Bryan wrote:
For those of you who have used the fuel flow meters what do you think about
fuel efficiency?

For a planing boat, which is more efficient, motoring at 3-5 mph (no wake)
or motoring at the lowest speed that allows the boat to plane?


No question there, the best fuel efficiency for distance
travel is usually at (or just above) idle. But who is
willing to actually travel at that speed?


Is the lowest speed that allows the boat to plane the most efficicient
planing speed or is there a sweet spot somewhere between planing and WOT?



It is possible to make some generalizations, but most people
reject them because they really prefer to believe otherwise.

1- For a given hull & load, as speed increases, fuel
consumption increases exponentially.

2- For very light & very flat hulls (ie hulls that are easy
to lift and generate a lot of lift), the fuel penalty for
planing is not as severe... for some extreme examples, the
particular boat might actually get better mpg while planing,
but this is quite rare Only for very light, very fast boats
can achieve this.

The corollary to #2 is (of course) that heavy deep-vee
hulls, loaded hulls, "semi-planing" hulls, etc etc, are
going to get very poor fuel efficiency. But fuel has been so
cheap, who cares?

Fair Skies- Doug King