I read a post a couple pages back about oil additives and some people disagree about using them. They named one in paticular that I have never used but one that I have is Sea Foam but only in the gas tank and it seems to help for me. The manufactuer claims all kinda uses for this product including gas tanks,crankcases & for use in injector cleaning machines just to name a few. I'm thinking of using it in my engine this spring when I change the oil to see if it might help to clean up the valves a little bit but I'm not sure. Just wondering how many of you has used this and in how many ways. And does it seem to work?