The engines have about 3,300 hours. I have owned the boat for the last 150 hours. And I keep track of gallons and time. That is how I get to the numbers I provided. The temperature gets to the desired number 175 to 180 during idle and does not increase even as I push up to 10 or 12 knots. I do not see a difference in operations other than fuel
Overall the design of the boats seems happiest between 8 and 10. It starts pushing water
It may be worth talking to Jefferson, additionally while it is tricky you can go on the Caterpillar web site and get fuel consumption
numbers for the engines. Are they turbo and to what degree. The more Turbo the higher the fuel at higher speeds but also the higher potential output.