fuel consumption on 31 TE with twins

[sharffj]

Know this probably has been dealt with before, but most of what I found was on 28's or single Cummins. Wonder if anyone has data on fuel consumption for the 31with twin yanmars 315. Have just put floscans on, but these will probably need some adjustment. Right now feel like showing too much burn rate per engine.
Thanks
Jeff S

[Albinflorida]

Should be 8 - 9GPH PER engine at 3500 - 3600 RPM, assuming you are turning 4000 WOT. Flo Scans should be calibrated once installed.

[zinbaad]

On the run to Essex last year running for the most part 3000/3200 rpm twin 315's burned 14,5 GPH. The only time running less RPM was on the trip from marina to the Sound. This may be off since having the port engine tach recalibrated in Sept which the mech said was off approx 100 rpms. Hope this helps

[sharffj]

Ran the boat from Portland Or. up to Anacortes Wa. over the last 3 days. Trip about 300+ miles. Down the Columbia ran at 3000 to 3100 rpm averaging 22kts getting about 1.3 mpg. Up the outside bucked into a stiff NW wind with a 4ft steep NW chop from mouth of Columbia River to off Grays Harbor Wa. running about 2800 rpm, averaging 16kts. After Grays Harbor ocean laid down and ran about 3000 rpm averaging 17-18 knts. Got about 1 mpg when filled in Neah Bay. Had to run into the ocean whole way up. From Neah Bay to Anacortes ran against the tide current up the Straits. Current was about 1.5 kts. Ran at 3200 rpm, averaging 19 kts. getting about 1.1 mpg.
All legs done fully loaded with fuel and water. Sounds like am getting less mpg than others. Had the tachs calibrated in Jan so should be on. And Floscans agreed with fillups to about 5% or less.

Any thoughts
Jeff S