Auxiliary Tank Combo

RDS 40 Gal/Tool Box, low profile so it fits under my Roll-n-Lock cover

https://www.deezee.com/product/combo-transfer-tank-brite-tread/

This is the one I have in my 21 Ram 3500

I have a 50 gallon trax 4 transferflow tank in the back of my dually. I have a long box. It's computer controlled which means it fills the main tank when it uses a few gallons and there's a gauge which sits on the dash and it tells me the total in both tanks and how much fuel has been used and when the tank is pumping into the main tank. . Mine is diesel. I had it installed 11 years ago and it is working like new. It fits under my tonneau cover as well. No tool box. With the main tank holding 36 gallons, I have a total of 86 gallons of fuel.

RDS 60 gallon with the tool box combo. One of the best upgrades I have ever done to a vehicle.

I also went with the RDS, mainly because I wanted a low profile tool box - fuel tank to fit under my tonneau cover. Holds about 40 Ga.

I use an RDS, carries about 44g and a 6" deep tool box up top. Got the kit that ties into the filler neck. No problems after 10 years.

I'm kind of looking for something for my Ram. I have a Weathertech tool box, but no auxiliary fuel tank. At the present time I'm using 2 5-gallon plastic fuel cans in the tool box. I don't carry much in the way of tools, so I've got lots of room. My old truck had a 35 gallon OEM tank, and a 35 gallon auxiliary tank. The new truck has a 32 gallon OEM tank, which is a bit small. I hate truck stops, so I prefer to fuel up without the 5th wheel attached. We rarely travel over 300 miles in a day any more so the OEM with the extra cans works...but barely. I'd like to have a bit more cushion, and an easier refuel than the fuel cans.