I read some posts which compare fuelconsumption for number of engines used ...
I have done extensive research on our vessel now having covered 2 years at sea over large distances (Cape Town to Raiatea) and must say I have found the following link to be exceptionally accurate. I like statistics ... especially the ones I have tested for our specific environment ... you may find the web below helpful ...
When we powersail .. only ever one engine and at slower speeds. On the Yanmar cone clutch saildrives I have a hunch that a prop ticking over when windpropulsion is higher than that of power causes resistance on the prop and wears the cone clutch pack. As I say ... a hunch ... and I certainly am getting more hours out of my cones applying this theory.
Oops ... seems the link does not work that well ... can also just google Twixter FuelConsumption and it will bring the spreadsheet PDF download up
Your boat is 33 feet and you say it takes 15 liters. You said it takes 60 liters for a 40 foot boat.
So it takes 45 more liters to do the extra 7 feet beyond the 15 liters needed for the first 33 feet?
Again, we have been painting our 40' catamaran regularly for 15yrs and it takes 11 liters for 3 coats. The difference is most likely that we have less underwater area than you. That is why I suggested your boat may have the underwater surface area of a newer 45' boat.
But 60 liters is way out of the ballpark for a 40' catamaran.
point taken, maybe i am too generous with my paint! to stay with the thread of this forum, a catamaran that can dry out easily, I regularly drive it onto a sandbank tide allowing and clean it, will be clean all of the time, making it sail better more efficient so also problemless motoring with one engine
Hi we have a Crowther 50 with twin Yanmar 54hp sail drives and feathering props we motor at 7.5 to 8 knots using one engine at around 2800rpm and flat out 11knots with both
Only use both berthing or anchoring