A transfer tank carries fuel to the job instead of sending the crew back for it. The decisions are shape, capacity and pump, and one legal question that catches people out.
Which Shape Suits Your Bed?
Shape decides how much bed floor you keep. L-shape tanks wrap over the wheel wells and down the floor, giving the most capacity for the length. Rectangle tanks sit straight across the front of the bed and are simplest to strap down. Column tanks stand tall and narrow against the bulkhead and leave the most floor free.
If you also need secure storage, a combo unit puts a tool box on top of the tank and uses one footprint for both. That is usually cheaper than buying a tank and a box separately, and it stops the two competing for the same space.
Capacity and Weight
Diesel weighs roughly 7 lb per gallon. A full 100 gallon tank is about 700 lb of fuel before you count the tank, and that sits high and forward in the bed.
- 50 gallons: topping off equipment on site.
- 75 to 90 gallons: a crew running machines through a full day.
- 100 to 110 gallons: fuelling a fleet without a return trip.
Check your payload rating before sizing up. It is easy to specify a tank that puts a half-ton over its limit when full.
Can You Carry Gasoline?
Generally no. Most transfer tanks are rated for diesel only. Gasoline is regulated far more tightly because of its vapour, and carrying it in a tank not rated for it is both unsafe and usually not permitted. If gasoline is what you need to move, look specifically for a tank certified for it rather than assuming a diesel tank will do.
Pumps and Plumbing
A tank without a pump is a heavy container. Twelve volt pumps run off the truck battery and move roughly 15 gallons per minute, which is fine for equipment fills. Some tanks ship with a pump and some are sold bare, so check before ordering.
Run the wiring on a fused circuit sized for the pump, and keep the nozzle secured when moving. A hose swinging loose in the bed will find something to catch on.
Mount It Properly
A full tank is heavy enough to shift under braking, and a shifting 700 lb load changes how the truck stops. Use the tank's own brackets or a bolt-down kit rather than relying on friction and a strap. Anything that can move should be secured to the bed, not to another loose item.
What to Do Next
Pick the shape from your bed layout, the capacity from your payload, then confirm the pump. See transfer tanks, and truck tool boxes if you would rather keep fuel and storage separate.