I am looking at getting an external fuel tank (the kind that gravity flows into my existing tank) I have a few questions.

1. We are looking at 5th wheels and bumper pull toy haulers. Having a megacab am I able to put a small tank in the bed and still pull a 5th wheel? If it's under the rail?

2. Can you attach pictures of your set up and tell me who makes it, and what you think about it? Is it just what you wanted or do you wish it had/did something else.

3. Do you think it's worth it to do an external tank if it's only 30 gallons? The one I'm looking at is the length of the cab and 9 inches wide and has a small tool box on top. We will be doing maybe 8 trips a year towing, no more than 1K miles away and in most cases only 300 miles (yuma sand dunes)

I've searched every thread on this site and am looking for more info. Thanks.

 

As long as it's under the rail it'll be good.

I went with an OEM tank replacement, because I wanted the bed open for more carp to drag along while towing the fifth wheel.

30 extra gallons is great. I went with my tank so I would have about 60 gallons range with a little reserve. Even if you're only getting 10 mpg towing, 600 miles is a good distance to tow between fill ups. So the tank PLUS the tool box is worth it for towing.

 

LV Tony. Do you have any pics of your tank? Thanks for the response. Anyone else?

 

Just worth a mention, but I think some state DOT rules don't allow for connection to stock tank from bed location(ie gravity drain), most likely due to possible rollover fuel leakage. Apparently if you carry fuel and pump it in w/o permanent connection it's acceptable. So you may need to get creative with plumbing(if traveling thru those states. Not sure which...be careful and good luck! :-)

Here is a link to an auxiliary fuel tank manufacturer's website that explains some of the reg's:

http://www.transferflow.com/fuel_tank_regulations.html

Scroll down to 'Refueling Tank Information'. Of note would be #6. 'No hoses may be attached to discharge outlets during transportation of TFI refueling tanks unless approved by your state’s highway patrol. No TFI refueling tanks may be manifolded together. No modifications of TFI refueling tanks are allowed.' (TFI being the manufacturer, Transfer Flow Inc.) Also of note further down is 'Miscellaneous Notes' and here is #2. 'When an auxiliary system is added to a gasoline powered vehicle, the fuel must be drawn through a pipe at the top of the tank. Balance lines or tanks in series so that one tank supplies another is not permitted. Gravity feeding from one tank to another using a balance line is illegal for all systems except ICC diesel systems.'

I believe the ICC reference may be for the fuel tanks on big semi's, so as to allow the gravity-fed crossover lines between side tanks, but seems to rule out utilizing bed-mounted tanks above the original tank for gravity feed doesn't it? Far as permanent connection I mean. Also may be helpful(or more confusing!) to review FMCSA(Federal Motor Carrier Safety Administration) rules 395.365 and 395.367 for further. Better safe than sorry, eh?

Like most things, I'd think some of these reg's would apply while others wouldn't, right? Also not trying to be the 'external tank police' or anything here, just thought it might be worth knowing about ahead of time.

 

No pics. Not really anything to see since it replaced the OEM tank. I went that way to keep the bed clear. Here's a link to a pic on the manufacturer's website: Aero Tanks

Having an extra 30 gallons is great when towing. More would be better, but 30 is enough to make it worthwhile and the toolbox will be nice.

 

OK, I have an 06 CTD Mega Cab. I'm adding a transfer flow 50 gallon tank in the bed. I was going to opt for a 30 gallon tank, but the fill neck extended above the bed rails which would have prevented me from having a tonnau cover installed. So I'm getting the 50 gallon tank. It fits below the bed rails. They are a little pricy, but the engineering is their. Check out their website.

 

The thing I really liked about this tool box combo was the fill neck was in the toolbox, so if you were looking from the outside you wouldn't know it was a gas tank. That is with the lid closed.

I did an extensive search before posting this questions and if I remember the thing with DOT was if your external tank and factory tank totaled more than 100 gallons then it was illegal. I think California was the only state where the law was different.

LV Tony, why did you go with Aero Tank? I like the idea of having my bed open, I just want to pay big $$$ for only 30 extra gallons.

 

Got mine at Northern Tool for 400 plus shipping. Need a rollover valve for another 70. Holds 37 gallons , made out of aluminum diamond plate.
Sorry don't have a picture since it's out of my truck while waiting for my new one to arrive.

 

Northern tool is actually where I've been looking. I assume because you are pulling it off of one and into the other you've been happy with it?

If I only filled the aux tank up when we went on a trip (8-12 times a year) will it hurt anything being empty for such a long period of time? I live in AZ so it's very dry here, if that matters. Thanks.

 

Yea I've been happy with it but only had it a short time and for one 2500 mile trip. It's nice not to have to fuel up every day , and you can chose where you want to fuelup. I don't know why it would hurt anything if it sits empty for awhile but I intend to keep it full when the prices are right at home.

 

...Then again, take a look at this complete refueling setup from the same company(Transfer Flow Inc).

http://www.transferflow.com/express-ufs.html

It appears to have all the necessary fuel lines/plumbing, pump, automatic refueling and all. 70gal, and reasonably priced too(as it seems to have everything included). Not pretty as toolbox/tank combo either. So on the one hand some DOT restrictions...on the other, well here's a factory-built kit, take your pick!(I'd go along with the kit, wouldn't you?). Please continue to update us all on your experience, will you? Thanks! :-)

 

That thing is a monster. I would like to have something with 70 gallons but I need as much of the bed as possible. The smallest one I've found is 9 inches deep and the width of the cab and holds 30 gallons. I'm surprised more people don't have these, or maybe they do and aren't responding.

I plan on doing this over the next month or so and will post pictures when it's done.
Thanks.

 

Well, the only reason I don't have one yet, is I can't find anyone who makes one that has a REAL toolbox on it. NONE of the tool/fuel kits have a toolbox that is much more than a shoe box IMO.

I also don't like the fact that it is all below the bedrails. If they made one that came up over the rails like a regular bed tool box does, you could have a decent tool storage section and still get plenty of fuel in it.

I'm having to resort to a custom made one that is pricey just to get what I need. It seems all the ones out there are made for trucks that need the clearance for their trailers.........I don't, and would much rather have the extra tool storage space.

 

I found one that had a sort of real tool box, I'll have to stop by the shop again becuase I can't remember the name. It was at least 24 inches deep and the entire width of the truck. Most of the ones I looked at were 12 inches deep.

 

I didn't look around too much. Most of the tank options range from $580 to $1300. I narrowed it down to a replacement tank, if it had enough capacity, so I could put my generator in the bed (it won't fit in the trailer basement). That made the range about $880 to $1200 for 59 to 75 gallons. Aero Tank has the highest capacity replacement tank at 75 gallons (for a long bed quad cab).

The Aero Tank can't be run down as far as the OEM tank, since the Aero Tank is flat on the bottom and the OEM tank has a curved bottom to provide a sump, so I try to fill up after using about 60 gallons (fuel gauge just above 1/4 mark), so I have a reserve. Just driving around town, this turns out to be about every month (870 to 900 miles). I'm hoping the Smarty on #1 will bump my MPG up to 15.5 to 16 in the city (~25% highway).

While towing my fifth wheel, I get around 10 MPG. I'm pretty happy with a 600 mile range while towing. I could get better mileage while towing if only I would drive slower, but it sure seems dangerous here in the West to drive too much slower than traffic.

Sorry for the long reply, but the mileage while towing, plus the generator, were all grist for my decision process.