Don't want to open a can of worms here but.... I am looking to change over to a full synthetic oil and need some advice. I read somewhere, maybe here, that the best way to change is to slowly do the switch over 2-3 oil changes. In other words, part synthetic and part dino one time then more synthetic and less dino the second change then all synyhetic the third change. I don't understand the logic of doing so. Secondly, I live in Michigan so in general my riding is not in extreme heat or cold. Any suggestions on brand and viscosity rating for my climate? As long as we're at it, any good filters that I can get at any auto parts store?