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HAULK DEPOT

Auxiliary Fuel Tank – 40 Gallon Aluminum – DOT Approved | RDS
SKU: AFT-40G
$900.00 USD $900.00 USD $1,035.00 USD
Sale 13.04% $135.00 USD (13.04%)
Shipping calculated at checkout.
Out of stock
Description

This 40-gallon aluminum auxiliary fuel tank by RDS is built for durability, compliance, and extended range. Designed for diesel use in fifth-wheel and long-haul truck setups, this DOT-approved tank offers an excellent solution for increasing fuel capacity. It features a front corner fill, internal baffles, and full integration support with return, drain, and withdraw fittings.

Detailed Information:
Manufacturer RDS Manufacturing
Capacity 40 Gallons (Approx. 95% Usable)
Material Aluminum
Mounting Brackets Included
Fill Location Front Corner
DOT Compliance Yes
Fitting:

Designed for fifth-wheel and other long-range diesel applications. Compatible with RDS Diesel Install Kits (sold separately). Includes withdraw, return, and drain ports for seamless fuel system integration. A blank plate is included for optional fuel pump or sending unit installation.

Features:
  • Extended Range: Adds 40 gallons of additional fuel capacity to your vehicle.
  • Built-In Baffles: Internal baffles reduce sloshing, improving safety and stability.
  • Leak-Tested: Pressure tested to ensure long-term reliability and fuel containment.
  • Corrosion-Resistant: Constructed from lightweight, rust-resistant aluminum.
  • Versatile Compatibility: Can be used with diesel, water, biofuel, and other approved liquids.
  • Overfill Protection: Filler neck design helps prevent spillage during refueling.
Interchangeable Part Numbers:
  • RDS-70387
Product Overview:

The RDS 40-Gallon Aluminum Auxiliary Fuel Tank is a rugged, DOT-compliant solution for expanding your fuel range on long trips. Ideal for heavy-duty and fifth-wheel setups, this notched rectangular tank features all necessary fittings for easy system connection and comes ready for installation with mounting hardware. A smart choice for truck owners, fleets, and anyone needing extended travel capacity.

We want you to be completely satisfied with your purchase. That’s why we offer a hassle-free return policy within 30 days of delivery*. If your item is unused, in original packaging, and eligible for return, you can send it back for a refund or exchange.

*Some exclusions may apply

Some of our products are backed by a 1-year limited manufacturer warranty covering defects in materials and workmanship under normal use. If you experience any issues during this period, we’ll work with you to repair, replace, or resolve it according to warranty terms.*

*Proof of purchase required

Need it fast? We’ve got you covered. Orders confirmed before 3 PM Eastern Standard Time (Monday–Friday) are processed and shipped out the same business day. Orders placed after the cutoff will ship the next business day.
Auxiliary Fuel Tank – 40 Gallon Aluminum – DOT Approved | RDS

Customer Reviews

Based on 12 reviews
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(10)
17%
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M
Moore Cosely
Well-Built and Reliable

The build quality is excellent. Pressure-tested and leak-free as promised. This tank is a solid investment for anyone who travels a lot for work.

E
Ephrayim Easen
Great for My Fifth-Wheel Setup

This 40-gallon RDS tank was a perfect addition to my long-haul rig. The front-corner fill is super convenient, and the included fittings made the install pretty straightforward. No leaks so far, and the baffles really do help with sloshing.

L
Lazarus D'eathe
Heavy-Duty Tank for a Heavy-Duty Job

This is a serious piece of equipment. I've been running it for a few months now, and it's held up great. No dents, no leaks, and the front fill is a major time-saver.

T
Tybalt Manolov
Exactly What I Needed

I needed a reliable auxiliary tank for my fleet vehicle. This RDS tank fit the bill perfectly. The materials are top-notch and the DOT approval is essential for my business.

T
Tomasz Kowalski
Great Quality and Easy Integration

The internal baffles are a big plus. It's nice not to feel the fuel sloshing around. Installation was straightforward with the separate kit. This tank is a great value.

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