My X45 L18 with 14.75x17.5 is at about 3200 rpm at 22mph. I'd like to improve fuel consumption, so assume lowering rpm would be helpful. Wakeboarding is primary usage, and its about 3000rpm for 22mph with no ballast. I've got open tips with silentmaster, and 2009 ECM that more matches this config. Maybe this solved the issues that made 2007 and 2008 not be able to use the prop you developed for the 2006 L18x45? I don't want wakeboard out of hole to suffer, right now the boat does amazing acceleration, but the rpm's and gph seem high.