Just for fuel consumption reference, I calculated over 3 tanks of fuel this summer an average of 3.7 gph. That's a 99 ish GT-40, 310hp, with my 21' Bravura, nice new acme prop, 1.23:1 transmission. Always with people in the boat (from 2 people to 12), sometimes ballast, sometimes pulling riders, some idling, some 35mph all over the lake. Anyway it's a reference point, 3.7gph.