Best Diesel Generator External Fuel Tank Options for Safe Refueling
Direct answer: External fuel tanks designed for diesel generators offer extended run times and easier refueling, especially for portable and open-frame units. This guide highlights five practical options, each best for different generator setups and user needs. Readers will learn which tank suits their generator size, mounting space, and fueling preferences. The top picks below are chosen for compatibility, capacity, and clear safety considerations.
The following quick-reference table lists key attributes to compare at a glance.
| Product | Best For | Fuel Capacity | Notes |
|---|---|---|---|
| RDS Aluminum Auxiliary Fuel Tank | Outdoor installations, rugged exterior spaces | 20 gallons | Vent-cap and dual withdrawal tubes; not for gasoline |
| Bergs System HND1.2000IS | Single system with hose integration | Not specified in listing | Tank hose included |
| POWER PRODUCTS Universal 4 Gallon Fuel Tank | Small open-frame diesel gensets | 4 gallons | ABS, chrome finish, universal fit |
| JJing Universal 7 Gallon Tank | Mid-size generators | 7 gallons | No vent valve; check dimensions carefully |
| EVIL ENERGY 19 Gallon Fuel Cell | Versatile fuel compatibility and level sensing | 19 gallons | Includes level sender and anti-slosh foam |
RDS Aluminum Auxiliary Fuel Tank – 20-Gallon
Product overview: This rectangular, smooth-aluminum tank is designed for exterior areas, with a vented fill cap and dual withdrawal tubes. The second tube can be used for diesel as a fuel return line. Best for outdoor, weather-exposed installations where a compact, rugged tank is needed.
Who it’s best for and why selected: Ideal for users with outdoor generator setups that require a durable, vented fuel supply. The dual withdrawal tubes simplify routing for diesel-specific refueling or return lines, making it convenient for larger portable gensets used off-grid or job sites.
Limitations: It is not intended for gasoline use. The description emphasizes outdoor durability but does not specify mounting hardware or a built-in gauge, so verify your install needs before purchase.
Bergs System HND1.2000IS Bergs Single System
Product overview: The Bergs HND1.2000IS is a single system that includes a tank hose, designed to integrate with Bergs’ system components. This option suits users who want a compact, ready-to-connect system for straightforward fueling between a generator and a portable tank.
Who it’s best for and why selected: Choose this if you want an all-in-one feel with included hose for a clean, simple installation on compatible Bergs setups or when you prefer a minimized number of separate parts.
Limitations: The listing notes a hose-inclusive package but does not specify overall capacity or tank dimensions, so confirm compatibility with your generator and mounting space before purchasing.
POWER PRODUCTS Universal 4 Gallon Diesel Tank
Product overview: This ABS-built, chrome-finished fuel tank fits most open-frame 5-7KW diesel generators. Its dimensions are 18 inches long, 13 inches wide, and 5-1/4 inches high, offering a compact option for smaller gensets that still need a dedicated diesel reservoir.
Who it’s best for and why selected: Best for small to mid-size open-frame generators that require a lightweight, universal tank with easy mounting and a clean look. The compact footprint helps save space in tight setups.
Limitations: The listing provides specific dimensions but does not detail venting or fuel gauge features, so verify venting needs and gauge preferences for your unit.
JJing Universal 7 Gallon Tank for Generators
Product overview: This 7-gallon tank has mounting dimensions of approximately 23.25″ long, 16.1″ wide, and 6.1″ tall. It notes that the tank does not include a vent valve and warns buyers to check sizes carefully before ordering.
Who it’s best for and why selected: Suited for mid-size generators where the user can tolerate a non-vented tank and wants a larger capacity than 4 or 5 gallons. The dimensional guidance helps avoid fit issues.
Limitations: The lack of a vent valve means it is not suitable where venting is required for safe fuel transfer or to prevent vapor buildup. The note about exact capacity tells buyers to expect slightly less than the advertised 7 gallons.
EVIL ENERGY 19 Gallon Fuel Cell
Product overview: A 19-gallon aluminum fuel cell with a built-in 3–90 ohm level sensor and internal anti-slosh foam. It features robust external dimensions and dual-use compatibility for fuel types with appropriate lines.
Who it’s best for and why selected: Best for users needing large capacity with integrated level sensing for monitoring diesel levels in real-time. The anti-slosh foam helps stabilize fuel flow on transport or bumpy sites.
Limitations: Not all fuels may be suitable depending on the connected hoses and lines; confirm compatibility with your generator’s fuel system and ensure the sensor wiring matches your setup.
JJing Universal 5 Gallon Tank for Generators
Product overview: This 5-gallon tank is designed for various Honda, Predator, Champion, Duromax, Wen, and other generators. It includes mounting dimensions of 20″ length, 13.19″ width, and 5.9″ height, and notes that it does not include a vent valve.
Who it’s best for and why selected: Suitable for users with mid-size open-frame generators who want a compact, universal 5-gallon option. The listing emphasizes careful dimension checking to avoid incompatibilities.
Limitations: Like other non-vented tanks, this option may not meet venting requirements for all setups. The stated capacity may be slightly under 5 gallons in practice, so plan for minor variance.
Buying Guide: External Diesel Tank Essentials
What to consider when selecting an external fuel tank for a diesel generator?
- Capacity vs. run time: Larger tanks extend runtime but require more space. Balance fuel needs with available mounting area.
- Ventilation and fuel venting: If you operate indoors or in enclosed spaces, a vented tank is often preferred for safety and vapor mitigation. If a vent valve is not included, ensure your setup complies with local safety standards.
- Material and durability: Aluminum and high-density polyethylene offer different advantages. Aluminum is lightweight and corrosion-resistant; polymer tanks resist impact and weather but may require UV protection.
- Mounting and space: Measure space where the tank will be placed and confirm mounting compatibility with your generator frame or trailer.
- Fuel compatibility: Confirm whether the tank is intended for diesel use and whether you may need a return or bypass line for efficient operation.
- Gauges and sensors: Built-in fuel gauges or level sensors help monitor fuel levels, reducing the risk of unexpected outages.
- Accessories and fittings: Hose assemblies, vent caps, and grommets vary by model. Ensure included components meet your installation needs.
Frequently Asked Questions
- Do external diesel tanks require venting? Yes, many tanks use vented caps to prevent pressure buildup. If a model does not have a vent, verify your installation meets safety requirements.
- What capacity should I choose for my generator? Choose capacity based on generator runtime needs and available mounting space. Higher capacity means longer runtime but larger footprint.
- Can I use these tanks with gas-powered generators? Some tanks are specified for diesel and may not be suitable for gasoline. Always follow the manufacturer’s guidance.
- Will a fuel gauge be included? Some models include a built-in gauge or level sensor. If monitoring is important, select a model with gauge features.
- Is portability important? For frequent transport, consider a tank with a secure lid, theft protection features, and a compact shape.
- Do these tanks come with installation hardware? Some listings include hoses or fittings; others require additional components. Check what’s included before purchase.