Running a tracker 1648 (2018) mercury 25hp. Original prop was 9.5x11 stock got 5200-5300 rpm and 22-23mph wot , mercury prop selector tool said use a spitfire 4 blade 9.3x11, took boat out over weekend always run 2 guys 2 batteries and trolling motor and fishing gear . 5800 rpm 24-25mph ...