Auxiliary Fuel Tank With Pump To Main Tank: What You Need To Know
An auxiliary fuel tank with a pump to the main tank is a practical and effective solution for significantly increasing your vehicle's driving range. This system allows you to carry extra fuel beyond your vehicle's original fuel capacity and transfer it on-demand to the main tank, eliminating the need for frequent fuel stops during long trips, remote travel, or when carrying heavy loads. Choosing the right system and installing it correctly is crucial for safety, reliability, and performance.
Understanding the Core System
An auxiliary fuel tank with pump to main tank setup consists of a few fundamental components working together. The auxiliary tank is a separate container, designed to hold gasoline or diesel fuel, installed somewhere on your vehicle (common locations include the truck bed, under-bed toolboxes, or replacing the spare tire). A specialized fuel pump is integrated into this system. This isn't a simple transfer pump; it's designed to safely and reliably move fuel from the auxiliary tank into the vehicle's main fuel tank. Fuel lines connect the auxiliary tank to the pump and then from the pump to the main tank. A filler neck or port allows you to refuel the auxiliary tank directly. Crucially, a control switch inside the cabin enables the driver to activate the fuel transfer pump as needed. Finally, wiring connects the pump to the vehicle's electrical system (usually fused and often switched via a relay) and to the control switch inside the vehicle.
Key Benefits: Why Install One?
The primary motivation is a substantial increase in driving range. This is invaluable for long-haul truckers, travelers exploring remote areas far from fuel stations, RV owners, and anyone regularly towing heavy trailers that drastically reduce fuel economy. By reducing the frequency of fuel stops, particularly where stations are scarce or fuel prices are higher, you save considerable time and can plan travel more freely. Carrying extra fuel avoids relying on potentially unreliable fuel containers or unsafe siphoning methods. Knowing you have ample reserves provides significant peace of mind during extended journeys. For work trucks or off-road vehicles operating in demanding environments, reduced downtime for refueling means increased operational efficiency.
Choosing the Right Auxiliary Fuel Tank System
Selecting the best system requires careful consideration of several factors. Tank capacity should align with your actual needs. While larger capacities offer more range, consider the impact on payload, vehicle handling, and available installation space. Tanks are typically made from steel (durable, heavy) or high-density polyethylene (HDPE - corrosion-resistant, lighter weight). Ensure the tank material is compatible with your fuel type (gasoline or diesel). The pump type is critical. Direct current pumps designed specifically for fuel transfer are essential. Key considerations include flow rate (gallon-per-hour or liter-per-hour), power draw (amps), voltage (12V or 24V compatible), pressure rating, and whether it includes integrated check valves and thermal protection. Diesel pumps are generally more robust, while gasoline pumps must meet strict safety standards due to higher flammability.
Manual control systems use a simple dash switch to activate the pump when fuel transfer is desired. Semi-automatic systems include logic to prevent overfilling by monitoring the main tank level (either electronically or via mechanical float switches) and automatically stopping the pump transfer when the main tank is full, preventing dangerous spills. Choosing between manual and semi-automatic largely depends on convenience and safety tolerance. Tank installation location dictates shape and size. Common choices include bed-mounted (often within truck-bed toolboxes), under-bed mounts (utilizing space below the bed floor), and spare-tire well replacements. Ensure the chosen tank integrates well with your specific vehicle model. Fuel lines must be manufacturer-approved for your fuel type, pressure-rated, and correctly sized for the pump. Wiring must be appropriately sized for the pump's amperage draw, fused near the power source, and typically routed via a relay controlled by the dash switch. Quality auxiliary tanks include safety features like rollover vent valves and pressure/vacuum relief valves. Integration with the vehicle's existing vents or independent venting is crucial. Secondary containment options, like a spill tub, offer additional environmental protection. The filler neck must be accessible and comply with regulations, ideally featuring a locking cap. Consider how easily you can refill it during your travels.
Essential Safety Considerations
Fuel system safety is paramount. Always use components (tank, pump, lines, fittings) explicitly rated and certified for automotive fuel use according to relevant standards. Correct fuel line routing away from sharp edges, heat sources, moving parts, and electrical wiring with proper abrasion protection (loom, grommets) is mandatory. Follow the manufacturer's specified installation location – improper mounting can compromise safety and vehicle handling. High-quality fittings specifically designed for fuel systems prevent leaks. Robust electrical connections, weatherproofing where necessary, and securing wires properly prevent shorts and fire hazards. Ensure adequate venting for both the auxiliary and main tank system to avoid pressure buildup or vacuum lock. Understand your vehicle's specific main tank design and safety considerations. Never modify your main tank yourself unless using a kit specifically engineered for your vehicle and approved auxiliary tank. Tank installation must be rock-solid using manufacturer-supplied brackets and hardware to withstand impacts and prevent shifting. Thoroughly pressure test the entire system after installation (checking tank, lines, pump, connections) for leaks using appropriate safe methods before adding fuel.
Installation Process (General Overview)
A successful installation requires planning and careful execution. Consult the specific instructions provided with your chosen auxiliary tank kit. Ensure you have all the tools required beforehand. Choose the location carefully, double-checking fitment and ensuring proper clearance. Pre-fit all components loosely before making permanent commitments. Secure the auxiliary tank firmly using all provided hardware and brackets. Mount the transfer pump in its designated location, ensuring proper orientation (often specified). Install the filler neck securely. If required, carefully drill necessary holes (use step bits for clean holes in metal) following kit instructions, using grommets to protect fuel lines and wiring. Connect fuel lines using correct fittings. Route them meticulously away from hazards and secure them frequently. Ensure the vent system is correctly connected. Run wiring harnesses according to the diagram. Connect the power lead (fused within 18 inches of the battery or auxiliary power source), ground connections, relay, and dash switch precisely. Once installed, perform a thorough pressure test. Visually inspect every connection point and along the entire length of fuel lines. Repair any leaks found. Add a small amount of fuel to the auxiliary tank and test the pump operation and transfer. Verify correct function of overfill protection if equipped. Test the dash switch. Carefully clean up any spilled fuel immediately.
Usage Tips and Ongoing Maintenance
Use the auxiliary tank regularly to prevent fuel from becoming excessively stale. Turn on the pump to transfer fuel before the main tank level becomes critically low. This avoids running the main tank's in-tank pump dry, which can cause damage and stall the vehicle. Transfer fuel gradually as needed rather than running the transfer pump constantly for long periods. Keep an eye on the auxiliary tank level using the provided gauge or markings. Periodically inspect the entire system visually for leaks, chafed lines, loose connections, or corrosion (check tank mounts and straps as well). Check the electrical connections periodically for tightness and signs of corrosion. Replace the auxiliary tank fuel filter (if equipped) according to manufacturer intervals. Ensure all tank vents remain clear and unblocked. Maintain the condition of the auxiliary tank filler cap seal. Avoid contamination when refueling. Adhere to all safety precautions when handling and refueling, especially in dusty or hazardous environments.
Long-Term Advantages and Peace of Mind
Investing in a high-quality auxiliary fuel tank system with a pump to the main tank delivers substantial, long-term benefits. Maximizing driving range translates directly into reduced travel time and increased productivity or leisure enjoyment. The ability to choose when and where to refuel the auxiliary tank provides flexibility, potentially saving money on fuel by avoiding higher-priced remote stations or taking advantage of better deals. Knowing you have a substantial, safe, and reliable reserve fuel supply significantly reduces travel anxiety, especially on unfamiliar or isolated routes. Whether used for work demanding extended shifts without refueling stops, for adventurous travel far off the beaten path, or simply for the freedom to drive longer distances with fewer interruptions, this upgrade fundamentally enhances the utility and capability of your vehicle.
By carefully selecting the right components for your vehicle and needs, prioritizing safety during installation, and performing routine maintenance, an auxiliary fuel tank with pump to main tank is a remarkably practical solution for anyone needing to extend their driving range reliably and safely. The upfront effort pays dividends in convenience, efficiency, and preparedness for countless miles ahead.