Saving boat gas.

BroadHopper · 06-17-2010, 10:32 AM

Did a search on this forum and I don't see a thread on how to save gas. So here goes.

Somewhere on my INTERNET search, I read, if you have a boat and get 10 GPH or better (less) you have pretty good boat. I'm wondering what folks are getting around the Lakes Region area. And what steps are taking to conserve gas, beside the obvious 'dock your boat'.

I have been experimenting with different props. My 1988 F223-LS with the 7.4 liter engine and Bravo drive originally came with a 19' SS 3 blade prop. I am the second owner. GPH at the time was 11. Since I was bumping the rev limiter at WOT, I decided to switch to a 23' SS 3 blade. This is the recommended prop for the 7.4 liter by Mercury marine. My GPH with this prop is 9 GPH. With light load and half tank of gas, I was hitting the rev limiter at WOT. I decided to switch to a 25' SS 3 blade. My GPH increased to 7.95 GPH. Since I was experiencing prop blowouts, I decided to switch to a 24' SS 4 blade. Blowouts are gone. I do not hit the rev limiter at light loads situations. My GPH slightly decrease to 8 GPH.

Bear in mind my average RPM is between 2500 and 3000 RPM. I normally leave with a full tank and 3 adults. The GPH readings are the average of several trips for each prop. At 2500 rpm my GPS speed is 30 mph.

By changing props, I save 3 GPH. A 37.5% savings.

Any other ideas to save gas?

06-17-2010, 10:32 AM	#1
BroadHopper Senior Member Join Date: Oct 2004 Location: Laconia NH Posts: 5,606 Thanks: 3,238 Thanked 1,113 Times in 799 Posts	Saving boat gas. Did a search on this forum and I don't see a thread on how to save gas. So here goes. Somewhere on my INTERNET search, I read, if you have a boat and get 10 GPH or better (less) you have pretty good boat. I'm wondering what folks are getting around the Lakes Region area. And what steps are taking to conserve gas, beside the obvious 'dock your boat'. I have been experimenting with different props. My 1988 F223-LS with the 7.4 liter engine and Bravo drive originally came with a 19' SS 3 blade prop. I am the second owner. GPH at the time was 11. Since I was bumping the rev limiter at WOT, I decided to switch to a 23' SS 3 blade. This is the recommended prop for the 7.4 liter by Mercury marine. My GPH with this prop is 9 GPH. With light load and half tank of gas, I was hitting the rev limiter at WOT. I decided to switch to a 25' SS 3 blade. My GPH increased to 7.95 GPH. Since I was experiencing prop blowouts, I decided to switch to a 24' SS 4 blade. Blowouts are gone. I do not hit the rev limiter at light loads situations. My GPH slightly decrease to 8 GPH. Bear in mind my average RPM is between 2500 and 3000 RPM. I normally leave with a full tank and 3 adults. The GPH readings are the average of several trips for each prop. At 2500 rpm my GPS speed is 30 mph. By changing props, I save 3 GPH. A 37.5% savings. Any other ideas to save gas? __________________ Someday may never be an actual day.