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Old 05-02-2011, 11:51 PM   #11 (permalink)
Join Date: Oct 2009
Location: South Central AK
Posts: 933

escort - '99 ford escort sport
90 day: 42.38 mpg (US)

scoobaru - '02 Subaru Forester s
90 day: 28.65 mpg (US)
Thanks: 32
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when you are running there will be a most efficient indicated speed. Some speed up or down from that depending on what the current is doing will yield the best MPG so some GPS information would be useful but a close enough approximation can be made just by knowing the current speed which can be learned by looking at it. Drifting down stream will be 999999999mpg but that is not useful information.

The OP already has a speed sensor. That will give a good deal of information if the signal is compatible, if not *shrug* the speedometer with knowing the GPH is nearly as good.

Increasing speed over that needed to be on plane is not likely to increase MPG. Yes there is less hull in the water but the force needed to lift the weight of the boat up on step is the same at 25 as at 50mph. The smaller contact area is doing the same lifting by hitting a smaller number of water molecules faster so the drag is about the same. Increasing speed will increase the amount of drag from the lower unit.


Learn from the mistakes of others, that way when you mess up you can do so in new and interesting ways.

One mile of road will take you one mile, one mile of runway can take you around the world.
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