View Full Version : Aux Fuel Tank

12-29-2009, 01:32 PM
My truck is an 02 F250 7.3 PS - very good truck. The fuel tank is only about 28 gal which don't give me a lot of travel time getting 10 - 11 mpg. I am wanting to add a 30 gal aux fuel tank in the bed of the truck. Has anybody had any experience with these, and if so, what do I need to be aware of? I appreciate your responses.

Larry Neal
2009 Big Horn 3385RL

12-29-2009, 01:43 PM
I bought a 37 gal. tank from Northern Tool along with the valve that gets installed in the rubber fill line. Easy to install and gravity feed works well , just have to open the petcock to allow fuel into the oem tank.
You can spend more and install a more sophisticated system that you can control inside the Cab but I spent less than $500 for mine.
Be aware they do not hold the capacity they advertise , I've never gotten more than 34 gal. in mine.

12-29-2009, 03:09 PM
I've got an '02 F-250 PS 4x4 long bed xtra cab and it has a 38 gal. tank. Do you have a short bed?

12-29-2009, 03:11 PM
With my GMC I went from 26 gallons to 52 with an "in frame" replacement.

Much better then filling up the bed. There are two main suppliers of in frame replacements.

Titan Tanks is one of them


My tank


MD Buck
12-29-2009, 04:00 PM
I have an 08 F250 and put a 60 gallon fuel/tool tank in the short bed that I bought from Northern Tool with their kit that ties into the existing fuel line and it was an easy install and I've had no problems in the year I have had it installed.

12-29-2009, 04:17 PM
I will admit Duane has the nicessed setup but I just couldn't bring myself to spend that much money. I put a 45 gal. tank in the bed with a fuel pump on it, so I can transfer what I want to when I want to.But if I had to do it over I would use the roll over fill that Northern sells with a shut off solinoid. Catch Cookie on the forum or chat line He just did one that way. JON :cool: :cool: :cool:

12-29-2009, 04:18 PM
In August 2007 I had an Aux tank installed in the bed of my truck. I looked at a replacement tank and it cost about $1200 and only gave me about 10 gallons of fuel more than the 38gal OEM. I could and did put 3 5 gallon cans in the bed of the truck when I traveled but when we decided to go full time we did not want to keep fuel cans in the bed all the time.

I also did not want to have to pump fuel into the fill neck of the truck. I wanted to flip a switch and change tanks.

A friend of mine had a tank in his truck and pointed me to American Tank & Tool Box in Frisco TX (http://www.auxtank.com/auxtank/home.asp). The tank is a 45gal Tank with a tool box above it. They will install it in Frisco or ship it to you with all the instructions for you to do the installation, with or without the electric valve to switch tanks. This tank has not failed me once. The people are very easy to work with and they can build you the tank you want.

Give them a try. They are a small independent business and do a great job.

BTW.. They make their tanks so you can put a cover over the bed with the tank installed..


12-29-2009, 04:42 PM
I have an aux. tank in my box as well. One thing I did do was to put a extra spin on fuel filter between the two tanks. I am awaiting parts to upgrade that to a water/fuel separator and 2 micron filter because the injectors in all the new diesels are very delicate and extremely expensive. All OEM filters are marginal in the new trucks, but even in an earlier version the extra filtration translates to more peace of mind.

12-29-2009, 05:34 PM
I had a transfer flow 50 gallon installed in the bed of my truck. It has an electrict pump and periodically will transfer fuel from the auxillary to the main tank. The guage inside the truck has a reading for the main tank, auxillary and the total of both tanks combined. It works great and I have not had a problem with the setup. It also sits below the bed so that you can put a fold a cover on the back of the truck. The fold a cover can be opended on either end and will work with a 5th wheel when folded back.


12-29-2009, 05:37 PM
I'll admit, the Titan is not the cheapest way out (mine was $895 including shipping, no tax) a few years ago. It doubled my capacity which for me is enough. On the highway I can do over 700 miles. That and last year with fuel reaching $5 a gallon - that was plenty.

12-29-2009, 05:52 PM
RetiredCPO nudged me into installing the 67 gallon Titan in my 450 while he did the same with his 350. He persuaded a local garage to become a Titan dealer.

Pricey..yes but the 450 is a young thirsty beast (only 7810 miles on the odometer) who needs frequent replenishment stops. I figured that I was wasting to much time sitting in line, actually fueling, using the facilities, checking out the newstand & goodies, walking the dogs, etc when stopping for fuel and my small amount of vacation time is at a premium.:mad:

At least this is how I argued my case to the keeper of the checkbook! :rolleyes:

12-29-2009, 07:50 PM
For us Dodge guys, you can do the vent mod on the OEM tank and get additional 5 gallons. That's about 65 more towing miles. I have also a 60 gal tank in the bed made to fit the space (L shaped) under the retrac bed cover. A lift pump to draw fuel though a water separator / filter and switch inside the cab and you're good to go. :)

12-30-2009, 09:41 AM
I have a 20 Gal tank in the front of my box. Its 12 Ga steel and been using it for the last 14 years. I have installed a gravity line to the fill neck that is on a NC solenoid valve that I control from the dash. I also have a 5 Micron filter between it and the truck tank with a bypass line. The tank is vented from the top to the fill line so it has the Regular truck Fuel cap as the vent for both tanks. The Fords have a Fuel flow warning system that brings the check engine light on if the full gauge do not move for 100 Miles or so, so I just dump for a while and then shut. By the time I am 1/2 tank on the truck gauge my auxiliary tank has emptied. I do carry a spare filter but so far in 3 years no requirements to change. My buddy has one of those installed Toolbox tanks, never used this summer and this fall he had water in the fuel problems, my tank is only 5 in thick by 62 inches wide and never had water problems in the last 14 years. Moisture is a problem if not used all the time, mostly here where we have big hot to cold swing in temperatures.

12-30-2009, 10:40 AM
Hey Jim, what is the Dodge vent mod?

12-30-2009, 12:49 PM
Hey Jim, what is the Dodge vent mod?

PJ here is a write up on that mod on another forum.

12-30-2009, 04:19 PM
I have a Northern tool in bed 48 gal tank/tool box combo - could not be happier . i put a "on-off" switch on my dash which also activates a fuel pump. works great. Prior to the fuel pump I could not drain out the last 7 or 8 gal. This is a nice staight forward installation . simple is good !

12-30-2009, 06:04 PM
I added a transfer flow 50 gal tank to my GMC. I installed it myself and saved $300. I have had it for 5 years without any problems.

12-31-2009, 01:00 AM
I have a 60 gallon tank in the bed. It feeds the OEM tank by gravity. I have a solenoid valve to control the flow. Like charliehorse said, the last bunch of fuel does not want to come out, so I plan to shim the off drain side of my tank a bit to get the fuel to flow to the drain side. That should do the trick. I do notice the extra 400+ pounds of fuel on board.


12-31-2009, 12:35 PM
When you use gravity feed it is very important to vent the auxiliary tank in the truck tank vent. That is if you would like to see the gauge going up, and empty faster.
Let me explain. When you open the dumpvalve , you allow fuel to flow in the bottom tank, and the bottom tank needs pressure to vent out. I connected a line from the fill neck of the truck to the top of the auxiliary tank so as to vent the bottom tank back up to the top tank. Now the bottom tank air escapes to the top tank while the top tank gets its vent from the bottom tank. The bottom tank cap is now the vent for both tanks and therefore you are covered for proper ventilation. This way I just cap the top tank off, let it vent through the bottom tank cap, that is also certified. Tank certification is mostly required for pumped tanks and not for gravity units as it is just an extention of the bottom tank.
My friend had a dump tank that just vented out and he had to stop and open his truck tank cap to let the air escape in order to empty the top tank.
With a 10 micron filter and Solenoid valve, I can empty the top tank everytime, at the lower level it empties slower but does it quit well.

01-27-2010, 11:18 AM
I am going to put an aux tank in my TV as well. has anyone dealt with ATTA in Texas? They have a real nice selection of aluminum tanks and their fuel transfer system is DOT approved. Not cheap but I was looking at the 30 gal to try and keep the weight down and still give me plenty of range.


01-27-2010, 11:41 AM
Check on RDS tanks also, Lots of different types and a lot less money. Jon

Terry H
01-28-2010, 01:05 AM
Yes, I bought one from ATTA, it is a quality product in every way. Easy to install. I live about 20 miles away and picked the tank up from their factory. Nice people to deal with.