequently needed items readily accessible. The slightly smaller fuel capacity compared to the 92-gallon version trades some range for improved cargo space utilization. This balance suits operators who need both capabilities without maximizing either.
Construction quality matches the premium standards Dee Zee maintains across their entire product line consistently throughout manufacturing. Certified welds, proper material gauges, and thorough testing ensure every tank performs as expected throughout service life. Quality control procedures prevent defective products from reaching customers.
The tank connects to optional gravity feed connector kits enabling automatic fuel transfer to your factory tank during stops. This feature maintains your primary tank at full capacity without manual pumping or attention during normal operations. Simply park and let gravity do the work of transferring fuel efficiently.
Top Features:
- Certified auxiliary fuel transfer tank with mounted tool chest
- Non-rusting .125 Brite-Tread aluminum construction throughout
- Connects to OEM fuel line for direct diesel transfer
- Meets Federal DOT requirements for safe transportation
- Vented cap prevents pressure buildup during operation
“Certified Auxiliary Fuel Transfer Tank with Mounted Tool Chest. Connect to OEM Fuel Line to Transfer Diesel Fuel and Meets Federal DOT Requirements. Non-Rusting .125 Brite-Tread Aluminum with Vented Cap.”
RDS 60 Gallon Combo Tank
RDS MFG INC - 72548 Fuel Transfer...
RDS has built their reputation on quality fuel storage solutions that commercial operators trust for demanding applications daily. This 60-gallon combination tank provides substantial fuel capacity with integrated toolbox storage for complete utility. The design suits operators who need reliable fuel transport with organized tool access.
Aluminum construction throughout ensures corrosion resistance that steel alternatives require coatings to achieve adequately. The natural oxidation of aluminum creates a protective layer that prevents further degradation automatically over time. This self-protecting characteristic extends service life without requiring ongoing maintenance.
The integrated toolbox design positions storage where you need it most without consuming additional bed space for separate units. Tools remain secure and dry while fuel capacity ensures you reach your destination without unexpected stops. This dual functionality appeals to practical-minded commercial operators.
RDS offers auxiliary fueling capability through their optional diesel install kit that connects directly to your factory tank. The gravity feed system transfers diesel fuel automatically without requiring electrical pumps or complex installations entirely. Simple, reliable operation characterizes the RDS approach to auxiliary fuel systems.
Top Features:
- 60-gallon capacity provides excellent range extension
- Integrated toolbox design maximizes bed space utilization
- Aluminum construction ensures long-term corrosion resistance
- Compatible with RDS diesel install kit for gravity transfer
- Full assortment of sizes and configurations available
“Most RDS transfer tanks also provide auxiliary fueling. RDS offers a full assortment of tanks in various capacities and dimensions to fit your needs. Diesel fuel can gravity feed from the bottom of your RDS tank.”
Dee Zee 43 Gallon Aluminum Tank
Dee Zee DZ92740X (43 gallon) Auxiliary Diesel...
The classic Brite-Tread aluminum finish remains popular among truck owners who appreciate the traditional diamond plate appearance. This finish has defined truck accessories for decades while providing practical non-slip surface characteristics simultaneously. The bright aluminum complements various truck colors and style preferences effectively.
Forty-three gallons represents a sweet spot capacity that adds significant range without overwhelming your bed space completely. This size fits most truck beds comfortably while leaving room for other equipment you need to carry regularly. The balanced approach suits many different applications and users.
Quality construction using heavy gauge aluminum ensures durability that matches the demands commercial and recreational users place on equipment. Precision welding throughout prevents leaks while the radius curve design eliminates stress concentration points that cause premature failures. Engineering excellence defines every aspect of this tank.
The tank accepts Dee Zee connector kits that enable automatic fuel transfer to your factory diesel tank through gravity. This integration transforms a simple transfer tank into a range-extending auxiliary fuel system automatically. The convenience of automatic transfer justifies the additional kit investment for most users.
Top Features:
- Classic Brite-Tread aluminum diamond plate appearance
- 43-gallon capacity balances range and space effectively
- Heavy gauge construction ensures commercial-grade durability
- Compatible with gravity feed connector kit systems
- Stability baffles prevent sloshing and add strength
“Dee Zee Auxiliary Tanks provide a safe and convenient means for transporting non-flammable liquids. Constructed of heavy gauge Brite-Tread aluminum with stability baffles, lockable cap, drainage plug, and venting coupler.”
Dee Zee 51 Gallon Black Tank
Dee Zee DZ92751XB Auxiliary Diesel Fuel...
Stepping up to 51 gallons provides additional range over the 43-gallon options without requiring significantly more bed space. This incremental capacity increase appeals to users who want maximum range within compact tank dimensions available. Every extra gallon matters when stations are many miles apart unexpectedly.
The black powder coat finish over aluminum construction provides dual-layer protection against environmental damage continuously. Appearance remains attractive longer than uncoated aluminum that naturally oxidizes with varying visual results over time. Many truck owners prefer the consistent black appearance this finish provides.
Three internal stability baffles manage fuel movement during vehicle operation while strengthening overall tank construction simultaneously. Reduced sloshing improves handling characteristics when the tank contains significant fuel volume during driving. The structural benefits extend tank service life considerably.
Designed for diesel fuel transport and auxiliary fueling applications when combined with appropriate connector kits separately. The tank meets DOT requirements for safe transportation of non-flammable liquids across all jurisdictions consistently. Proper certification ensures legal compliance for commercial and private users alike.
Top Features:
- 51-gallon capacity extends range substantially
- Black powder coat provides lasting appearance protection
- Triple internal baffles for stability and strength
- DOT compliant for safe transportation requirements
- Lockable cap prevents unauthorized access
“Dee Zee Transfer Tanks provide a safe and convenient means for transporting non-flammable liquids. Constructed of Brite-Tread aluminum with black powder coat finish and radius curve design.”
Dee Zee Connector Kit DZ97960
Dee Zee DZ97960 Auxiliary Transfer Tank...
This connector kit transforms any compatible Dee Zee auxiliary tank into a true best auxiliary diesel fuel tank system automatically. The kit includes everything needed to connect your tank directly to your vehicle’s fuel line for gravity feed operation. Installation requires some cutting of the OEM fuel hose but provides foolproof operation afterward.
Gravity feed operation uses simple physics rather than complex pumps or electrical systems that could fail unexpectedly. Fuel flows from the auxiliary tank to your factory tank whenever levels differ sufficiently to create flow pressure. This simplicity ensures reliable operation without requiring ongoing maintenance attention.
The kit includes all hoses and mounting hardware needed for complete installation without additional purchases required. Clear instructions guide the installation process for those with basic mechanical skills and proper tools. Professional installation remains an option for those preferring expert assistance.
Compatibility covers most diesel trucks with appropriate fuel line access for the connection procedure described. Ford, GM, and Ram trucks represent the primary applications where this kit performs as designed reliably. Verify your specific vehicle compatibility before purchasing to ensure proper fit.
Top Features:
- Connects auxiliary tank directly to vehicle fuel line
- Uses gravity feed system without electrical requirements
- Includes all hoses and mounting hardware needed
- Ensures foolproof operation after proper installation
- Compatible with most major diesel truck brands
“Dee Zee Connector Kit gives you the ability to refuel your diesel fuel tank via gravity feed system. Connect to your Dee Zee Auxiliary Tank to your vehicle’s fuel line to always keep your tank full. All hoses and mounting hardware included.”
Dee Zee Connector Kit DZ97962
DEE ZEE DZ97962 Auxiliary Transfer Tank...
This updated connector kit provides similar functionality to the DZ97960 with modifications for newer vehicle fuel systems encountered. Changes in fuel line routing and connections across model years require updated kit components for proper compatibility. This version addresses those requirements specifically.
The gravity feed principle remains identical, using fuel level differential to create flow between tanks automatically. No pumps or electrical connections are required for basic operation during normal use patterns. This simplicity appeals to users preferring minimal system complexity.
Installation instructions address the specific requirements of newer fuel systems that differ from earlier designs significantly. Following these instructions carefully ensures proper operation without triggering check engine warnings in some vehicles. Understanding your specific vehicle helps achieve best results.
The kit serves as the essential link between auxiliary fuel storage and practical range extension for your diesel truck. Without this connection, auxiliary tanks require manual pumping to transfer fuel to your factory tank inefficiently. The connector kit enables automatic operation that maximizes convenience completely.
Top Features:
- Updated design for compatibility with newer vehicles
- Gravity feed operation without electrical requirements
- Includes all necessary hoses and mounting components
- Clear instructions for proper installation procedures
- Listed for diesel fuel operation only
“Dee Zee Auxiliary Fuel Line Connector Kit gives you the ability to refuel your diesel fuel tank via gravity feed system. Connect to your Dee Zee Auxiliary Tank to your vehicle’s fuel line to refill your tank when needed.”
What Capacity Auxiliary Diesel Fuel Tank Should You Choose
Tank capacity selection depends heavily on your specific driving patterns and how far you typically travel between convenient fuel stops. Calculate your vehicle’s fuel consumption rate and multiply by the additional range you need consistently. This mathematical approach prevents both under-sizing that limits utility and over-sizing that wastes bed space unnecessarily.
Consider your truck bed dimensions carefully before selecting tank capacity that might not physically fit your available space. Measure length, width, and height limitations including any obstructions from wheel wells or other equipment already installed. Tank manufacturers provide dimensions that help verify fit before purchasing.
Weight considerations become important because fuel weighs approximately 7 pounds per gallon for diesel specifically. A full 100-gallon tank adds 700 pounds to your truck’s gross weight, potentially affecting handling and payload capacity significantly. Ensure your vehicle can safely handle the additional weight when fully loaded.
Future needs deserve consideration because auxiliary tank installation represents significant investment of time and money realistically. Choosing slightly larger capacity than your current needs accommodate anticipates potential changes in usage patterns ahead. This forward-thinking approach prevents premature upgrades.
How Do Gravity Feed Auxiliary Diesel Fuel Tank Systems Work
Gravity feed systems use the fundamental principle that liquids flow from higher to lower elevations when given a path. Your auxiliary tank mounts at a level higher than your factory tank, allowing fuel to flow downward through connecting hoses. This simple physics eliminates the need for pumps or electrical systems entirely.
The connecting hose includes a valve that you can open or close to control when fuel transfers between tanks. During driving, the valve typically remains closed to prevent continuous transfer that could trigger fuel system warnings. You open the valve during stops to replenish your factory tank from auxiliary reserves.
Some newer vehicles with electronic fuel monitoring systems may display warnings if continuous fuel transfer occurs during operation. The gravity feed kit instructions address this issue by recommending valve closure during driving periods. Following these guidelines prevents unnecessary warning lights and codes.
Installation connects the auxiliary tank outlet to your factory tank’s fuel line at an appropriate location below the main tank. Fuel flows through this connection whenever the valve opens and level differential exists between tanks. The process continues until levels equalize or you close the valve manually.
Are Auxiliary Diesel Fuel Tanks Legal for Road Use
Federal regulations govern the transportation of flammable liquids including diesel fuel in auxiliary tank applications directly. Tanks meeting DOT UN31B requirements satisfy these regulations for private, non-commercial transportation purposes specifically. Most quality auxiliary tanks include this certification for legal compliance assurance.
Commercial transportation of diesel fuel in auxiliary tanks may require additional permits or certifications beyond basic DOT compliance. Regulations vary between states and applications, so verifying requirements for your specific situation remains essential. Professional fleet managers understand these requirements thoroughly.
Auxiliary tanks intended for refueling your own vehicle differ legally from tanks used to sell or distribute fuel commercially. The private use exemption simplifies requirements for typical truck owners using auxiliary fuel for personal transportation. Commercial distribution involves substantially different regulatory requirements.
Insurance considerations may affect coverage when auxiliary fuel tanks are installed without proper certification documentation. Inform your insurance provider about auxiliary tank installation to ensure your coverage remains valid throughout ownership. Documentation of proper installation supports claims if accidents occur.
What Materials Work Best for Auxiliary Diesel Fuel Tanks
Aluminum construction dominates the auxiliary fuel tank market due to its excellent strength-to-weight ratio and natural corrosion resistance. The material requires no coating to prevent rust, though powder coats are often added for appearance purposes. Lightweight characteristics benefit vehicle performance and payload capacity preservation.
Steel tanks offer maximum durability at lower cost but require quality coatings to prevent rust formation over time consistently. Powder coating or galvanizing protects steel effectively when properly applied during manufacturing processes. Weight increases significantly compared to equivalent aluminum tanks.
High-density polyethylene tanks resist corrosion and impact damage while offering the lightest weight option available typically. However, fuel permeation through plastic can occur over extended periods, potentially creating vapor issues. These tanks suit specific applications where their characteristics provide advantages.
Welding quality matters more than base material selection for preventing leaks and ensuring long service life consistently. Quality manufacturers employ certified welders and test every tank before shipment to customers awaiting delivery. Purchasing from reputable brands ensures proper construction quality throughout.
How Difficult Is Installing an Auxiliary Diesel Fuel Tank
Basic auxiliary tank installation involves securing the tank to your truck bed using provided mounting hardware properly. Most truck owners with moderate mechanical skills can complete this portion within a few hours using common tools. Following manufacturer instructions carefully ensures secure, safe mounting throughout.
Connecting gravity feed systems requires more technical skill including identifying proper fuel line connection points accurately. Some cutting of factory fuel hoses is typically required to splice in the auxiliary connection appropriately. This process creates the permanent link between tanks enabling gravity feed operation.
Electrical pump installations add complexity through wiring requirements and pump mounting considerations not present in gravity systems. These installations may benefit from professional assistance to ensure proper electrical connections and safe operation. The added complexity provides faster transfer rates when needed.
Professional installation services are available through truck accessory shops and automotive service centers familiar with auxiliary tank systems. The cost varies based on tank complexity and vehicle-specific requirements encountered during installation procedures. Professional work often includes warranty coverage for installation quality.
Can You Use an Auxiliary Diesel Fuel Tank with a Tonneau Cover
Low-profile auxiliary tank designs specifically accommodate tonneau cover installation without interference or removal requirements. These tanks feature reduced heights that fit beneath covers while still providing useful fuel capacity for range extension. Manufacturers specify tonneau compatibility in product descriptions for easy identification.
Some tanks require specific pump mounting configurations that position pumps lower than standard designs typically allow. Side-mounted pumps and recessed filler necks enable tonneau cover installation without modifications to either component. Verify specific compatibility before purchasing when tonneau cover integration matters.
Traditional transfer tanks with top-mounted pumps generally prevent tonneau cover installation without removing the pump entirely. This limitation affects functionality since pumping capability disappears when the cover installs over the tank. Consider your priorities when selecting between cover compatibility and pumping features.
Combination approaches use low-profile auxiliary tanks for covered applications while separate transfer tanks remain available for equipment refueling. This dual-tank strategy maximizes flexibility when both capabilities serve important purposes in your operations. Space and budget determine feasibility for this approach.
How Much Does the Best Auxiliary Diesel Fuel Tank Cost
Entry-level auxiliary tanks start around $400-600 for basic aluminum construction without integrated toolboxes or premium features. These tanks provide core functionality at accessible price points for budget-conscious buyers with basic needs. Quality varies at this level, so brand reputation matters significantly.
Mid-range options between $600-1000 include better construction quality, larger capacities, and additional features like integrated toolboxes. Most serious users find appropriate solutions within this price range for their specific requirements. The value proposition improves substantially over entry-level alternatives.
Premium auxiliary fuel systems exceeding $1000 include advanced features like electronic transfer systems and smartphone integration capabilities. These systems suit professional applications where maximum functionality justifies higher investment levels. Commercial operators often find premium features worthwhile.
Installation costs add $100-500 depending on complexity and whether professional services or DIY approaches are chosen. Gravity feed connector kits cost $100-200 additionally while pump systems range higher based on features included. Budget for complete system cost rather than tank price alone.
How Do You Maintain an Auxiliary Diesel Fuel Tank
Regular inspection catches developing problems before they create significant issues affecting tank function or safety. Check mounting hardware tightness, hose condition, and cap seal integrity periodically throughout the ownership period. These simple checks prevent most common problems from developing.
Keep fuel fresh by using stored diesel within reasonable time frames rather than letting it sit indefinitely in tanks. Diesel fuel degrades over time, potentially creating gelling or microbial growth that affects engine performance negatively. Use fuel treatments for extended storage periods.
Clean the tank interior periodically to remove accumulated sediment that all diesel fuel contains in small quantities. Sediment buildup can eventually affect fuel transfer or clog filters in connected systems over time. Professional cleaning services handle this task efficiently.
Inspect welds and seams for any signs of leakage that would indicate developing structural problems requiring attention. Even small leaks represent both fuel loss and potential safety hazards that warrant immediate repair. Address any leakage promptly.
Final Thoughts
After years of depending on auxiliary fuel capacity for remote construction work across multiple states, my recommendation centers on matching tank size to your actual needs rather than maximizing capacity unnecessarily. The Dee Zee 43 Gallon options provide excellent balance between range extension and retained bed space for most users. Contractors needing maximum capacity combined with tool storage should consider the Dee Zee 80 or 92 Gallon Combo tanks.
Quality matters tremendously because your best auxiliary diesel fuel tank will experience constant vibration, temperature changes, and the stresses truck beds create during normal use. Investing in reputable brands like Dee Zee or RDS ensures proper construction that prevents the leaks and failures cheaper alternatives risk experiencing.
Always purchase the appropriate connector kit for your specific vehicle when planning gravity feed installations. This integration transforms simple storage into true range extension capability that keeps your factory tank full automatically during stops.