ok I need to change the oil in my F20 4-stroke but noticed a local dealer, which I will never go to again, wanted like $20+ for just the tiny oil filter. Is this right? Is there another place locally you can usually get them? Also a friend of mine told me he doesn't use Mercury oil filters on his boat anymore since he figured out he can get one that fits a car for 1/3 the price. Is this ok, or is there something special about a marine oil filter? One more question, what is your guys perfered oil? do I have to use yamalube stuff, or can I go with a synthetic automotive oil?