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40 Gallon Auxiliary Fuel Tanks

Browse our selection of 40 gallon diesel auxiliary fuel tanks. Auxiliary fuel tanks will connect to your truck's factory fuel tank if you have a diesel powered truck. We offer aluminum or steel auxiliary fuel tanks.

Compare our 40 gallon auxiliary fuel tanks below or check all auxiliary tanks.

  • ATI AUX30R auxiliary fuel tank
    Save up to 15% Save %
    $675.00 - $776.47
    $675.00 - $776.47
    $675.00
    $573.75 - $660.00
    $573.75 - $660.00
    $573.75

    ATI Rectangular Diesel Aluminum Auxiliary Tank

    Aluminum Tank Industries

    Aluminum Tank Industries rectangle aluminum auxiliary fuel tank is available in sizes that range from 30 gallons to 55 gallons.  These light weigh...

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    $675.00 - $776.47
    $675.00 - $776.47
    $675.00
    $573.75 - $660.00
    $573.75 - $660.00
    $573.75
    Save up to 15% Save %
  • Fuelbox Under Tonneau Cover Fuel Tank Toolbox
    Save up to 12% Save %
    $2,159.00 - $2,299.00
    $2,159.00 - $2,299.00
    $2,159.00
    $1,900.00 - $2,135.00
    $1,900.00 - $2,135.00
    $1,900.00

    The Fuelbox Under Tonneau Fuel Tank Toolbox Combo

    The Fuelbox

    The Fuelbox Under Tonneau is a low profile fuel tank toolbox combo.  This fuel tank toolbox combo is designed to work with most tonneau covers. Th...

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    $2,159.00 - $2,299.00
    $2,159.00 - $2,299.00
    $2,159.00
    $1,900.00 - $2,135.00
    $1,900.00 - $2,135.00
    $1,900.00
    Save up to 12% Save %
  • ATTA Diesel Auxiliary Roll-Top Bedcover Tank 45 gallon
    Save up to 9% Save %
    $1,161.00 - $1,404.00
    $1,161.00 - $1,404.00
    $1,161.00
    $1,055.00 - $1,276.00
    $1,055.00 - $1,276.00
    $1,055.00

    ATTA Diesel Auxiliary Roll-Top Bedcover Tank

    ATTA

    The aluminum ATTA Auxiliary Roll-Top Bedcover Tank is designed to be in conjunction with a roll-top bed cover. The aluminum auxiliary diesel tank ...

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    $1,161.00 - $1,404.00
    $1,161.00 - $1,404.00
    $1,161.00
    $1,055.00 - $1,276.00
    $1,055.00 - $1,276.00
    $1,055.00
    Save up to 9% Save %
  • Transfer Flow Under Tonneau Cover Auxiliary Tank
    $1,745.26 - $1,870.62
    $1,745.26 - $1,870.62
    $1,745.26 - $1,870.62
    $1,745.26

    Transfer Flow Low Profile Under Tonneau Auxiliary Fuel Tank

    Transfer Flow

    The low profile Transfer Flow auxiliary fuel tank is designed to fit under tonneau covers.  Choose from 40 or 50 gallon sizes. Either option offers...

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    $1,745.26 - $1,870.62
    $1,745.26 - $1,870.62
    $1,745.26 - $1,870.62
    $1,745.26
  • The Fuelbox FT47 closeup
    Save up to 15% Save %
    $1,747.00 - $2,029.00
    $1,747.00 - $2,029.00
    $1,747.00
    $1,485.00 - $1,725.00
    $1,485.00 - $1,725.00
    $1,485.00

    The Fuelbox Auxiliary Fuel Transfer Tank

    The Fuelbox

    The Fuelbox Auxiliary Fuel Transfer Tank is an in bed diesel fuel tank. Choose whether you want to use this fuel tank as a transfer tank or an auxi...

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    $1,747.00 - $2,029.00
    $1,747.00 - $2,029.00
    $1,747.00
    $1,485.00 - $1,725.00
    $1,485.00 - $1,725.00
    $1,485.00
    Save up to 15% Save %
  • ATTA Below Bed Rail Diesel Auxiliary Tank 45 gallons
    Save up to 9% Save %
    $949.00 - $1,372.00
    $949.00 - $1,372.00
    $949.00
    $863.00 - $1,247.00
    $863.00 - $1,247.00
    $863.00

    ATTA Low Profile Below Bed Rail Diesel Auxiliary Tank

    ATTA

    ATTA Low Profile Below Bed Rail rectangular tanks are designed to be used with a hard or soft bed cover. The highest portion of the tank will be b...

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    $949.00 - $1,372.00
    $949.00 - $1,372.00
    $949.00
    $863.00 - $1,247.00
    $863.00 - $1,247.00
    $863.00
    Save up to 9% Save %
  • Save up to 9% Save %
    $904.00 - $1,459.00
    $904.00 - $1,459.00
    $904.00
    $822.00 - $1,326.00
    $822.00 - $1,326.00
    $822.00

    ATTA Rectangular Diesel Auxiliary Fuel Tank

    ATTA

    ATTA rectangular diesel auxiliary fuel tanks are designed with .125 aluminum gage and are available in sizes that range from 40 gallons to 110 gall...

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    $904.00 - $1,459.00
    $904.00 - $1,459.00
    $904.00
    $822.00 - $1,326.00
    $822.00 - $1,326.00
    $822.00
    Save up to 9% Save %