If your getting waste veggie oil from a local restraunt it should be fine. You'll have to do a titration test to determine if it's usuable. Motor oil could be made into fuel, I don't know how but it wouldn't be considered biodiesel. Biodiesel is the transfercation of oil bonding with methanol with the bad part of the oil going out with Lye or potasium. This site http://biodiesel.infopop.cc/6/ubb.x?a=cfrm&s=447609751 is very informative do some reading and you'll figure it out. It's not hard, I made 20 gals perfectly the first time i tried, but I read for about 4hrs.