I just purchased a auxiliary fuel tank for my truck that has a 26 gallon factory tank. Since it is for gas I have to pump it to manually, but the company I purchased it from is working on a transfer system for it. I got it from ATI who has a special certificate that allows you to transfer gas legally, which most tanks do not. It was much cheaper than transfer flow. Their website is www.atitank.com
. Worth a look if you are considering an auxiliary tank. Oh, and you can buy from the factory, but it is cheaper to buy from a reseller. If anyone wants to see pictures let me know. Oh, and it fits under my tonneau cover with the pump attached.