Gallons per hour

[Dave R]

Originally Posted by BroadHopper

Just checking on what everyone is doing to save boating gas.

Normally I burn from 8 to 11 GPH on my 1988 223LS with 454MAG. I rebuilt the carb and leaned it a bit. I replace the oil with a thicker semi-synthetic. I also replace the 21" pitch 3 blade SS with a 20" 4 blade. I notice a 1 GPH average savings.

This year I played with the trim tabs and the power tilt so that I can maintain a plane speed of 25mph. I gain an additional GPH. I'm happy with the 6 GPH.

Any more tricks, other than stop boating?

MPG is the only way to know if you are saving fuel; you can burn GPH when sitting still. My last boat had a 454 and 24 degree stepped hull. My MPG peaked at 2.7ish MPG between 30 and 40 MPH. It was substantially worse at around 2.0 MPG (if memory serves) at 25 MPH and got around 2.2 MPG between 40 and 45 MPH. Slowing down a planing hull boat is not always the best solution for economy. That said, if I run my current boat on plane at a 20 knot (23 MPH) cruise, it currently costs me 7 bucks per nautical mile, if I run at 8.5 knots (10MPH) it costs me 2 bucks per nautical mile. Guess what speed I run...