Perhaps I'm nuts, perhaps mad as a hatter, perhaps a genius! So, I want the best of both worlds, an aux diesel tank and a slide-in camper. But wait, I have a new body style truck. I have to use spacers (3"-4") between my truck's bed and the camper bottom. That's a lot of lost space. Seems to me one could fab an aux tank that fits the bottom of the truck bed, if heavily baffled (meaning reinforced for weigh bearing), that would pull double duty as it would raise the bed height, thus alleviating the need for spacers. Aluminum construction, with a thin rubber bed liner on top. How much fuel could you carry? Let's see, 8' x 4' (which doesn't take into account the actual larger footprint available due the hour glass shape of a bed) x3". So, conservatively, that's 60 gallons. I think I have a potential Summer project.

Sounds Heavy. Sounds Expensive. Sounds Unsafe......

Sounds like a great idea, you can never have enough fuel capacity...... Since you have a diesel truck it will be safe, but its not so clear for a gas engine. There are lots of truck bed auxillary diesel tanks out there, you can tie them into your truck's fuel system too just follow all the safety regulations. As for gas, you can have an auxillary tank but it can't be tied into your truck's fuel system.

60 gal of diesel will add 480lbs then there's the weight of the tank (100lbs??). So close to 600lbs extra weight in the back. If your truck is like mine you'll have plenty of room on the rear GAWR but may sqeak by on the GVWR. I'd goto your local scales and take some measurements with the camper on then factor in the extra 600lbs and see where you stand before starting the project. It sounds like a lot of work to build the tank.

FYI, diesel is 8lbs per gallon, water is 8.5lbs/gal. So make sure your fresh water is full when you take the measurements too or factor in the water's weight later.

Supporting a 2000 lb. (+) camper on top of an alumninum tank is NOT a GREAT IDEA...

Ended up with a 65 gallon aftermarket tank installed in the factory location. Expensive, but worked fine.

Another thing you would have to keep in mind, no matter how well baffled it would have to let fuel move. If you had half a tank then when accelerating or going up hills you would have 30 gallons of fuel going all to the back adding 240 lbs. behind the rear axle.
That could cause some strange handling as it unloads the front end.

Rick

Auxiliary fuel tanks must be DOT certified. You may never have a legal issue but if you were involved in an accident your insurance company may refuse to pay the claim.

Wow, back from the dead. Went wituh a 65+ gal Aero underneath.

why do u have to space it up 3-4 inches??

The camper will hit the top of the cab on a Ford due to the height of the cab.