Transfer Flow, Inc. - Over 30 Years of Expert Engineering

Need more capacity? OEM and aftermarket fuel tanks that keep you moving.


Toolbox and Fuel Tank Combos. All-in-one auxillary fuel tank and storage box


Transfer Flow in-bed auxiliary tanks offer maximum fuel capacity at an affordable price and are available in several aluminized steel and diamond plate aluminum configurations for most Ford, Dodge, and GM pickups. Exclusive design features and optional kits allow some tanks to be used in conjunction with other popular cargo accessories such as Pace-Edwards™, Truck Covers USA™, and Roll-N-Lock™ retractable truck bed covers, as well as most standard tonneaus and camper shells. Transfer Flow fuel tanks are fully baffled to minimize sloshing and come complete with all necessary installation components and detailed instructions. With our patented and industry leading TRAX-II™ fuel system management, the transfer process is entirely automatic and 100% worry free.

Configurations & Features

37 Gallon Roll-Top Fuel Tank

Our 37 gallon in-bed fuel tank fits short and long bed pickups. It's designed to fit under Pace-Edwards™, Truck Covers USA™ and Roll-N-Lock™ retractable bed covers. The tank is available in 14 gauge aluminized steel with black powder coat finish only.

50 Gallon Low Profile Fuel Tank

The height of this tank allows it to fit under a tonneau cover. This tank fits short bed and long bed pickups, and is available in either 14 gauge aluminized steel with black powder coat finish, or bright polished aluminum diamond plate.

75 Gallon Space Saving Fuel Tank

Our 75 gallon in-bed fuel tank is just 18" deep and delivers a significant increase in fuel capacity while maintaining maximum cargo space. The tank fits short and long bed pickups is available in 14 gauge aluminized steel with black powder coat finish only.

98 Gallon High Capacity Fuel Tank

The 98 gallon fuel tank is our largest auxiliary and fits long bed pickups only. Choose from either 14 gauge aluminized steel with black powder coat finish, or bright polished aluminum diamond plate.

Features and Benefits

  • In-bed auxiliary fuel tank systems operate with Transfer Flow's patented TRAX-II® operating system
  • TRAX-II® dash-mounted LCD displays fuel levels of stock fuel tank, auxiliary fuel tank, and total gallons on board vehicle
  • TRAX-II® transfers fuel automatically from the in-bed fuel tank to the stock fuel tank
  • Available in 37, 50, 75 and 98 gallon fuel tanks
  • Available for gas and diesel Dodge, Ford and GM pickups
  • Fuel tanks made from sturdy 14-gauge aluminized steel or aluminum diamond plate
  • 14-gauge aluminized steel fuel tanks are powder coated black and are available in 37, 50, 75 and 98 gallon tanks
  • Aluminum diamond plate fuel tanks are 1/8" thick and are available in 50 and 98 gallon tanks
  • 37 gallon fuel tank fits under a Pace-Edwards®, Roll-N-Lock®, and Truck Covers USA® retractable bed covers
  • 50 gallon fuel tank fits under a standard tonneau cover
  • Fuel tanks are baffled to reduce fuel sloshing
  • Comes complete with all parts needed for installation, including dash-mounted LCD display, wire harness, 6 psi fuel pump, roll-over valve, in-tank sending unit, in-line fuel filter, fuel cap and mounting hardware (some vehicles may require fillneck adapter kit)
  • Optional Camper Shell Fillneck Kit allows you to fill fuel tank through your camper shell
  • New spray-on coating available (same material as a spray-on bedliner)
  • Comes with Transfer Flow's 3 year/60,000 mile limited warranty
  • Won't interfere with standard 5th wheel hitch
  • Over 300 authorized fuel tank installers in the US and Canada
  • Proudly made in the USA!


We make our Liquid Transfer Tank series in two diffrent styles to create the right product for your needs

  • Aluminum UWS aluminum truck boxes are designed and manufactured for the professional workman or truck owner looking for a tough, well-built toolbox.
    • ProGrade Steel Backed by a limited lifetime warranty, UWS ProGrade boxes are built to withstand the most rugged, heavy-duty conditions space.