I was out this weekend and my boat ran better than it ever has in its life. It was about 55 f outside and water temp was 54 f water was realy choppy to.seems like i get more speed when water is a little rough not real rough.and motor was realy running good sounded great and rpms were up is this do to cool weather? boat always runs good just seemed to preform better these last two days.I did change impeller before I went but wouldnt think that woul give better preformance? thanks.