Mainship 30 Pilot II fuel use by the numbers
We just got back from a 244-mile round trip over the last few days, our first trip beyond 20 miles from home in this boat. Our former boat was a Grand Banks 42 with twin naturally aspirated 120 HP Ford-Lehmans which I ran at 1600 RPM for 9.5 MPH over my 29 years of ownership averaging 2.5 MPG (3.7-3.8 MPG); so I have been interested how this faster, lighter Pilot II would perform with its vastly different turbo-charged Yanmar 315 HP engine.
The first thing I did with this Pilot after I bought it last June was to add a calibrated fuel level sight gauge like the ones I had in the trawler. Level measure tick marks are in 10-gallon increments.
Thanks to the kind soul who posted the Yanmar-provided fuel usage data for this boat and engine, I was able to make up an Excel spreadsheet with as graph including MPG, GPH, MPH, and knots all versus RPM which gave me a starting guesstimate and proved surprisingly accurate.
I this bi-directional trip ran in one direction at 3100 RPM getting 19-20 MPH and in the other direction at 2700 RPM getting 14-15 MPH (almost 16 for a short period with a favorable tide). At 3100 RPM I used 9.2 GPH, and at 2700 RPM, I used 6.5 GPH. These numbers compare well with my graph; so I will feel comfortable in the future using it at the helm when I want to know what to expect for fuel usage.
What really pleased me was to find that fuel economy at 15 MPH and 20 MPH were respectively 88 and 72 percent of the "economical" trawler while running respectively 58% and 110% faster.
FROLIC (2005 MainShip 30 Pilot II)
Panama City area