Fuel economy-R-25 Classic

[Jmangiameli]

Hi all,

I thought I would post our fuel consumption numbers from our last trip.

We have a 2009 R-25 Classic with the 150 Yanmar. I very seldom break 8 knots and spend most of my time between 6 and 7 knots (old sail boater here-6 knots anytime I want and any direction I want is FAST)

The following numbers come from the Garmin

1. Total miles traveled: 301
2. Total Fuel burned: 77.2 Gallons
3. Total time underway: 46 hours

That puts my average speed over ground at 6.5 knots.

Average fuel burn at 1.7 gallons per hour

And a average of 3.9 NMPG

Best day (NMPG wise) was 50 miles at 4.8 NMPG and the worst day was 33 miles at 2.6 NMPG

 

[Levitation]

I'm an old rag bagger like you - I get a nosebleed at anything faster than 6

Fuel burn is high
My 2009 R25 burns from 1.0 to 1.1 gal/hr at 6 knots with the Cummins (depends on the wind)
Is your bottom clean
Maybe prop is bent or covered with mussels
Is there a zillion pounds of 'stuff' in the boat
Do you have a diesel heater running inside the boat

Now, fuel burn goes up exponentially beyond 6 because drag goes up exponentially
Going 7 will cost you a bunch more fuel than 6
Going 7 against a current makes it even worse (Like going 8 or 9)

I'm thinking that you are running faster than you think longer than you think against the current and that you are actually doing quite well

 

[ngleadow]

Blue Socks is a 2010 R25 classic with 150 Yanmar, and we get almost exactly the same fuel burn at 6.5 knots as you do.

 

[jcarrdive]

We, on the Bobolink R27, have a Yanmar and we burn about the following
5 knots .5 gph
7 knots .8 gph
9 knots 1.6 gph

That is our averages. Our best speed vs fuel consumption seems to be around 7 knots.
jeff and Ela

 

[Jmangiameli]

To Jeff and Ela

Are you really getting 7 knots with just a .8 gal fuel burn? Any one else doing that?


To Denny-O

I guess I should have said that I tend to cruise between 6 and 7 knots OVER GROUND. So yes, sometimes I am doing 9 knots through the water to make my 6 knots over ground.

Joe

 

[jcarrdive]

That is what the garmin is reading. I will revisit it again and document it absolutely.
jeff and ela

 

[Glen]

If my math is correct .8 gph @ 7 knots is equal to 8.75 nautical miles per gallon, that is much better than I'm seeing with my R-25 / Volvo D3 engine.

 

[Hydraulicjump]

On our R-27 with the yanmar there is a magic rpm: 1600. At that rpm we are burning 1 gallon/hour and make something in the vicinity of 6.2-6.5 kts with a clean bottom. But where we boat the tides are always ripping and the winds are often too so this figure rarely is achieved. On plane, at around 16 kts and 3600 rpm we are burning 6 gallons/hour.

As per the earlier thread about trawler speeds, this is what I like about the boat. For me, it's the journey and 6.5 kts is delightful. For my beloved, it's the destination, so hurry up (although I like the ability to either shorten the time to get to where you will fish or, when rough, put the boat on plane to reduce the rock and roll).

Look for the green tug anchored in McCovey Cove tonight for the Giants game.

 

[NorthernFocus]

On our R-27 with the yanmar there is a magic rpm: 1600. At that rpm we are burning 1 gallon/hour and make something in the vicinity of 6.2-6.5 kts with a clean bottom...

I was wondering when someone was going to bring RPM into the discussion. After all, RPM and/or STTW are the only consistent measure to evaluate fuel consumption. I wonder how commited this crowd actually is to trawler life. All this discussion about speed as measured by the GPS suggests a propensity to measure one's progress rather than watching the scenery go by...

 

[Boatagain]

<<Look for the green tug anchored in McCovey Cove tonight for the Giants game.>>

Be sure to get on top with a glove when Bryce Harper is up.

GO NATS!!!

Sorry, couldn't resist. 😳

 

[bluebayou]

As a longtime SF Giants fan, I am always watching for a Ranger Tug in McCovey Cove just past
the right field bleachers……..never.
So, apparently tonight we shall see a green R-27.
I am SURE this appearance of a Ranger Tug will clinch the Series for the Giants !!!

 

[Hydraulicjump]

And it DID! Go Giants.

Sorry to have hijacked this thread, but it is a kick in the pants to anchor out at McCovey Cove. And when that home run landed next to us, people jumped out of their kayaks, even their powerboats, and swam to fight for it. Being that it was a Nationals home run, they threw it back. Huh?

I recommend this tug adventure with enthusiasm. Dress warmly! The trip back in the dark with San Francisco all lit up and the New Bay Bridge span with its dancing lights is magic. Pure magic.

And more to come!

 

[Boatagain]

:cry:

There's just no substitute for experience. Congrats to all you Giants fans, sympathy if you love the Nats.