Do Under Bed Auxiliary Fuel Tanks For Pickup Trucks Exist?

VD February 02 2022

An under Bed auxiliary tank helps you travel farther distances than your standard fuel capacity would allow. An additional fuel tank attaches to your regular fuel tank to avoid running out of fuel as often. In some cases, such tanks can double or even triple the typical fuel capacity of your pickup truck.

Owning a pickup truck, you're probably aware of the problem of high fuel consumption. No matter how much gas you put in the tank, it's never enough. And that's not so bad if you're always in town, where there are petrol stations all around and you can always fill up a full tank. Imagine yourself in a situation where you run out of petrol somewhere far away from the city, where there is not a soul for hundreds of miles. All you have to do is stand by the road and wait for someone to stop and tow you to the nearest station. If only it were possible to have more than one tank in the car. And there is such a possibility - install under-bed fuel tanks in your car and you'll always be sure to get to your destination!

Such Under Bed Fuel tanks exist for Pickup trucks and come in different sizes and weights. The titan fuel tank can provide an additional 30-gallon capacity to any pickup truck without adding too much weight. 

The installation process can be DIY-ed with no additional cost as long as you have the proper knowledge and some beginner tools. 

What is the purpose of an under-bed auxiliary tank?



An auxiliary tank is used to store fuel in case the main tank becomes damaged or runs out of fuel. The auxiliary tank can be connected to the main tank through a series of pipes and valves, allowing it to transfer fuel as needed. Auxiliary tanks are often used in aircraft or other vehicles that require long flights and may need extra fuel during the journey. They can also be used to store extra fuel in case of an emergency or for transporting fuel from one location to another. Auxiliary tanks are an important safety feature that helps ensure the vehicle can continue operating even if its main tank is damaged or compromised.

Benefits of Under-Bed Auxiliary Fuel Tanks

Auxiliary fuel tanks are a great tool for commercial vehicles, in particular those that travel long distances. These tanks can help save on the cost of fuel by extending the range of your vehicle. This is especially beneficial to businesses that have large fleets, or whose drivers often drive longer routes.

There are several benefits associated with auxiliary fuel tanks, including:

  • Better fuel efficiency. Auxiliary tanks allow your vehicle to carry more fuel, which means it can go farther before needing a fuel stop. This reduces the number of steps you need to make along your route, saving you time and money on your journey. The longer your vehicle can travel between fills up, the less fuel you'll consume overall.
  • Reduced risk of breakdowns. When you carry extra fuel onboard, it reduces the risk of running out of gas in an isolated area or while stranded on the side of a busy highway. This can help keep your employees safe and reduce the stress and risks associated with unexpected vehicle trouble. Plus, when you're able to continue along the route without having to wait for a tow truck, you can save on labor fees and start meeting your schedule.
  • Fewer emissions. Auxiliary fuel tanks help reduce the amount of time your vehicle spends idling at stops on its route. This means less pollution from exhaust fumes, which is better for both the environment and public health.
  • When hauling a lot of weight, your pickup truck will use up more fuel than usual as it has to exert the engine more aggressively. This can cut down your coverable distance even more. Auxiliary tanks ensure that you can confidently go through long, unknown routes without worrying about having to fill up soon.

Types of Under-Bed Auxiliary Fuel Tanks

When purchasing an Auxiliary fuel tank, you may come across two different types with their own sets of pros and cons. Below is our guide on each type and what they have to offer.

  • Truck Bed Fuel Tank with Pump

  • truck-bed-fuel-tank-with-pump

In such an auxiliary fuel tank, the fuel is transferred to the main tank with the help of an electrical pump. This pump needs to be switched on and off manually from within the vehicle. It carries the benefit of being convenient as you won’t need to get out of your car to refill the tank. 

However, when not switched off in time, the fuel will keep pouring into the main tank, causing leakage. For this reason, most electrical pump tanks come with a return line that pushes the excess fuel back into the auxiliary tank.

  • Gravity Flow Fuel Tank

  • gravity-flow-fuel-tank

As the name suggests, its mechanism simply utilizes the pull of gravity. The main tank gets filled up with a gravity flow tank as soon as some fuel is burned. This helps you get a constant full tank at all times until the additional tank runs out of fuel. This one doesn’t involve the danger of leakage or any manual input either. 

How to Install Auxiliary Fuel Tank?

Installing an auxiliary fuel tank does not have to be expensive or time-consuming. Because it takes only 2 hours, it's best to DIY it and save on expensive labor costs. Below is a straightforward guide to fixing up your new tank in no time.

Depending on the fuel tank you buy, you might get an installation kit with it, including all the tools and bolts you need. Even if you don’t, you can simply buy the required equipment from any local hardware store. 

Step 1 – Make sure your workstation and truck bed are clean.

The first thing you always do when attempting to install an auxiliary fuel tank ensures there's plenty of room to work. You'll also make sure any things inside the bed of the truck, such as a bed mat, are removed.

Step 2 – Ask your mate to help you a little

Under-bed auxiliary fuel tanks for pickup trucks are typically rather light. Having another set of hands, on the other hand, will be quite useful as you lift the tank to put it in your truck's bed. This not only reduces weight but may also prevent any damage to your vehicle's finish due to scrapes or scratches.

Step 3 – Determine the location of the auxiliary fuel tank

Before you start drilling holes in your pickup bed, first make sure to place the under-bed auxiliary fuel tank where it will be installed. You want a bit of space on all four sides for this important installation so that there are no parts rubbing against any portion of the truck's interior—which could cause potential damage!

Step 4 – Mark the holes where you will install the tank on the truck bed

All of our tanks include mounting tabs on the bottom edges, or in the case of taller tanks, on the bottom and higher back edges. After locating the tank correctly, you must make sure to visibly mark the ports where you'll connect the fuel tank to the bed of your truck.

Step 5 – Start drilling holes

Remove the auxiliary fuel tank from the pickup bed after you've identified the mounting locations. It would be a good idea to center-punch the holes' positions at this point to keep the drill bit from straying away from the intended hole location. Drill small holes first using a little bit like a "pilot hole" for larger ones. The final size of the hole should be just big enough to allow a snug fit for the carriage bolt. You can use a standard ratchet and socket to remove the bolts, but it may be difficult to get to all of them.

Step 6 – Install mounting hardware

The 3/8” rubber fuel supply line should be run from your new tank before you bolt it into place. Most people simply drill another hole in the bed of the truck and thread this down to where their existing factory filler neck is, but on some models, access can also come by removing these plugs near posts that hold up corners of stake pocket support structures located at the bottom side if their vehicles' trunks or compartments are known as "beds. It's also possible that these are available, in which case you can pull out the rubber stopper and make a hole in the center of it to fit the fuel line. Replace the plug and run the line down towards the factory fuel neck. The next step is to install your auxiliary tank, at which point you'll use bolts and nuts.

Step 7 – Set up the Filter

If you choose to use an in-line fuel filter, be sure to prime it before installation. To do so, drain the fuel from the gasoline tank and fill it with fresh gasoline.

Step 8 – Install the Adapter Kit

Step 9 - Install the Under-bed auxiliary fuel tank

The final step is to actually fill the auxiliary fuel tank. Your tank will include a shut-off valve, to which you'll connect your rubber fuel line to. This valve may be left on at all times, or some people prefer only to open it when they want to fill their tank using gravity. Under-bed auxiliary fuel tank, when filled with gravity, will slowly fill your truck's main fuel tank.

Assuming you have a functioning shut-off valve, open it now and allow the fuel to flow into your truck's fuel tank. If you don't have a shut-off valve, you'll need to keep a close eye on the level of fuel in your auxiliary tank, as you can't turn it off once it's flowing.

It's also important to make sure that your fuel gauge is set correctly, as filling with gravity can cause the level of fuel in your main tank to vary from what's shown on the driver's dashboard. This can lead to some confusion when refueling at a gas station, so it's best to get it right from the start.

If you're using a pump to fill your auxiliary fuel tank, the process is much simpler. Simply open the shut-off valve and let the pump do its job. Once the desired level of fuel is reached, close the valve and disconnect the hose.

If you are still not sure how to install an under-bed auxiliary fuel tank on your truck - check out this video - and we hope that everything will become clear for you!