jbinbi
Senior Member
I am coming from a sailing cat that had dual engines. When in the harbor for maneuvering, you use both engines and can do things I never dreamed I could do on previous monohulls. Having 2 engines 16' apart was just amazing.
However, when motoring on a passage, you normally just use a single engine. With both engines I could drive at say 8.5kts at WOT (2 gph). At about 7.2 at 2800 (1.5 gph). With a single engine I could do about 6kts at 2200. That was about 0.5 gph on my yanmar 30 hp. You just slowly pull back on one of the throttles over the course of a minute or 2 to let the AP adjust the rudders slightly for the single engine. So you use 1/3 the fuel to go from 7.2 to 6 kts.
On monohull powerboats with dual engines, can you do the same if trying to run at under displacement speeds?
However, when motoring on a passage, you normally just use a single engine. With both engines I could drive at say 8.5kts at WOT (2 gph). At about 7.2 at 2800 (1.5 gph). With a single engine I could do about 6kts at 2200. That was about 0.5 gph on my yanmar 30 hp. You just slowly pull back on one of the throttles over the course of a minute or 2 to let the AP adjust the rudders slightly for the single engine. So you use 1/3 the fuel to go from 7.2 to 6 kts.
On monohull powerboats with dual engines, can you do the same if trying to run at under displacement speeds?