Combo Fuel/Tool Boxes

Buyer’s Guide: Tool/Fuel Combo Boxes


Dual-purpose combo refuel-tank/toolboxes maximize bed space and increase utility value in the field


By Steve Campbell

Work truck bed space is always at a premium, and lockable storage is even more valuable. Having quick access to spare fuel is also nice, especially for smaller companies with just a couple pieces of equipment in the field.pp_combo boxes and tanks_01

So, contractors who need to carry spare fuel for construction and landscaping equipment, along with tools, oil, straps, chains and other small items used around a jobsite, find a bed-mounted combination toolbox/fuel tank an extremely attractive addition to their rolling office.

Today’s selection of bed-mounted combo tanks provide double, triple or even quadruple the capacity of the truck’s fuel tank, with capacities ranging from 30 to 100 gallons.

Those extra gallons of fuel in the bed of your pickup can provide a full day’s worth of work out of smaller equipment without wasted downtime making a fuel run.

Choosing which tool-and-fuel combo box is best for your needs is as much a matter of personal preference as it is design. Bed-mounted fuel tanks come in two distinct types: auxiliary and transfer tanks. Tanks are built task-specific; one should never be set up to do the job of the other.

The most common are transfer tanks, which require an external pump, hose and nozzle to transfer fuel from the bed-mounted tank to secondary equipment or to “refuel” the truck itself.

These tanks are generally restricted to noncombustible liquids – meaning no gasoline – and are most often used for diesel fuel. They can also be used to carry liquid fertilizers, nonpotable water and the like.

The second type of bed-mounted fuel tank available with toolbox combinations is the auxiliary tank. These tanks are generally plumbed into the vehicle’s factory fuel system, essentially acting as a second tank for the vehicle. Some versions allow the option of an external pump, hose and nozzle for refueling of off-board equipment.

Most auxiliary tanks include a dash-mounted switch that allows the operator to select which tank the truck draws fuel from, and the factory in-dash fuel gauge monitors the tank that is currently in use.

What you don’t want to do is jerry-rig a transfer tank so it acts as an auxiliary fuel tank. Doing so creates your own business insurance and liability issues along with warranty issues with most fuel tank manufacturers.

“We know customers do this, but if they do this with one of our tanks, it voids the warranty,” warns Chris Schiphof, vice president of sales at Tradesman Truck Accessories, a builder of fuel transfer tanks and toolboxes since the early 1970s.

“We can’t be liable for any engines, and that is why we stress the customer to buy an auxiliary tank if that is what they need.”


Tool/fuel combos are available in aluminum, steel or aluminized-steel versions. Aluminum is lighter and won’t rust; steel is generally heavier and stronger. Diamond-plate aluminum has become an extremely popular choice because of its strength-to-weight ratio and because the material retains its appearance longer than other types.Tank-Box Low Res-007

Some tool/fuel combos are designed as a single unit, with the tank built as an integral part of the whole. Other units are built using an “L”-shaped fuel tank with a rectangular toolbox either welded to or sitting atop the foot of the “L.”

Standard fuel capacities for integrated toolbox/fuel tank combinations range from 30 to 60 gallons, while L-tanks typically provide 50 to 100 gallons. Both types serve the same purpose but the integrated units offer a seamless appearance, while the two-piece allows the option of changing the tool box or fuel tank at will.

Toolboxes integrated with a fuel tank are reasonably roomy, with typical capacities ranging from about 5 to 10 cubic feet of storage. If maximum cargo capacity is a goal, look to the L-tank design because those toolboxes are standard capacity.

A variety of combination designs allow for the toolbox section to open with a single lid, double lids (also called gullwing lids) and units to accommodate fifth-wheel and gooseneck trailer hitches. Some toolbox/fuel tank manufacturers offer custom units designed and built to meet unique bed or tool configurations.

Some refuel designs place the filler neck and pump within the toolbox so that they are protected when the box is locked; other designs have the filler and pump outside the box for fulltime access.


Another item to look for when buying a tank of either type is it being designed with internal baffles, which are used to prevent fuel from sloshing excessively while cornering, preventing any adverse affect on your pickup’s handling. This is especially helpful in tanks carrying more than 50 gallons.Tank-Box Low Res-001

The fuel pickup location is also important: If the pickup point is not from the top of the tank, ensure that a lower point is fully protected from being accidentally dislodged, allowing the fuel to leak and creating environmental and safety hazards.

It’s also good to have fuel gauge in either style tank to provide accurate information as to how much fuel remains.

And before you order that toolbox/tank combo it’s prudent to double-check the measurement of the bed box carefully to make sure that the tank you are ordering will fit without interference – or interfere with the gooseneck mounting location.

Selecting a tool/fuel combo box is a good business investment. Efficient use of a pickup is always a benefit to a professional operation, and the ability to transport sufficient fuel and tools in the bed adds value to these two-in-one systems.