Seamaster 27 Performance

[3rdday]

I have a Seamaster 27 Flybridge with a Bravo 1 outdrive, Mercruiser 454, and a 15 pitch Power Tech prop. I am looking for better cruise mpg,cruise is at 2800-3100 RPM and 17-19 mph. I contacted Power Tech and they tell me this prop was designed for load pushing, workboats, pontoons, etc. It is a 3 blade large petal shaped prop. I believe 15 is not enough pitch, what do you folks think? Power Tech recommends 4 blade with more pitch;; ""OFS4-Blade Offshore Propeller: Has a constant 15.25 inch diameter regardless of pitch, available in every inch of pitch from 14-30. It has a polished finish, right- or left-hand rotation, moderately high rake, full tip cup for excellent lift and grip. It is excellent for V-bottom Off-Shore style boats; single, twin, triple and stern (I/O) drive applications.""