ATI Rectangular Diesel Aluminum Auxiliary Tank

Maximize your driving range and minimize fuel stops with the ATI Rectangular Diesel Aluminum Auxiliary Tank — a precision-engineered solution designed for professional fleet operators, owner-operators, and serious diesel truck owners. Constructed from rugged aluminum diamond plate, these auxiliary tanks connect directly to your truck’s factory fuel tank via a simple gravity feed system, keeping your main tank topped off automatically without any pumps, wires, or switches. Whether you’re hauling cross-country, managing a job site, or running a farm operation, the ATI auxiliary tank delivers reliable, extra fuel capacity in a form factor built to withstand the demands of the road.

Key Features

• Gravity-Feed Simplicity: Fuel transfers from the auxiliary tank directly into your factory tank through the filler neck — no electrical connections, switches, or complex plumbing required.
• All-Aluminum Diamond Plate Construction: Lightweight yet exceptionally durable, built to resist corrosion and withstand harsh operating environments.
• Fully Welded Baffles: Reduce fuel slosh during acceleration, braking, and cornering while adding structural rigidity to the tank.
• Rollover Protection: Integrated rollover protection on both the tank vent and the factory fill neck adaptor for added safety.
• Automotive-Style Fuel Cap: Standard equipment for secure, leak-resistant sealing.
• DOT-Compliant Design: Meets DOT requirements for diesel auxiliary fuel tanks.
• Quick Installation: With the optional Fuel Shotz kit, installation can be completed in under an hour using detailed instructions provided.
• Pressure & Leak Detection Tested: Every tank is factory-tested to ensure integrity before shipment.
• 1-Year Limited Warranty: Backed by ATI’s commitment to quality and performance.

Specifications

Available Sizes (all ship UPS — under 50 gallons):

• AUX30R — 30 Gallon – 48.5″L x 19″W x 9″H / Low-profile design fits under truck bed toolbox
• AUX41R — 41 Gallon – 48.5″L x 11″W x 19″H / Designed for short bed trucks
• AUX42R — 42 Gallon – 48.5″L x 19″W x 12″H / Flat profile for short beds
• AUX43R — 43 Gallon* – 51″L x 12″W x 16.5″H / Slim profile for short beds
• AUX46R — 46 Gallon – 57″L x 12″W x 16.5″H / Narrow design for short beds

*AUX43R features a notched design: 51″ bottom length, 58″ top length.

Standard Features (included with every tank):

• 3/8″ NPT outlet
• Vent with rollover protection
• Automotive-style fuel cap
• Fully welded baffles
• Hold-down brackets
• Clean, debris-free interior and exterior
• Pressure and leak detection tested

Fill Neck: The fill neck adds 2.5″ of height to the top of the tank and has a 2.5″ diameter. It is located halfway between the center and the left edge of the tank. Note: The AUX30R includes a 3.5″ diagonal fill neck.

Mounting Note: Standard mounting tabs add 1.5″ on each side of the tank (3″ total added length). For short bed trucks, a modification to move tabs to the front and back is available — please contact us to confirm fitment.

Why Choose ATI Rectangular Diesel Aluminum Auxiliary Tank

ATI auxiliary tanks are purpose-built for diesel truck owners who demand reliability, simplicity, and durability. The gravity-feed Fuel Shotz system eliminates the complexity of electric pumps and wiring, offering a maintenance-free solution that keeps your factory tank full until the auxiliary tank is empty — you’ll know it’s time to refill when your factory gauge moves off the full mark.

Every tank is constructed from all-aluminum diamond plate with fully welded baffles, ensuring it can handle years of heavy use without rust or structural failure. DOT compliance and factory pressure testing give you confidence that your fuel is stored safely and legally. And with sizes ranging from 30 to 46 gallons, there’s an ATI rectangular tank designed to fit your specific truck bed configuration — including options for short beds and under-toolbox installations.

Choose from tank-only or bundled with the Fuel Shotz gravity feed installation kit for a complete, ready-to-install system. Optional accessories including locking fuel caps, tank-mounted gauges, dashboard sending units, and black powder coating allow you to customize your setup for security, convenience, and aesthetics.

Options:

• Auxiliary Tank Only
• Auxiliary Tank + Fuel Shotz Gravity Feed Install Kit

Optional Accessories:

• Tank Mounted Gauge
• Black Powder Coat (gloss or matte)
• Locking Fuel Cap
• Tank Sending Unit & Dashboard Gauge
• Mounting Bolts