Jeff it’s the same with the Honeygirl (well when it’s in the water and running) I have a sweet spot when the boat gets the best fuel economy. Sometimes it better for me to do 23-24knotts than to do 17 or 18. For you guys with out a fuel monitoring system they are worth there weight in gold. It will pay for its self very quickly and they are not the hard to install just takes a little time and patience.