I have 3116t cats and have a 41 Silverton and need to due some travelling. I'm told different stories on fuelconsumption. I'm in no hurry so would I have better fuelconsumption going 6-7 knots or going at speed required to get on plane. Manufacture is saying 2400 rpms.
6-7 kts is well below displacement speed for that boat, so it should use very little fuel, may be 2-3 gph. That may be too little for those engines to get up to operating temperatures. I would suggest 7-8 kts and burn 3-4 gph.