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Old 09-21-2015, 12:50 PM   #10
FF
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Join Date: Oct 2007
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"Is that a standard formula for optimal fuel burn?"

Close the sq rt of the lwl times .9 to 1.15 is the most common speed sweet spot.

Fat heavy boats will go slower than the lighter skinny ones, but as a simple rule of thumb, its fine.

Note it is almost IMPOSSIBLE to set up a boat cruise with good efficiency with out a fuel map, or BMEP graph.

It would take a flow-scan EGT gauge , GPS and a dozen prop swops to figure out the info the mfg usually refuses his customers.

The usual power and prop graph assumptions will not do the job.
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