Reserve/Auxiliary Fuel Tank?

[anothernord]

This topic didn't seem to fit anywhere specific, so I'll put it here.

Has anyone ever installed an auxiliary fuel tank in their car, Leggy or otherwise?

I'm re-doing my wagon truck area with a plywood floor and have found a nice spot where a 4 or 5 gallon cell might fit. I know the muffler sits below that area, but I don't have the stock muffler and there's about 7-8" of depth to work with, as well as a roughly 12x12" spot. Basically my plan would be to cut out the whole area and make a sheet metal box for a fuel cell to fit in next to the spare tire.

I could take out the spare and just put it it's place, but not having a spare tire is a pretty big minus.

Any input?

https://sl-i.net/FORUM/images/imported/2012/12/fuelcell-1.jpg

[harrymaneuvers]

I have thought about this quite a bit but never actually looked into it.

I drive from Sacramento to Portland quite often (more than 6 times a year) and would LOVE the ability to go an extra 100-150 miles.

Would your set up just be an auxilary tank that dumps into the main tank with the press of a button? Or would it be two separate takes with two separate pumps that you could alternate between?


I am thinking the first option because you would have a heck of a time wiring up a fuel level sending unit to your aux tank to accuratly show you the fuel level.

Next question is if it would be gravity fed or pumped into your main tank from the aux?

What would be REALLY cool would be the ability to not only have your built in aux tank... but maybe also have an open fuel supply line (like is used in outboard motors) where you can hook up another tank (on top of the aux) that could just sit in the rear cargo area (strapped to something) for even more.


Biggest issue I see for the wagons is the gas smell while filling up the AUX tank as there is no barrier like the sedans have with a trunk.

Unless you somehow put a y pipe with valve on the gas filler neck, you would be dragging the fuel pump hose into your hatch area.

[anothernord]

Yeah, that's the idea; a simple tank that pumps fuel into the main tank with a switch. I could potentially get fancy and use PIC microcontroller or Arduino that reads the resistance of the stock tanks's float meter, and flips on the pump when the main tank gets below a certain level, but manual control is simple and it works.

The biggest issue I'm seeing is how to make it play nice with the stock rollover valve, and the line that tells gas pump nozzles how to turn off. Maybe I could have a check valve in the line that goes to the stock fuel tank, to eliminate any possible issues with pressure going into the aux tank.

The essence of this tank is to use it mainly for emergencies. There's no reason to carry around extra weight in fuel when I'm putting around town. I'd fill it for long trips or adventures mainly.

With this configuration, there's not enough depth to have lots of stuff on the top of the tank. As it is, the filler for the tank would be at floor level, so I'd probably just live with the smell.

[Huffer]

If the tank is the same level as the main tank, you don't have to worry about vapors heading back into the smaller tank... but you will need some kind of a one-way valve and a vent system in the event of pressure buildup.

Also, unless you have a way to fully empty the tank you'll run the possibility of having old (and therefore bad) gasoline sitting in the car for a long time. This could play havoc with your engine and fueling?

I like the idea, but it seems too risky to offset the minor inconvenience of pulling off the highway, and emptying a 5 gal portable container into the main tank. Plus, it makes refuelling said emergency tank a lot less messy (potentially).

[harrymaneuvers]

So then what about the idea of a detachable reserve tank?

Take it out of the car to fill at the pump... you can completely empty it through the fill spout of the car. Depending on how heavy duty of a gas can you get... it could potentially already be rated for safe carry in a vehicle.

If you could just plumb a quick connect line like on an outboard motor... then you could have the extra amount when necessary. Maybe some floor straps to secure it. The quick connect hose could even store under your cargo compartment when not in use.

I am mainly thinking of long road trips, exploration in desolation wilderness (by lake tahoe), ect.



Probably pretty easy to rig a small electric pump that is inline with the quick disconnect hose.


Shoot... with a set up like that... you could put a series of containers in the back.


15 extra gallons anyone? That is only 90 pounds of extra weight plus whatever the cans and fuel lines weight.


Just throwing things out there.