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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. The design includes a few changes in the dimensions and lid to make a perfect fit with a tonneau cover.
The Fuelbox Under Tonneau fuel tank toolbox sits below the bed rails and the lid is recessed in so it can fully open with a tonneau cover. It clears most gooseneck and fifth wheel hitches.
*Black powder coat is an optional upgrade; choose Fuelbox protective spray liner for black powder coat.
Note: You must measure your pickup bed with tonneau cover to guarantee clearance.
The Fuelbox is a universal product that can be used as an auxiliary tank, transfer tank, or both.
Tank Sizes (notched lower length):
40 Gallon*: 62 inches long x 23 inches wide x 17.5 inches high
45 Gallon: 62 inches long x 20 inches wide x 17.5 inches high
55 Gallon: 62 inches long x 30 inches wide x 17.5 inches high
All three tanks have a 53 inch lower tank length.
*The 40 gallon size has a bottom tank width of 14 inches. The lower bottom tank width enables the 40 gallon size to fit short bed pickup trucks.
40 Gallon: 62 inches long x 18 inches wide x 5.72 inches deep.
45 Gallon: 62 inches long x 15 inches wide x 5.75 inches deep.
55 Gallon: 62 inches long x 20 inches wide x 8 inches deep.
Note: add 2.25 inches on each side for bottom side mounting tabs.
The Fuelbox can be used in two ways:
As an auxiliary fuel tank for your diesel pickup. Use the Auto Fuel Controller to transfer fuel to your pickup as you drive.
Use the optional transfer pump to transfer fuel from the Fuelbox to other vehicles and equipment. The optional transfer pump mounts inside the tool box so it is secure and out of sight.
The Fuelbox Fuel Tank Toolbox Combo Under Tonneau fits the following vehicles:
6.5 foot short bed: Ford, GM, and RAM
8 foot long bed: Ford, GM, and Ram
6.5 foot short bed: Ford & GM
8 foot long bed: Ford, GM, and Ram
8 foot long bed: Ford, GM, and Ram
Choose Fuelbox Options
Color / Finish
Smooth (comes standard)
Diamond (premium upgrade)
Smooth + Protective Liner
Diamond + Protective Liner
The protective liner is a spray on coat designed to protect your Fuelbox from the elements. The spray on liner changes the Fuelbox color from silver to a smooth charcoal black finish.
Fuel Transfer System
Choose the Auto Fuel Controller or TP13 Transfer Pump or choose both options.
Auto Fuel Controller
Choose the Plug and Play Auto Fuel Controller or the Digital Display Auto Fuel Controller.
The Auto Fuel Controller (AFC) makes the Fuelbox tanks legal in all 50 states for diesel pickups. The AFC system meets or exceeds all DOT & EPA regulations. It also meets the standards required by the VESC-22.
Auto Fuel Controllers (AFC) systems are compatible for all Ford, GM and Dodge diesel pickups. The AFC makes the operation of the auxiliary fuel tanks effortless.
There’s no need to worry about switching between tanks and running out of fuel. Since our system transfers to the stock tank there is NO CUTTING OF FACTORY FUEL LINES and warranty problems that go along with cutting up OEM lines and you will always be running off your factory fuel system.
The AFC computer works in conjunction with the Fuelbox by automatically filling your main tank when it gets low as you drive and shuts off when the main tank gets near full. The AFC monitors the stock OEM fuel tank.
When the stock tank gets near 1⁄4 of a tank it will turn on a transfer pump and transfer fuel from the auxiliary tank to the stock tank. The AFC will shut off the transfer pump when the stock tank is near full or the auxiliary tank is empty.
The AFC can be set for automatic operation or it can be manually turned off from the cab of your truck. In addition there is a manual button, where you can manually transfer fuel for up to 4 minutes.
The Auto Fuel Controller is available in two models: Digital Display Controller or Plug & Play Controller.
Plug & Play Controller: plugs directly into your on-board diagnostic (OBD-II) port on your truck. This makes an easier install and avoids the factory wire harness. The plug and play shows the fuel level percentage in both the vehicle tank and the Fuelbox tank.
Digital Display Controller: is a vehicle specific controller that is programmed for the year and make of the vehicle. The Digital Display controller only shows the fuel level in the Fuelbox tank.
The fuel transfer pump allows you to fill other vehicles and equipment. The transfer pump is a 13 gallon per minute pump with a 12 foot hose and an auto shut-off nozzle.
Transfer Pump Accessories
Filter Kit - Adds filtration to your transfer pump.
Fuel Meter - Logs how many gallons you transfer with the transfer pump.
Fuelbox Optional Accessories
Locking Gas Cap
Tie down bar
Side bed step
*some accessories are not available for all Fuelbox Combo sizes.
The Fuelbox Under Tonneau Fuel Tank Toolbox features:
Fuel tank is constructed of high-quality .125 marine grade aluminum and has a minimum of two interior baffles.
Fuel tank has 90-degree flange reinforced seams, which doubles weld joint thickness for stronger welds.
Toolbox and heavy-duty lid constructed of .100 marine-grade aluminum with an extra-large lid stiffener.
Stainless steel latch and lock assemblies & a continuous hinge that is the full length of the lid.
Toolbox has a unique rain channel with neoprene on the lid that assures a weather-tight seal.
You will also find that the bottom of the toolbox is not the top of the fuel tank, adding extra strength and protection to the fuel tank.
Legal in all 50 states for diesel fuel only & meets or exceeds all DOT & EPA regulations.
No, our tanks are DOT certified & follow EPA regulations for DIESEL FUEL ONLY. The reason for this is all our tanks are vented to the atmosphere. All 1996 and newer gasoline pickup trucks are equipped with a sensor in the tank for emission. If you install our AFC kit on one of these trucks it will set a check engine light and fail the emission test.
How Do I know what kind of Truck Bed I have?
A long bed is approximately 8 ft and a short bed is approximately 6.5ft.
How Difficult is it to Install a Fuelbox?
Anyone with basic mechanical skills can install a Fuelbox or the AFC system. The Fuelbox comes standard with every component needed to install the tank to your truck, excluding the standard hand tools needed for the install. No need to run back and forth to the parts store.
How Long will it take to do an install?
Between 2-4 hours depending on your mechanical skills.
Where Can I have my Fuelbox Installed?
If you aren't comfortable doing the install yourself, you can contact a local auto repair shop for installation.
Will I Void my Vehicle's Warranty if I install one of your fuel tanks?
No, if you install the auxiliary diesel fuel tank per the instructions and use the components that come with the installation kit, it will not void your factory warranty.
Will My Diesel Pickup Pass an Emission Test?
Yes, our tanks do not alter the stock fuel delivery system. By not altering this system the Fuelbox fuel tanks are approved for use without exemption by the California Air Resources Board (CARB).
Do Your Tanks Come with a Warranty?
Aluminum Tanks – 3 Year Warranty, on all component parts, and against defects in material & workmanship.
AFC Products – 1 Year Warranty Fuel Pump, 1 Year Warranty limited to Warranty provisions of Original Manufacturer.
Transfer Pump – 2 Year Warranty limited to Warranty provisions of Original Manufacturer.
Are your tanks baffled for extra support and durability?
Yes, all tanks have a minimum of two baffles for extra support, durability, and to help reduce fuel slosh.
Estimated Product Handling: 2 to 3 days
After placing an order, customers have up to 48 hours to cancel the order unless the item has been crated and/or shipped.
Orders for large or heavy items ship via a trucking carrier. Freight delivery is typically 2 to 6 business days, allow extra time for remote locations.
The Freight Carrier or Tucking company will contact you to set up an appointment time before delivering. Once your product leaves our warehouse, we will send you an email with a link to the freight carrier’s website and the tracking number. Tracking numbers take 1 business day to update.
Please inspect your package upon delivery. If there is obvious damage, please note the damages on the delivery receipt. Contact us within 24 hours to report the damage, by either e-mail or phone. Please retain all original boxes and packaging.
Returns (Applies to The Fuelbox products only)
All returns must be pre-authorized and require a return authorization. Please email email@example.com to request a return authorization.
Returns are accepted for brand new and unopened products only. No products may be returned after installation or attempted installation.
All returns must be requested within 30 calendar days from the delivery date.
The product must be in the original packaging and include all packaging materials, crates, boxes, and pamphlets.
All returns include a 25% restocking fee.
Customers are required to pay for the cost of return freight shipping.
The final return amount will be calculated as the Purchase Price less return shipping cost less the 25% restocking fee.
The Fuelbox by Z Manufacturing warranty is a 3 years limited warranty against defects in material and workmanship. Z4 Manufacturig, Inc. sending unit, install kits and transfer pump sending units are covered by a warranty period of one year. Our warranty is effective in the U.S. from the date of purchase to original purchaser. Original Purchaser shall mean the person who first purchases a vehicle in which a Z4 Manufacturing Product has been installed as original equipment. The Z4 Manufacturing Fuelbox is designed for use with diesel fuel only. Z4 Manufacturing, Inc. reserves the right to examine the claimed defect upon return of product to our facility with all shipping charges being prepaid. No payment will be made for parts purchased or repaired in the field without prior authorization from Z4 Manufacturing Inc. If the claim is determined valid, repair or replacement will be made at manufacturer’s option.
The warranty for replacement parts shall be for the unexpired term of the original warranty. This warranty will not apply when product failure is caused by conditions beyond the control of Z4 Manufacturing, Inc. such as: (1) Damage from misuse or negligence, (2) Damage caused by improper installation, (3) Damage caused in shipment or improper handling, (4) Product ordered incorrectly. This warranty shall be void if the product is altered in any way. This warranty does not cover the following consequential damages: Loss of use of warranted product, loss of time, inconvenience, transportation expenses, expenses for travel, lodging, fuel, lost revenue, and loss or damage to personal property.
Aluminum Tanks – 3 Year Warranty, on all component parts, and against defects in material & workmanship
AFC Products – 1 Year Warranty Fuel Pump1 Year Warranty limited to Warranty provisions of Original Manufacturer
Transfer Pump – 2 Year Warranty limited to Warranty provisions of Original Manufacturer