315 Yanmar fuel burn

[ljmauricio]

I am considering a 31 FBC with 315 Yanmars. Seller claims 26 knt cruise. Can someone with those engines give me an idea as to the fuel burn at cruise. I sold a gasser with Crusaders several summers ago because it was too expensive to run. (.75 mpg at 21mph when gas was $5 on the water) Thanks for any responses.

[Yannis]

My 28 with 240's burns 2.8 liters per nm. at 3000rpm at 24-25 nm cruise.(wot 3300)
My friend's Albemarle 31 with 375's, burns more like 4 liters per nm at 26 ish cruise, Im not sure about rpm's.(wot is higher, I think 3600?).
All readings in nm, not street miles. Although this is not exactly what you asked, I hope it helps.

[Tony Meola]

I run Cummins but that ,36 knot cruise is about right. In fact you might be able to push that up a bit depending on how heavy the boat is.

Y
I would guess fuel burn is between 15to 18 gallons an hour. So figure with the higher cruising speed and even st 18gallons an hour you probably cut you fuel burn by close to half.

[Yannis]

Tony, youre spot on, its like 16-17 gh, the part with the speed I dont get...ffmghy lol !

[Priceless]

I've got a 71 Bahia Mar with twin 315s. Did a bunch of work on her and probably added 1500 lbs. running 1.5 to 1 gears and she cruises at 3100-3150 / 26-27 kts, wide open 3850 / 33.5 knots. Fuel burn at cruise is 12-13 gph total. Even I can't believe it. If I keep her at 2800 where the previous owner liked to run economy is even better but 22/23 knots is kinda slow.

[Tony Meola]

Yannis I go back to a desk top tomorrow so no more note pad corrections or my fingers being too fat for the keyboard.

[Yannis]

Tony, its not 36 but 26 knots. Thats why it puzzled me for a while.

[Craig Mac]

Priceless---what props are you running?

[Priceless]

18x20 three blade nibral said on 1 3/8 inch shaft