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Questions? Call or Text our US based team: 800-964-5341
Questions? Call or Text our US based team: 800-964-5341

ATI Rectangular Diesel Aluminum Auxiliary Tank


Questions? Call our US Based team: 1-800-964-5341 (9am-9pm; 7 days a week)

Original price $675.00 - Original price $776.47
Original price $675.00
$573.75 - $660.00
Current price $573.75

1 to 2 week estimated lead time

We have limited stock for some products which can ship in 3 to 4 days.

Please call or use the Request Custom Quote form (below) for the most current lead times.

Custom Tank Sizes Available: Call or Use Custom Quote form below.

Request Volume Ship Quote or Custom Tank Size

Aluminum Tank Industries rectangle aluminum auxiliary fuel tank is available in sizes that range from 30 gallons to 55 gallons.  These light weight aluminum fuel tanks offer a variety of sizes and shapes that easily fit in your bed space.

ATI auxiliary tanks are used to increase driving range and fuel capacity by as much as 80 gallons by connecting directly into your factory fuel tank through the factory filler neck. 

All ATI auxiliary tanks come standard with a 3/8″npt outlet, vent with rollover protection, automotive style fuel cap, and fully welded baffles to reduce slosh and add strength.

These tanks are constructed from rugged diamond plate aluminum and are all available with a black or white powder coated finish. Custom tanks are available upon request. 

ATI FUEL SHOTZ (Available as Optional Accessory on Product Page)

These tanks are designed for use with the ATI Fuel Shotz diesel install kits. The diesel FUEL SHOTZ installation kit can be installed in less than an hour.  The unique system connects the auxiliary tank to the factory tank vis the factory filler. 

This will keep your factory tank completely full until the auxiliary tank is empty. You will know your auxiliary tank is empty when your factory fuel gauge moves off the full mark. 

The FUEL SHOTZ system installs quickly and easily. No wires or switches to install.  The system has rollover protection on the tank and on the factory fill neck adaptor.  Detailed instructions are supplied with the FUEL SHOTZ installation kit.

Diesel Auxiliary Tank Sizes

ATI rectangular auxiliary tanks less than 50 gallons ship by UPS:

  • AUX30R: 30 Gallon - 48.5"L x 19"W x 9"H.
  • AUX41R: 41 Gallon - 48.5"L x 11"W x 19"H.
  • AUX42R: 42 Gallon - 48.5"L x 19"W x 12"H.
  • AUX43R: 43 Gallon* - 51"L x 12"W x 16.5"H.
  • AUX46R: 46 Gallon - 57"L x 12"W by 16.5"H.

See pictures of each tank size below:

*43 gallon size is notched with a bottom tank length of 51 inches and a top length of 58 inches.

AUX30R Under Toolbox Auxiliary Tank

ATI AUX30R auxiliary fuel tank

AUX30R: 30 gallon* - 48.5"L x 19"W x 9"H / fits short beds with tab modification

This tanks low 9 inch height is designed to fit underneath a truck bed mounted toolbox. 

If you have a short bed truck, you need to request a modification to move the side mounting tabs to the front and back of the tank (the two 1.5" side mounting tabs add 3 inches to the tank length).

*The AUX30R tank includes a 3.5 inch diagonal fill neck.  All other tanks have a 2.5 inch top mounted fill neck.

AUX41R Short Bed Auxiliary Tank

ATI AUX41R auxiliary fuel tank

AUX41R: 41 gallon - 48.5"L x 11"W x 19"H / fits short beds

The AUX41R will fit most short bed trucks that have 11 inches or greater space between the cab and the start of the wheel wells.

AUX42R Flat Auxiliary Tank

ATI AUX42R auxiliary fuel tank

AUX42R: 42 gallon - 48.5"L x 19"W x 12"H / fits short beds with tab modification

If you have a short bed truck, you need to request a modification to move the side mounting tabs to the front and back of the tank to allow the tank to pass between the wheel wells.

AUX43R Slim Auxiliary Tank

ATI AUX43R auxiliary fuel tank

AUX43R: 43 gallon* - 51"L x 12"W x 16.5"H / fits short beds

The AUX43R tank will fit short bed trucks with 12 inches or greater space between the cab and the start of the wheel wells. 

If you have less than 12 inches of space, you can request to move the side mounting tabs to the front and back of the tank so the 51 inch notched tank length can pass between the wheel well.

*AUX43R has a notched bottom length of 51 inches and a top length of 58 inches.

AUX46R Narrow Auxiliary Tank

ATI AUX46R auxiliary fuel tank

AUX46R: 46 gallon - 57"L x 12"W x 16.5"H / fits short beds

The AUX46R will fit short beds with 12 inches or greater space between the cab and the wheel wells.

Note: mounting tabs add 1.5 inches on each side of the tanks listed above.  The two mounting tabs on each side increase the tank length by 3 inches.

If you have a short bed truck you may need to add a modification to move the mounting tabs from the sides to the front & back so the tank can pass through the wheel well.  Please call or contact us if you have a short bed truck to confirm.

The fill neck adds 2.5 inches of height to the top of the tank and has a 2.5 inch diameter.  The fill neck is also located halfway between the center of the tank and the left edge of the tank.

All ATI diesel auxiliary tanks come standard with the following:

  • Meets DOT requirements for diesel auxiliary.
  • Custom auxiliary install kit included with tank.
  • All aluminum fuel tank construction.
  • Quick easy installation.
  • Tanks are baffled to reduce movement of contents.
  • No wires or switches to install.
  • Rollover protection.
  • Automotive style fill cap.
  • Hold down brackets.
  • Pressure and leak detection test.
  • Clean and free of debris inside and outside of the tank.
  • 1 year limited warranty.

ATI Auxiliary Tank Fuel Shotz Kit Installation Guide

Other Fuel Tank Options:

Can I use your refueling tanks for gasoline legally?

Yes, we manufacture our aluminum refueling tanks to meet and exceed the requirements for gasoline, kerosene, methanol, and diesel. In fact, many government agencies are currently using our aluminum refueling tanks.

Can I pump from your refueling tank without removing it from the bed of my truck?

Yes it is legal to pump from our tanks while still in the bed of a truck whether the tank is being used for private, state, or commercial use.

Do all of your fuel tanks have baffles inside?

Yes, all of our tanks are baffled to provide strength and support and to reduce fuel sloshing.

How Does your Fuel Shotz diesel fuel system work?

This unique system connects the auxiliary fuel tank to the factory fuel tank via the factory filler. The auxiliary fuel tank keeps the factory fuel tank full until the auxiliary fuel tank is empty.

Are the inside of your auxiliary and refueling tanks free of debris?

Yes, all of our auxiliary and refueling tanks will be clean and free of debris on the inside and outside before leaving the factory.

Are your tanks tested for leaks?

Yes, all of our tanks are visually inspected and pressure tested for leaks. We also use a video inspection system to check for penetration on the inside of the tank.

What is the aluminum fitting on top of my aluminum refueling tank?

The aluminum fitting on top of your refueling tank is a fuel tank vent with rollover protection.

Do your fuel tanks come with a warranty?

Yes, all of our standard duty tanks and toolboxes come with a one year limited warranty. Our line of Severe Series tanks come with a 5 year limited warranty.

Is Fuel Shotz for diesel fuel systems a legal fuel system?

Yes, the Fuel Shotz system complies with DOT requirements, but you must install it per provided instructions.

Do I need to ground my fuel tanks to the vehicle?

Yes, the tanks need to be grounded at all times. When you install the fuel tank remove the paint from the underside of the truck bed where the tank gets bolted in. That will give a sufficient ground.

How Do I mount my fuel tank?

The fuel tank will come with mounting tabs welded to the tank. You will place the tank in the desired location, check for clearance underneath so you don’t drill into brake lines, fuel lines, etc. Drill and install one bolt, flat washer, lock washer , and nut. Tighten securely. Note: after drilling your mounting hole sand off any paint to bare metal on the bottom side of the truck bed around the bolt hole to ensure a good ground.

Are your fuel tanks lockable?

All of our refueling tanks come with a lockable fuel filler cap. We also offer an optional locking fuel cap for our auxiliary fuel tanks. You can take it a step further and check out our line of fuel safe auxiliary fuel tanks where the fuel filler and fittings are inside a lockable toolbox compartment.

Can I get a black powder coat as an option on my fuel tank?

Yes, we offer powder coat as an option. Our durable powder coat fuel tanks are very popular. Our standard color is gloss black but we also offer textures and many other colors.

Can I get a fuel level gauge?

es, fuel gauges are available as an option for all of our auxiliary fuel tanks and refueling tanks.

Estimated Product Handling: 2 to 3 days

Tank Retailer offers a 30 day return policy for all products. Please see our Return & Refund Policy for more information.

Aluminum Tank Industries, Inc. warrants all products to be free of defects in material or workmanship for a period of 1 year from invoice ship date from our warehouse or purchase date if registered. Severe Series refueling tanks are covered for 5 years. If upon our inspection we deem the item to be defective, Aluminum Tank Industries, Inc. will determine whether to repair or replace the defective item.  It is the customers’ responsibility to ship the item to Aluminum Tank Industries, Inc. No cost for labor, installation, or missing contents will be reimbursed. Damages due to shipping and handling, improper installation, abuse – intentional or accidental, or normal wear and tear are not covered by this warranty. Warranty is void if the tank has been altered. Standard duty tanks are designed for use with transfer pumps up to 30 lbs. Installing a pump over 30 lbs on a standard duty tank will void warranty. A Severe Series tank is required if using a transfer pump over 30 lbs.