I was at the boat yesterday and  found the 

Paul Requested info- I've spent a reasonable length of time running at 1800 RPM and have a pretty reliable fuel consumption of my engines at that speed. But I don't have enough time at other speeds to make a reliable calculation. So, if anyone out there has Cat-3208 Turbo's (325Hp) and a chart of RPM-vs-burn-rate I'd appreciate a copy! Just as a point of comparison, at 1800 RPM, the twins manage to push my 90,000 pound boat along at 9.5 knots on 10 GPH. Paul Goyette Reply- I was at the boat yesterday and found the following information about RPM-vs-burn rate. The graph I found in my Defever manual referenced Caterpillar Data Sheets # TDO339-05 and TD3131-00 and is for the 375 HP version of this engine. Test conditions at 77 F temperatures and 29.61 inches of hg barometric pressure were used and fuel oil weighing 7.1 pounds per gallon and rated at 19590 BTU per pound. RPM GPH 1600 4.5 1800 5.2 2000 6.9 2200 9.5 2400 12.1 2600 16.0 2800 21.1 I can add my experience on CHATEAU covering the last four years. The boat is a semi-displacement full keel 46 ft vessel weighing about 35000 pounds and we normally cruise at 8,2 to 8.4 knots. These numbers have been gathered after 17000 miles of cruising and over 2000 engine hours with an additional 1400 hours on my 8 KW Onan generator. The two Cat 375 HP engines and the Onan are supplied from the same tank so my engine consumption figures can not be exact. To attain my normal cruising speed I run the Cats at 1200 to 1250 RPM with a total fuel burn (including the generator) of 4.25 gallons per hour. If I were to back out the estimated consumption of the generator I feel comfortable saying that each of the Cats burns about 2 GPH at my normal cruising RPM. I hope this info helps with your cruising plans. John and Karen Siscoe M/V CHATEAU Defever 46 POC Sports Cruiser Verizon Cell 813 951 3610 John Cingular Cell 813 765 6660 Karen Currently in St. Pete Beach