I have watched quite a few YouTube videos on winterization. One in particular stated that the creator of the video called a professional shop in northern Minnesota. Who told him they drain the antifreeze out of the engine after a thorough A-F flush out. I think either way should be fine is there a preferred way? Maybe it is because it is much colder in N. MN. Than the S. KY area. Where my boat will be stored. New to boating just shooting for the preferred method.