[davealves]

It all depends. What''s the weight of the boat, beam, prop pitch, etc. I have a 4-108 in a 40'' Jeanneau which displaces 16,000 lbs, two blade folding prop, 12''8" beam and I burn a bit less than a gallon an hour at 2,000 rpm (about 6 knots). Hope this helps.

regards
Dave