RMP&O
Expedition Leader
I had done this in my 04 Tacoma awhile back when I had the truck. We installed this in late 2009 so I guess it has been going on 5yrs now. I got rid of the truck in 2011 but did do about 40,000 miles in it with the aux tank before I got rid of it.
I figured this may be helpful and useful to some of you guys with a Taco. Even with a 4-runner or 80-series it would be about the same thing or any truck for that matter where you are putting an aux fuel tank in the stock spare tire location. So here is a little write up on the aux tank we did with some pictures.
First up obviously the stock spare tire location needs to be relocated to the rear bumper or inside the back of the truck or whatever. The aux tank installed where the stock tire was located. This is the easiest location to do this and requires the least amount of work. My Tacoma had pretty bad range and this was the main motivation with adding the aux tank. To increase range. If I recall right the stock tank is about 19.5 gallons, my truck had a S/C and some other engine mods so I was never getting much over 250 miles out of the stock tank. Often I would stop for fuel at 200 miles due to distance to the next fuel up location. I am not really a fan of carrying jerry cans of fuel so I went the aux tank route.
In order to make sure we would not cause any issues with sensors, fuel pressure, ect ect we decided to set up the tank as a transfer tank. In other words, the aux tank would fill up the stock tank and we would keep it simple. To do this we removed the stock fuel filler neck and welded a fitting into it where the aux tank would dump.
I found a stock fuel filler door and recessed plastic body, if I recall right I also found a stock filler neck, 2nd hand junkyard stuff. The long term plan was to have the door welded into the quarter panel so it would be just like the stock door only farther back, in other words two fuel filler doors. I never did get around to doing that but did use the stock plastic recessed body piece. Had I kept the truck I would have eventually got the door welded in and paint matched for a nice clean look.
We took some measurements for the tank and at the same time decided to use the stock mounts on the frame for the tire carrier to hang the tank. We took our measurements to a guy we know who does custom tig welding on stainless and aluminum. We told him what we were after, where to put the filler neck, ect ect. he built us a stainless steel tank with baffles, a skid plate and pick up all ready to go. Cost was $500 and you should be able to find something similar in your area if you look around. In the end the tank ended up being 19 gallons.
We cut the filler door into the quarter panel and I bolted it in place. Since I wasn't welding in a door yet I just bolted the plastic insert to the quarter panel. The filler neck did need to be cut into the bed slightly, not much and it was in the corner against the bed wall so didn't bother me at all. Once the tank was hung and plumbed we installed a pretty high flow fuel pump (90gph iirc) inline from the aux tank to the fitting we had welded on the stock filler neck. We then wired the fuel pump up to a switch on the dash via an aftermarket fuse panel I had installed for some other things.
That is pretty much it. The truck now had 38 gallons onboard fuel. My range increased to over 500 miles. Before I would have had to stop 4-5 times in 1,000 miles for fuel I could now do it on two fuel ups. The best range I ever got out of the truck after the aux tank was a bit over 525 miles with 1/4 left in the main tank. I also was getting 14mpg which is poor compared to a stock engine. The way the transfer tank worked and because the aux tank put weight behind the rear axle I would transfer half of the aux tank as soon as my main tank was half empty. So driving down the road, main tank is at 1/2, flip switch and watch main tank fill up. Obviously I could do this twice and that is what I would do to get the weight from behind the rear axle as fast as possible. I had no gauge on the aux tank but never really found I needed one. If doing it again I would probably put in a sending unit in the tank and a gauge in the dash. The only problem with the set up was you could overfill the main tank if not paying attention. It took about 10 minutes to fill the main tank from 1/2. In the few years I had the aux tank in the truck I spaced a couple of times when transferring the fuel. The result, fuel will come out of the stock tanks cap and once or twice it messed up fuel pressure in the system causing the truck to run poorly. When this happened, I simply down shifted and burned up a gallon fast! My own stupidity to overfill the stock tank but it never caused me any big dramas and as soon as I burned off a gallon or less the truck went back to running fine. Something to think about though if you went to copy this set up.
The tank we had made, utilizing the stock brackets for the tire carrier to mount it.
The guy who made the tank also made the strap set up
Hard to see but the transfer tank fitting welded into the stock filler neck
My buddy cutting the 2nd door into the quarter panel
Test fitting it
Installed
The tank installed
We kept it nice and high
The high flow fuel pump
I don't have any pictures of the switch. It was simply a two position switch mounted on the dash. All up the install cost me $750 max. I think I was a fair share under that actually, tank $500, fuel pump $90, filler hose $15, fuel line $10, switch $20 so more like under $700. This was one of the best mods I did to the Taco, it transformed the truck for me.
Cheers
I figured this may be helpful and useful to some of you guys with a Taco. Even with a 4-runner or 80-series it would be about the same thing or any truck for that matter where you are putting an aux fuel tank in the stock spare tire location. So here is a little write up on the aux tank we did with some pictures.
First up obviously the stock spare tire location needs to be relocated to the rear bumper or inside the back of the truck or whatever. The aux tank installed where the stock tire was located. This is the easiest location to do this and requires the least amount of work. My Tacoma had pretty bad range and this was the main motivation with adding the aux tank. To increase range. If I recall right the stock tank is about 19.5 gallons, my truck had a S/C and some other engine mods so I was never getting much over 250 miles out of the stock tank. Often I would stop for fuel at 200 miles due to distance to the next fuel up location. I am not really a fan of carrying jerry cans of fuel so I went the aux tank route.
In order to make sure we would not cause any issues with sensors, fuel pressure, ect ect we decided to set up the tank as a transfer tank. In other words, the aux tank would fill up the stock tank and we would keep it simple. To do this we removed the stock fuel filler neck and welded a fitting into it where the aux tank would dump.
I found a stock fuel filler door and recessed plastic body, if I recall right I also found a stock filler neck, 2nd hand junkyard stuff. The long term plan was to have the door welded into the quarter panel so it would be just like the stock door only farther back, in other words two fuel filler doors. I never did get around to doing that but did use the stock plastic recessed body piece. Had I kept the truck I would have eventually got the door welded in and paint matched for a nice clean look.
We took some measurements for the tank and at the same time decided to use the stock mounts on the frame for the tire carrier to hang the tank. We took our measurements to a guy we know who does custom tig welding on stainless and aluminum. We told him what we were after, where to put the filler neck, ect ect. he built us a stainless steel tank with baffles, a skid plate and pick up all ready to go. Cost was $500 and you should be able to find something similar in your area if you look around. In the end the tank ended up being 19 gallons.
We cut the filler door into the quarter panel and I bolted it in place. Since I wasn't welding in a door yet I just bolted the plastic insert to the quarter panel. The filler neck did need to be cut into the bed slightly, not much and it was in the corner against the bed wall so didn't bother me at all. Once the tank was hung and plumbed we installed a pretty high flow fuel pump (90gph iirc) inline from the aux tank to the fitting we had welded on the stock filler neck. We then wired the fuel pump up to a switch on the dash via an aftermarket fuse panel I had installed for some other things.
That is pretty much it. The truck now had 38 gallons onboard fuel. My range increased to over 500 miles. Before I would have had to stop 4-5 times in 1,000 miles for fuel I could now do it on two fuel ups. The best range I ever got out of the truck after the aux tank was a bit over 525 miles with 1/4 left in the main tank. I also was getting 14mpg which is poor compared to a stock engine. The way the transfer tank worked and because the aux tank put weight behind the rear axle I would transfer half of the aux tank as soon as my main tank was half empty. So driving down the road, main tank is at 1/2, flip switch and watch main tank fill up. Obviously I could do this twice and that is what I would do to get the weight from behind the rear axle as fast as possible. I had no gauge on the aux tank but never really found I needed one. If doing it again I would probably put in a sending unit in the tank and a gauge in the dash. The only problem with the set up was you could overfill the main tank if not paying attention. It took about 10 minutes to fill the main tank from 1/2. In the few years I had the aux tank in the truck I spaced a couple of times when transferring the fuel. The result, fuel will come out of the stock tanks cap and once or twice it messed up fuel pressure in the system causing the truck to run poorly. When this happened, I simply down shifted and burned up a gallon fast! My own stupidity to overfill the stock tank but it never caused me any big dramas and as soon as I burned off a gallon or less the truck went back to running fine. Something to think about though if you went to copy this set up.
The tank we had made, utilizing the stock brackets for the tire carrier to mount it.
The guy who made the tank also made the strap set up
Hard to see but the transfer tank fitting welded into the stock filler neck
My buddy cutting the 2nd door into the quarter panel
Test fitting it
Installed
The tank installed
We kept it nice and high
The high flow fuel pump
I don't have any pictures of the switch. It was simply a two position switch mounted on the dash. All up the install cost me $750 max. I think I was a fair share under that actually, tank $500, fuel pump $90, filler hose $15, fuel line $10, switch $20 so more like under $700. This was one of the best mods I did to the Taco, it transformed the truck for me.
Cheers
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