AUXILIARY FUEL TANKS?

Martinjmpr

Wiffleball Batter
So here's my question: Are you focusing on the solution or are you focusing on the problem? You said you thought it would be nice to extend the range on your FJC and then proposed a solution of an aux tank, but it seems to me that your starting position ought not be the solution, but the problem.
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What kind of range are you getting now, and how has that been a problem, and what kind of range is it you think you need?
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In your first post you stated that $1500 for an aftermarket fuel tank was too much, so there's kind of an upper limit on how much you're willing to spend, yes?
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Seems to me if you start off with a description of the intended goal (as in "my intended goal is to have a range of at least XXX miles off road") then you can start looking at the issue from the standpoint of which solution is the simplest and/or most cost effective.
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Just as an example, the stock tank on an FJC is what, 20 gallons or so (I'm too lazy to look it up)? So it would seem to me that if 10 extra gallons is what you anticipate you'll need, you have to weigh the cost and complexity of adding another 10 gallons in an auxiliary tank against the relatively simple expedient of strapping on a couple of 5 gallon/20l NATO fuel cans, which can be easily done on an FJC.
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OTOH, if you anticipate that you're going to need, say, 40 or 50 gallons total fuel, then I could understand wanting a bigger tank because although there are people who think nothing of strapping 6 fuel cans onto their vehicle, I wouldn't consider it prudent or safe to do so in most cases.
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So my first question would be, how much total fuel do you need? How much will be adequate for what you need the vehicle to do?
 

Strider

Observer
I would like about 500+ mile range. I will eventually be towing a trailer so that is another factor. I would like to install a 15+ gallon ( 30 would be nice if it will fit ) auxiliary tank and then I can carry two jerry cans on the back.
I have been looking at pre-made tanks for other vehicles to find one that fits. Relocating the muffler would allow a tank in that area but it looks like too much trouble.

I would fill the aux tank up fir long trips and leave it alone on a daily basis.

I have seen bladders and considered that, but it seems a tank for another vehicle is a lot easier.
Welding a custom one would be great but the comments are discouraging-seems almost like a magical act or rocket science.
 

Martinjmpr

Wiffleball Batter
If money was no object I think having a tank fabricated would be feasible but it sounds like money is an object.
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To be honest, $1500 for an aftermarket tank doesn't sound outrageous to me, considering that it would have to be safety-certified as well as emissions compliant. Not like in the old days when you could bolt just about anything up to your vehicle and drive off down the road (even then I'll bet that circa 1975 or so a new tank would run you nearly $300 - $400 which, considering inflation, would probably come close to $1000 or more in today's $$.)
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If it was anything other than fuel I think people would be encouraging you to "roll your own" but when you're looking at fuel you're looking at something where the cost of failure is likely to be very high. Bottom line, I think you can have it cheap or safe but I don't think you can have both. ;)
 
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Strider

Observer
Again, great advice and information.

I checked out the fueltankparts.com. They seem reasonable and I am going to look into that.

Thank you all!
 

rayra

Expedition Leader
btw, what the OP describes is properly termed a 'transfer tank' and they are legion in the farming sector. All manner of shapes and sizes / capacities and connection methods. No need to cobble anything together, unless you just love a challenge or have a shoestring budget. It's all been worked out and packaged for sale.
 

rayra

Expedition Leader
Tractor Supply is one of the primary vendors, they have a lot of designs ranging from cubes you can tuck into a frame corner, to thin vertical tanks that can be sandwiched to the front wall of a pickup bed etc. They have many designs that are meant to fit behind and under typical pickup cross-bed toolboxes.

http://www.tractorsupply.com/en/store/search/fuel-transfer-tanks

NorthernTool is another
http://www.northerntool.com/shop/to...-transfer-skid-tanks+auxiliary-transfer-tanks


But take a look at usplastics.com, they've got a lot of poly tanks that will work with fuel and with some custome brackets, protective plate metal shields and some simple pumps, you can readily make a transfer tank. Just make sure you use a pump rated for fuel. Lot of folks run a filler neck up into a rear wheel well, or you can install an aftermarket billet fuel filler in the fender adjacent to and above the tank location.

Another way I have seen it done is putting a fork in the normal tank filling hose so that a regular fuel pumping fills both tanks, but then you have to later trigger an electric pump to shift the fuel from the aux tank to the original fuel tank. But I have no idea how that works now with modern sensor-filled systems that require a non venting cap. It ought to work the same, but I have no idea. It's been 30yrs since I saw that split filler solution, long before all this computerized crap we deal with now.
 

rayra

Expedition Leader
Don't know where you are going to fit a tank under that vehicle, the only clear corner seems to have the exhaust running thru it. Might get 12-15gal? in there. Two 20L fuel can's worth, hardly seems worth the trouble. A thin flat roof tank on a roof rack might be a better solution. Which will surely make people howl.

27869d1229660288-under-carriage-rust-perforations-advice-needed-p3150188.jpg
 

chaos616

Adventurer
Hello,

I was in the same predicament, we live in northern nevada, if you look on a verizon cell coverage map, there is a big area east of california with almost no coverage except on I-80, thats where we are. i understand wanting extra fuel on long offroad trips and just driving around, those same areas that don't have cell coverage rarely have gas stations as well. I agree you need to set a goal, but also agree 1500 bucks for a slightly larger tank is, well, a lot of money i didn't want to spend.

My goal was at least an extra 25 gallons, mind you i only get 12 mpg. however it will only be better if i get a diesel and get 22 mpg. I run larger tires and hate where the spare tire goes plus i do haul a lot of lumber and motorbikes in the bed of the truck so a in bed storage system was not possible for me (NOTE***, most of the in bed tanks are rated for DIESEL ONLY, due to the low flash point of gasoline).

I went to the junkyard and paid 35 dollars for a 1993 chevy blazer full size tank (31 gallons). I screwed up and didn't take the sending unit/pump for 35 dollars and ended up with a new sending unit for 70 dollars (oops). Instead of using a in tank pump, i just used hoses and clamps to build a pickup from the tank bottom.

I did this because i wanted to mount the tank where the spare went. mind you this isn't a bolt on application but so far it is very sturdy and has worked out quite well.

Tank in location


Final product in place with sending unit and pickup tubes (sorry no picture of the sending unit):


I decided to use a transfer pump so that i could not only fill my truck but also my motorcycles or other vehicles if need be. I used a GPI 8 gpm pump and it works fantastic. I use the tank and pump religiously and i don't stop for gas that often. My total gallons on board is 57 gallons and my range is 650 miles about.

Full cost:
tank: $35
Weld hole in tank (from junkyard bafoons): $80
Sending unit/hose and parts: $80
GPI pump (could use a cheaper option if you wanted): $270
Extra fuel gauge and wires: $25

Total: $490

Cost savings if smarter than me: $265

Sorry to hijack just thought i could be another idea, similar to what rayra was suggesting!!

Cheers,
 

rayra

Expedition Leader
Real nice work, chaos, especially the new framing. Do you have a protective plate under the added tank?

as a side note, The suburbans with the spare underneath typically have a 32gal tank, the older models with the spare in the rear cargo area have 42gal tanks.

Tons of poly fuel tanks, pretty inexpensive
http://www.usplastics.com/search/?q=gas+tank&view=g
 

chaos616

Adventurer
Hey rayra, thanks! Yeah there is the stock skid underneath. I thought about building a larger heavier one, but realistically my bumper should hit things first, so the 1/8" stock skid plate is really a protective plate/weak skid.
 

Buliwyf

Viking with a Hammer
I would like about 500+ mile range. I will eventually be towing a trailer so that is another factor. I would like to install a 15+ gallon ( 30 would be nice if it will fit ) auxiliary tank and then I can carry two jerry cans on the back.
I have been looking at pre-made tanks for other vehicles to find one that fits. Relocating the muffler would allow a tank in that area but it looks like too much trouble.

I would fill the aux tank up fir long trips and leave it alone on a daily basis.

I have seen bladders and considered that, but it seems a tank for another vehicle is a lot easier.
Welding a custom one would be great but the comments are discouraging-seems almost like a magical act or rocket science.

Put a fuel tank on the trailer. Tons of room under there. Easy square tank. No messing with the truck. That way we can fill our bikes, generators, whatever, even our tow vehicle. Can't say I've really had fuel range issues in the states. As a motorcyclist with only 100 miles range tops. I have to constantly think of fuel stops and plan ahead.
 

otis24

Observer
I just started an aux tank project for my 2003 Tacoma. I'm shooting for a 590 mile highway range, or more importantly - offroad range of 400 plus miles.

Yesterday I purchased an auxillary fuel tank out of a 1998 Ford F150. The tank will go into the bed of the truck, under the camper shell. I'm rebuilding my sleeping platform to accommodate the spare. It'll have it's own filler and will function as a transfer tank using the tanks built in fuel pump and sending unit to a gauge in the cab of the truck. I picked up a momentary switch that you have to press and hold to pump fuel. I know I'll forget to turn off a switch.

I got the tank for $44. The switch was $2. The rest should be around $100 tops. I'm expecting to take a weekend...maybe more.

Just another idea.
 

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