How bid of aux tank with 5th wheel?

[davidschaffer]

I am having an auxiliary tank built and I want it as big as possible. My question is, how big can I go if I plan to haul a 5th wheel? I have an 8' bed and am hoping to build a tank that will be around 64" wide by 32" deep by at least 24" Tall. Is this possible? Or would the 5th wheel need more clearance? Thank you.

[jesilvas]

I'm running one of the L shaped ones that are 105gals and a tool box in the crook of it that is just as tall and as far back in the bed as the bottom of the tank and I clear it. If I pitch the truck nose up and trailer butt up and the middle is down and turn at the same time, I might hit it. But that's with one fifth wheel. It's going to depend on the pin box, end cap, where your rails/hitch are placed, and such. I'd hook it up, get it in the most awkward position you can where the corner of the end cap is as far up as it will go and then measure.

[davidschaffer]

Originally Posted by jesilvas

I'm running one of the L shaped ones that are 105gals and a tool box in the crook of it that is just as tall and as far back in the bed as the bottom of the tank and I clear it. If I pitch the truck nose up and trailer butt up and the middle is down and turn at the same time, I might hit it. But that's with one fifth wheel. It's going to depend on the pin box, end cap, where your rails/hitch are placed, and such. I'd hook it up, get it in the most awkward position you can where the corner of the end cap is as far up as it will go and then measure.

I appreciate the reply. I haul boats and campers around the country a couple of times a month. I am only licensed for bumper pull but am thinking about getting the 5th wheel/goose neck added to my MC #. So my problem is that I will never know how the 5th wheel is going to ride until I pick it up. I want to have a 200+ gallon tank because I converted my truck to run on wvo. Right now I use my 51 gallon heated tank and bring 3-4 55 gallon drums of oil with me. It is a pain to transfer the oil while on the road, especially in cold temps, so I want a bigger tank and if possible, the ability to pull 5th wheels., yep, its a lot to ask, but hey, it might work.

[jesilvas]

Do you have a toolbox at all? Or is going to be just the fuel tank?
What you could do is make one that is not very tall, but full width. Bring it up to no higher than the bed rail that way you'd hit the bed rail before the tank Are you going to have a pump or anything at the top of the tank? If so, put the bungs for it up at the front and they'll be fine.

[bulldog55964]

The problem there would be hooking the fifthwheel up it would have to be "c" shaped so the fifth wheel can pass though the center so when hooking up/unhooking you dont hit your tank (how big of a fifth wheel can you haul when you have 1700 lbs + tank weight in the bed)

[jesilvas]

I was thinking make it go back to the rails in the bed (or whatever kind of hitch you have) and then just be a big rectangular tank from the front to the hitch then up to the bed rails.
As far as weight limits you'd have to figure up how heavy the truck will be totally loaded with fuel and all. Then whatever the difference is between your truck's GVWR and the total weight would be the tongue weight you could put on the truck.

[davidschaffer]

The tank is going to look like a job box. It will have a lid with about 3-4" of space under the lid for tools and an area for filler and vent. I am currently driving a 96 F350 srw. I want to upgrade to a 01' ish f350 drw witch will have a higher weight rating. I won't ever pull anything heavier than 15k and would probably try to keep it in the 12k max range. In order to get 200 gallons with a 3'' lid/tool store, I would be around 26h''x33d"x63w". I believe my bed rail is around 18" high ( I will measure it later to be sure ). It sounds like if I want that big of a tank, I won't be able to pull 5th wheels.

[bulldog55964]

The other thing i just thought of is if its not OEM tank after 117 gal you have to deal with HAZMAT in Minnesota so check your local laws you may have to plumb two separate tanks together to stay legal at 200 gal

[bulldog55964]

TSC sells a tank just like what your describing with 97 gal and a tool box and its so big it cant fit in a short box truck (wheel wells) i have the 60 gal aux/toolbox and it fits perfect up to my gooseneck rails

[bulldog55964]

Sorry this is the one i was thinking of its Northern Tool but TSC has one similar
RDS Fuel Transfer Tank/Auxiliary Fuel Tank/Toolbox Combo — 90 Gallon, Model# 72894 | Auxiliary-Transfer Tank + Toolbox Combos | Northern Tool + Equipment
I think it is gonna be hard to put another hundred gallons in front of the gooseneck