I'm not confused at all about the difference btween biodiesel and WVO, quite a few other people are though. Quite a few people think biodiesel=WVO, they don't understand biodiesel is WVO that has been altered chemically and is no longer WVO.
I have no problem tracing a WVO system out and understanding what does what as long as the customer is willing to pay me for my time. Its when they don't want to spend the money that I have a problem with. Here is a description of all the WVO systems I have seen come into shops I work at. Usually they have a van or motorhome that they are living in and don't have high standards of hygenie. The first thing that hits you like a brick is the smell, then you stick your head inside to see if its as bad as you think, usually it is. You fight the gag reflex as you pull the doghouse off to access the rear of the engine, usually you have to move a bunch of crap to do this. You haven't lived until you work on something that has crap, trash, and God knows what in it for God knows how long. You try to hurry as quick as you can, by the time you are done your skin is crawling and you feel the need to take a shower and change into clean clothes. This is why I say I have never seen a good WVO system, I know they are out there, I just have never actually worked on one.