I have. 1993 SeaRay Express Cruiser...

[Will_G]

I have. 1993 SeaRay Express Cruiser 400 with twin diesels.  Anybody else with one I would appreciate information on fuel ranges/economy.

[SeaMax]

I have a 2000 410DA with 3116 Cat Diesels. Not the same boat but similar, I don’t keep track in terms of MPG due to the many variables. What I do measure is the GPH used from fill to fill and that is 7.6 gph which covers both slow and high speed cruise.

[gtstang462002]

Lacking details of your boat, but to give you an idea. My boat is 46' at the waterline, weighs 41000 lbs in the sling and is powered by 6v92 detroits rated at 550hp per motor. When cruising at 20 knots I am buying about 38 - 40 gallons per hour. Mix some trolling and low speed cruising in there and that drops back to 14-18 gph. Hope this helps a little for general planning. A clean bottom always helps to burn less fuel.

[Dave_F]

It is all about speed. Low speed cruising at 6-8 knots should give you around 3 to 5 nautical miles per gallon but up on plane you will see that go down to 1/2 to 3/4 nautical miles per gallon. As mentioned, a clean bottom makes a big difference as well as excess weight with full fuel, water, and a bunch of people on board.

[Seaclusion]

I have a 2003 410 Sundancer that's gotten almost exactly 1 mpg average over the last five years. I suspect your mileage will be similar.