About 15 years ago, there was a guy in central Illinois that lived out of his diesel van. He was running WVO in his van. He had a small tanker trailer, maybe 150-200 gallons, that he drug around with his van to all the restaurants and collected their discarded oil. Everything was processed on the trailer with a final filtration occurring in the back of the van through a floor to chitterling filtration rack with heaters before going into his main fuel tank. He had what appeared to be heavy duty hydraulic hoses with quick disconnects that went from the trailer to the final filter rack in the back of his van that he only hooked up when the truck was stopped at a pickup point.
Unfortunately, he was in his late 60s early 70s then, and he passed away a couple years ago. He was an 'icon' in Decatur, Illinois because he was doing this on principle alone. Apparently he was a millionaire and diesel prices were still low at that point in time. He did it to prove a point.
So, it can be done if you put your mind to it, but remember to ensure you can sample the processed fuel before it enters your truck's stock fuel system so you can at least keep an eye on things, and I would recommend a portable 'dike' to put around your setup to ensure that if their is a spill while you are processing 'on site' that it is contained.