I owned a 2005 228 with a F225 for three years and 550 hours. We usually ran the boat heavy with fuel, safety gear, water and ice and got a solid average of 2 MPG statute. If I was light, she ran at 2.2 MPG or so. When heavy, we cruised at 4,100 RPM's which was about 12 GPH and 24 MPH GPS statute. When light, is was more like 11 GPH at the same speed and RPM. All of this was "real world" on the ocean experience in varying conditions, calm, not so calm, windy, etc. We had the 228 with hard top + aux. fuel tank and a heavy T8 Yamaha kicker on the transom. Hope this helps.
