Trailed 6-Gallon “Spare” Tank Overview & DIY Guide For the 5th Gen 4Runner
Traveling into the backcountry by vehicle can be a safe and rewarding adventure if properly prepared.
However, if you are not prepared things can turn into a post-apocalyptic movie scene, quickly. Liquid is essential for life, both for us and our rigs, having plenty of water and fuel will help ensure a safe return from any adventure.
That is where the Trailed “Spare” Tank comes in. These easily portable tanks will hold 6 Gallons of liquid in any place you can mount a spare tire. Notice that I said liquid and not just fuel tank.
Find it online
- Trailed’ Spare: Check Price
- Shaker Siphon Hose: Check Price
- Scepter cap and nozzle: Check Price
That is because the Trailed “Spare” Tank is constructed of Linear Low-Density Polyethylene which means it is food grade and can hold water as well as fuel. However, like any plastic container, once the fuel is added, it should no longer be used for potable water.
Size and Capacity
The tank is only 3 inches thick and 29 inches around and can be stacked together. To give you an idea of what this looks like, 3 tanks stacked together are the equivalent to the factory spare on the 4Runner. That is 18 gallons of fuel or water in what could be otherwise wasted space. Even more so, a BFG KO2 at 285/70 is around 12 inches adding another 6 gallons for a total of 24-gallon capacity.
If you have ever had to carry full jerry cans across a motor pool, then you know liquids are heavy. Exactly how heavy, well that depends on the type, and for some, the temperature (the colder fuel is the heavier it is)?
- 1 gal of H2O = 8.34 lbs x 6 gal = 50.04 lbs + 10 lbs for the tank = 60.04 lbs
- 1 gal of Regular Gas (87 Octane) weighs 6.216 lbs x 6 gal = 37.3 lbs + 10 lbs for the tank = 47.3 lbs
- 1 gal of Premium Gas (91 Octane) weighs 6.35 lbs x 6 gal = 38.1 lbs + 10 lbs for the tank = 48.1 lbs
This can add up to a significant amount of weight depending on the requirements for the trip.
For me, the perfect set up for longer unsupported adventures would be at least 2 fuel and 1 water tank as the 4Runner is much thirstier than I am. This would equal 154.64 pounds. One of the main benefits of the Trailed “Spare” Tank system is that it keeps all of that additional weight low and improves the center of gravity versus having it on the roof.
Accessing gear when you need it is important and utilizing the factory spare hoist negates any additional mounting requirements. Using the OEM toolkit drop the spare tire.
Removing Spare Tire (DIY Guide)
If you have more than one spare tank, then stack them together. On the side, there are 2 nubs that correspond with 2 indents on the opposing side so they will lock into each other.
Reinsert the hoist into the center opening. Make sure to bend the tab that fits into the wheel stud hole flat, as it will cause damage. See below in the Durability section of this post.
Crank it up just like a spare. It keeps it tucked up out of the way and a single tank just disappears underneath the vehicle.
I think 3 tanks are the ideal number as it keeps everything tucked under, but just keep in mind if you are doing any serious rock crawling you may want to drop down to 2.
Since I haven’t got my tire swing just yet, I attempted to place the tank above the spare to see how much clearance I would lose. Short answer… a lot, I would not recommend this… Ever.
At the Trailed “Spare” Tank 12 o’clock is the recessed port to protect the cap. It uses a standard self-venting Scepter cap and nozzle, so it can easily be replaced if lost or broken.
At the 6 o’clock position is a flat base that allows it to stand up better. I would still lean it against something as it is still thin and heavy.
There are 4 comfortable handles at the 45-degree marks, which allow multiple ways to carry and pour.
It also gives you additional tie-down points if needed. They remind me of some nice oversized plates from the gym.
Pouring fuel into a gas tank is never fun, no matter what type of container.
It is an awkward and messy process at best and that is why I have given up on pouring fuel. I have instead adopted the use of a siphon hose.
The one I use is an inexpensive shaker siphon hose as some of the ones with pumps leak after time and take up more room. It has a brass end with a little marble and spring that you shake in the fluid.
It’s less strain and mess, as long as you have a zip lock bag to keep the hose in afterward. Or better yet let it sit out for a few minutes to let the fuel evaporate before bagging it.
I know that there will be the question of “What if you still want to carry a spare in the factory location?”. The Trailed “Spare” Tank can still be carried anywhere that a spare can be mounted. For the rooftop application, you can use something like the Front Runner spare wheel clamp to mount the tank.
If you are only using one or two tanks this will keep a very low profile. This would also be a great application for water storage as it could heat up in the sun, and be used for showers.
Another added benefit is that Trailed is made in the U.S.A., more specifically in Salem, Oregon.
So it’s supporting a local small business that is a part of the community. They also have a 5-year manufacturer warranty where they will replace or repair any defects. If things do go wrong that are environmentally induced (read, you smacked a rock with one), then they can be repaired using plastic welding.
If for some reason that it can’t be repaired it is fully recyclable, so it continues to be useful in another life.
These things are stout!
In a few hundred off-road miles it still looks new. However, since I only have one at this point and it is tucked way up it hadn’t been fully torture-tested. The largest damage sustained is when I forgot to bend down the tab that locks into the spare wheel stud hole and cranked it up far as it would go.
I really thought it would have punctured with near 50 pounds and all that force on a small metal edge but to my relief just a small dent.
Take my money! Initially, I was extremely interested in the concept but was unsure of the application. However, after putting it through the over 500 miles of backcountry trails it performed flawlessly.
I like my gear to be adaptable and durable and that is exactly what the Trailed “Spare” Tank is.
Wonder if there are photos available of two tanks connected to a water pump system.
I just read this article and EVERY comment. How long have you used the tank for fuel and are there any issues? I recently posted a YouTube video installing one under my truck and had several concerning comments abouts its safety with fuel. Now Im afraid to test it out lol
Just bought two. They feel stout, very stout. Planning to run one water and one fuel. Be sure to rinse all the plastic shavings out before use. At$150 per, you would think they’d arrive clean, but they didn’t. After lots and lots of rinsing and leaving them full and upside down, not a drop out of them.
Did you end up using these for fuel? If so, whats the verdict?
You’re suppose to bend that tab down flush so it doesn’t puncture the tank.
Yep, I mentioned that I had forgotten to, and it only had a small dent in the tank. Super Stout!
Can you elaborate on the durability? Meaning, do you have a lower the tank and “vent” them to release pressure when the climate changes? or is it a solid material like rotopax where you don’t have to worry about expansion and seepage? I want to get these but i don’t have to deal with venting. Thoughts?
Haven’t seen any expansion, I am sure that there is gas expansion, but it is not noticeable. I am sure it helps that it is underneath, out of the sun. It may be more pronounced if mounted on the rack and getting full heat from the sun.
I looked into these. What I would like to see is some further refinement. If they made an add on kit that connected to a compressor to pressure the water out of a hose, or a 12 volt pump, and a way to fill it without actually going through the same routine as having a flat tire. I think its a great concept but could be better in function.
I thought about this as well. I would not go with air as it will lose pressure to quickly. They have small 12V drop in pumps with nozzles that would be perfect for these. Since the cap is a easy to find Scepter you could easily rig a sealed system with a few fittings and silicone.
I noticed on their website that these are not certified for fuel storage. I can see insurance issues if these are used for gas and something happens.
Yes you are 100% correct, these are not certified for fuel storage… yet. They will be working on getting them certified in the near future. Honestly, my military fuel tanks don’t even state that they are certified either.
I clicked because “KILL rotopax” headline in my email. I am one of the guys who thinks Rotopax are extremely overrated for both fuel and ESPECIALLY water. In fact, I controversially group them in with RTTs – looks cool, seems great, everyone wants ’em but in practice, expense, and functionally actually suck. I have a rather visceral hatred of rotopax after use (unless you trail ride motorcycles).
Anyway, this new kid on the block looks pretty cool and i love the market with great options. Thank you trail4runner!
Thanks for the comment. I believe that there is the right tool for the right job, and there is room for both in the market place. However, I do agree that rotopax are the best option in the moto world.
I am wondering how good this would be for just using as weight in the winter. Living in Northern NY we get a lot of Lake effect, I’ve had trouble with finding a good spot for weights in the past 2 years. 3 of these stacked with water mixed with antifreeze would be good weight!
Or use actual weights 45 plate and 35 plate ?
That is a great idea! I didn’t think of that since I’ve been in Arizona for way to long.
180lbs that low with 3 tanks of that mixture would be a lot safer down low than the tractor weights I had loose in the back! My spare (LT285/70/17 only weighs 70-90lbs so that’s a good improvement. If you were loaded up for a trip it would be better to have the spare tire than the weight, but being my DD the weight in the winter would be super helpful!
The only concern would be adding antifreeze, I would use RV potable antifreeze so I could still use them for drinking water.
I would rather have the spare tire exposed to rocks and ground impact than a fuel tank. Seems like a Jerry can mounted somewhere less exposed is a better solution.
That was my thoughts initially. But they are well tucked under the vehicle and thicker than a jerry can. I would stack 2 fuel close to the body and one water on the outside as a precaution until I’m comfortable with it. But like I said they can also be used on the roof rack for lower profile tank options.
I’m thinking move the tire to a swing out, and run two or three of these in the spare tire location.
This is my plan as well, perhaps next stimulus check…
Seems on their homepage they do indeed show multiple cans in that location.
This is pretty awesome!
Like how much ground clearance loss are we talking here?
This would be perfect if I could still keep my spare down there. Hoping the might come out with a “slim” version in the future.
I don’t think they can get them much slimmer at 3″. Ground clearance will depend on your tire size, but if you measure down 3 inches that will give an idea.
it would be much lower in capacity, but it seems like one could be designed that fit entirely within the spare wheel — i’d get one if that was the case (no loss of ground clearance)