In article ,
Messing In Boats wrote:

I have a boat like that with a similar powertrain. I get 1.3 nautical
mpg at best on plane (20 knots) and 2.3 nmpg at best at hull speed (6
knots). I use this boat 150 to 200 hours a year (mostly at 6 knots) and
buy a bit of gasoline. If/when I repower, I will probably go back to gas
because the motor is so much cheaper, it will bolt right on without any
modifications, it's quieter and I can buy a lot of gas for the
difference in price. ($10,000)

One issue for me is range, which would be better with the diesel, but I
have an auxiliary tank.

Capt. Jeff


??? I would have expected quite a bit better mileage at displacement
speeds, not less than double.

Then again, what size powerboat (LWL) are you doing this with? As I
recall, the original poster was about our size (28' loa, 22' lwl). Could
you be just at hull speed at 6 knots indicated? On our diesel sailboat,
we get about 7 nm per gallon at hull speed (6.6 knots) and 22 nmpg at
85% (5.8). Quite a difference for about a knot difference in speed.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
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