I run on biodiesel produced from a biopro 190 automated processor. I do a titration, add oil and chemicals, come back 24 hours later and drain the glycerine and start the wash cycle. 24 hours later and I have finished fuel. I have about 15 minutes hands on time per 50 gallon batch. As for filtering and dewatering it all depends on your source of oil. My oil is water free and good quality. As for filtering, time is better than any filter or centrifuge. By letting your oil settle for at least 2 weeks, the majority of the crud will drop to the bottom. However, you must still filter your oil, your filters won't fill up as quickly though.

I started to go the WVO route, but biodiesel is the better choice for me. No modifications aside from a few fuel filter changes in the beginning and keeping an eye on fuel hoses which should be done anyway. Essentially you don't want to pay for your oil. There are enough small independent restaurants out there that are willing to work with you. I have never paid for oil and don't have any intention of doing so. All in all my costs are $0.77 per gallon of biodiesel.