1972 Seafari, 2007 150 E-TEC, Potter/Hermco Bracket; motor raised 2" from original setting (Cav. plate 2.5" above keel for 2.5' bracket setback + 2" = 4.5" above keel currently)
Boat has trim tabs, Doelfin on cav plate.
With Michigan Apollo 4B SS 14 1/8 x 20" pitch Prop:
Optimum Cruise: 2800 rpm/23 mph(GPS)/4.4 gph/5.2 mpg based on Floscan/BRP I-Command digital gage system
Max 5100 rpm/49.9 mph
With Michigan Vortex 4B Alum 14x20" Prop, same motor height:
Optimum Cruise: 3200 rpm/26.5mph/5.0 mpg
Max 5100 rpm/46.1 mph
The E-TEC's run a VERY lean stratafied charge system below 1000 rpm so mileage at ~ 5 mph trolling speed is 8-12mpg depending on current. Thought it would be interesting to look at total miles/fuel burn for both props to get a feel for true average mpg.
4B Alum. Prop: 175 miles/37.6 gal/4.7 mpg
4B SS Prop: 315.4 Mi/62.2 gal/5.1 mpg
Figured out that with gas @ $3/gal, I'll only have to burn another 480 gal to pay for the $360 stainless prop!
