Auxiliary Fuel Tank (Spare Tire Area) Parts and Build Ideas

I have been sitting on my aux fuel project for a while, I need to get this thing going. I found a fuel tank that should fit pretty nice in the spare tire area (2005 DCSB).

73-81 K-5/Blazer 31 Gallon tank (Dorman 576-311) ~$100
28.75"L x 28.125"W x 12.75"H


My plan is to use the Holley In-Tank RetroFit Fuel Module, it's $450, but that is cheap for what it solves. If you look in the corner of the fuel tank, you can see a spot to cut and install the pump.

http://www.jegs.com/i/Holley/510/12-130/10002/-1?CAWELAID=230006180020435404&CAGPSPN=pla&CAAGID=15769068431&CATCI=pla-208916254151&catargetid=230006180037476177&cadevice=c&gclid=CPnniujA-dICFRKTfgodiAIHBQ

The sending unit is around $40.

Mounting the tank at a slight angle, with the pump foreword should help with clearance, free surface effect and liquid pick up. I am undecided on setting the system up as a transfer system to the main tank, or completely wiring the second tank in as direct fuel delivery.

Thoughts/Ideas?

 

I had the same idea of a 2nd gen auxiliary fuel tank;

https://www.tacomaworld.com/threads/auxiliary-17-gallon-fuel-tank-idea.477475/

And here is one that a member recently finished his and is using it with no issues;

https://www.tacomaworld.com/threads/piecing-together-an-aux-fuel-tank-setup.475581/

Are you worried the 31 gallon tank will put too much weight (so far back) with a full load of fuel? 31 gallons = ~186 lbs of fuel. The one we had on our '88 was 15 gallons- so added 90 lbs when full.
Also if you plan to go with a transfer system- the auxiliary tanks fuel 'weight' can't exceed the oem tanks fuel weight for fear of pushing it into the evap system (could cause evap codes too). Once you add in the extra forces when braking or off roading and you should keep the auxiliary fuel load a fair bit lighter to prevent issues. I also plan to use a tank with baffles to prevent fuel slosh.

I am installing rear bags to help with the extra weight (when I finally get around to building it) but you could also use Timbren bump stops.

Good luck with the build, I will be following along.

 

I have thought about the weight issue. Compared to typical Jerry cans even farther back on the swing gate, I should be getting a little advantage, but you are right 200lbs after steel fab and brackets is nothing to look away from. I am getting 15mpg, that puts me at around 250 miles per tank. I want a solid 700 mile range, I don't see any other way of storing that much fuel without compromising bed space.

I'm not too worried about the baffle issue (or should I be?), as long as I can get a decent angle on the tank when installing it.

 

Here is another way to increase fuel capacity;

https://www.tacomaworld.com/threads/custom-35-gallon-gas-tank-for-09-tacoma.204307/

You could get a fab shop to make one for you as I don't think anyone was able to get the ones in the post.

Could increase the tank that goes in the stock location as well as an auxiliary tank to get over your 700 mile range.

 

THAT IS A SWEET JOB! ^^^

That would be my preferred method, I don't think I could get a fab shop to do this for less than $1500. After all of the mess of wiring and adding a filling port, it might be worth the time and money though.

 

Will it get filled up through the Bed ??

I would use a Stock Denso pump with the 3 line bracket Toyota sending unit that matches the Truck gauge

A dual tank solenoid this would be wired to switch tanks back and fourth .

Turn on the pump and switch the gauge

just a matter of running the lines and electric

Since your in California I have no idea what needs to be done to be legal

Most all my vehicles had dual fuel tanks set up like this

Just a idea

 

How about this (cheepie). I installed two 20 Ga diesel tanks on my 30 Ft rv and used an electric gasoline pump as a transfer to the main 50 Ga tank via the fuel fill tube. I just burn down the main to below 1/4 , switch on the pump and fill er up ! It has been working for over 50K mi. just fine.
The use of the electric gas pump makes the job cheap ($40) and easy to do. I think that it would avoid problems with the smog stuff too but my old diesel does not have an evap. system to worry about so I really don't know.
Using the "transfer pump" as described above I am about to install a 10-12 "booster tank" on my 08 Tacoma just to extend my range to 400 + Miles, if the anti evap is a problem I will add a solenoid valve.
Good luck

 

I plan to move my spare into the bed in the near future and would love to put an aux tank in its place, but I'm debating whether its worth the effort given the potential problems with the evap system that folks are talking about. As a transfer system, I'm leaning more toward the portable type systems like this...

Moeller 630012LP, Portable Fuel Tank, 12 Gallon, 45 Liter, 12 Tall Profile

https://www.amazon.com/Moeller-12-G...D=41JwYdQnzJL&preST=_SX300_QL70_&dpSrc=detail

I have been looking for a toolbox / fuel tank combo but they are hard to find for the Tacoma and realistically they take up too much of the bed for how often I would need the extra fuel. I would have to use a trailer to haul my dirt bike.

I'll be hoping you find a good solution with your method! Good luck!

 

I can't find the thread but somebody has this transfer tank mounted underneath a shallow bed toolbox in their bed.

$483 Moeller Marine 031818, Topside Fuel Tank 15 Gallon, 57 Liter

https://www.amazon.com/gp/aw/d/B000MTB79M/ref=ox_sc_saved_image_2?smid=ATVPDKIKX0DER&psc=1

 

Nice! Thanks for the tip! I'll dig around and see if I can find the thread.

 

Just a suggestion, maybe talk to @paranoid56 about his 35 gallon "stockish" location big boy tank , I forgot if he sold his second one.

 

it has been sold but still loving my 34gal tank

 

Ah, ok. I forgot what brand it was, maybe you can get him info if he wants, thought I would tag ya. lol Thought it was 35 like my Ford's is.

 

@otis24

https://www.tacomaworld.com/threads/otis24s-build.372874/page-2#post-10696061

 

You'll only have evap issues if you're an idiot such as myself and forget to turn the pump off. The less complicated method is transfer tank. Switching tanks would be super, super nice.

Extra weight isn't all that much of an issue. You'll find that you'll either transfer the fuel out of the tank ASAP or if you do switchable tanks just run the rear tank 1st. Also, like you said it's lighter than adding a swing out with extra tanks etc.

 

Oh yeah...you're sorta local too. If you need a hand with anything just let me know. I live in the south Bay. Petaluma isn't super far and you guys have loads of good breweries up thata ways.

 

Speaking of NorCal Breweries feel free to share your North Bay Brewery Visits here:
https://www.tacomaworld.com/threads/nctwbvc.512850/

 

I have installed pretty much all of the wiring and fuel switching solenoid. I ditched the 32 gallon idea and went with a 94' S-10 fuel tank, all new online. The tank I believe is a 18 gallon. I am using a three position rocker switch to select tanks, I am down to welding a dual neck filler and installing the tank and components. I have been really busy this summer so I don't think I am going to get around to this until this winter.

The cost has become dramatically cheaper due to not using the Holley in tank fuel pump, which is really not needed at all as far as its performance side. It was a great workaround to getting any fuel tank to work with this type of application. I think once everything is said and done, it will have cost me around $500 in parts, wiring, etc.

The only potential issue that I did not think of at the time was traveling in other countries like Mexico, which will be happening in the near future. I have a feeling that if the second tank is detected, they could potentially remove it to check for contraband.....

As soon as I have all of the components working correctly, I will post a detailed build and list of parts that I used.

 

@otis24 takes his truck to Mexico. Let's see what he says. Just don't eat a powdered donut before you get to the security stop lol.

 

I had a good laugh reading your post @Dalandser, nice! I think anything from the border, down to like Ensenada, would be just fine. It seems like when you start crossing borders into other Central American countries is when things can get inconsistent and weird. It didn't even cross my mind until watching the XOverland series last year and saw the obstacles they routinely had to face. I have read some crazy stories on Expedition Portal also.

@otis24, what experiences have you had? I am guessing the border into U.S. should be GTG?