Big Optimax get good mileage on a bracketed center console.
http://www.wellcraftv20.com/communit...ighlight=250xs
I can get up to 5 MPG. But that is in near perfect conditions and a very light load running on a river. Worst mileage to date was with the 24p Tempest hauling 10 people off the scallop grounds last weekend. Dropped back to 3 MPG. Made the little 250 grunt a little. It isn't propped to haul that kinda weight. Cruise at 4000RPM at about 30MPH on GPS.
Figured on 60 gallons useable, driving civilized, the range is from 180 to 300 miles depending on the load and conditions.