17.2 gph average for first two tanks - 2000 410DA 3126 CAT

I just topped off my tanks about a half hour ago. I ran 179.5 miles in 18.2 hours since 6-6-12. approximately 80 of those miles were on plane in the Atlantic Ocean to/from the LL Rendezvous. I'd guess 50 or so of the remaining 100 miles were on plane and the other 50 were at or below hull speed. I took on 170.2 Gallons. That's 1.06 sMPG and 9.35 GPH.....all numbers are "AVERAGE"...I don't have flo-scans.
 
I ran 700+ miles to NY and back and put $4500 on my credit card. That is an average $6.43 per mile just to come and see youse guys...how 'bout them numbers?
 
I just topped off my tanks about a half hour ago. I ran 179.5 miles in 18.2 hours since 6-6-12. approximately 80 of those miles were on plane in the Atlantic Ocean to/from the LL Rendezvous. I'd guess 50 or so of the remaining 100 miles were on plane and the other 50 were at or below hull speed. I took on 170.2 Gallons. That's 1.06 sMPG and 9.35 GPH.....all numbers are "AVERAGE"...I don't have flo-scans.


Good stats...great economy numbers!!! 179.5 miles in 18.2hrs = an average speed of 9.86 mph, well under a typical cruise speed of ~24-26mph.

If you boat in an area where there is little restriction for wake or speed, I would bet you could increase your MPG numbers by spending more time on plane at about 2100-2300rpm and 24-26mph. What do you think?

I guess it all all depends on how you want to spend your time - enjoying the additional hours of cruising time on the boat, or getting to your destination for the least amount of $$$, and spending it on the hook or in your slip.
 
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I ran 700+ miles to NY and back and put $4500 on my credit card. That is an average $6.43 per mile just to come and see youse guys...how 'bout them numbers?

What RPM and speed did you cruise at? I have been told that gassers' sweet spot is where the dyno HP and Torque curves intersect, but don't know this for fact.
 
What RPM and speed did you cruise at? I have been told that gassers' sweet spot is where the dyno HP and Torque curves intersect, but don't know this for fact.

round about 3400 rpm
round about 34 - 36 gph
round about 21 - 23 knots

I have no idea where the curves intersect, but this makes me and the boat happy.
 
Quick stats so far, day #9 of cruising vacation from Bayfield, WI to Isle Royale, MI to Thunder Bay, Ontario. We have traveled 387 statute miles, burning 376 gallons of fuel, in 28hrs.

First 161sm was on plane @ 2300rpm, 28mph - from Bayfield WI to Rock Harbor, Isle Royale MI in a respectable 5.45hrs. Filled with 162 gallons for almost exactly 1mpg at 28gph, 28mph averages. After clearing sailboat traffic at Outer Island, I set the autopilot and did not touch wheel or throttles for 5hrs...fun!

Next leg was largely trawler speeds into a headwind bucking 3-4' chop coming around north side of Isle Royale back all the way back to south end Windigo Ranger Station. We still managed to average 1.1mpg on this fill of 88 gallons at Grand Portage, Minnesota.

Next few days after third tank refill was mixed use around Washington bay near Windigo, back and forth to dockage, shuttling kids to and from Grand Portage. I ran WOT at 32mph for at least 20 miles on this tank to show off to the other boaters making the ~25 mile crossing from Grand Portage to Isle Royale, and I know this fun ruined my chances of posting better overall average numbers.

Yesterday was mostly 2100rpm, 24mph from Grand Portage, MN to Thunder Bay, ON on calm seas. 126 gallons added. We forgot to record split hours/miles at Grand Portage refill, so an overall average at the halfway point of our wander is all I can accurately give of 387 miles / 376 total gallons refilled = 1.03mpg at an average burn rate of 13.4gph and an average speed of 13.8mph.

(NOTE: All generator consumption is removed from these figures by filling port tank first, starboard second, and using 2x port consumption. The generator appears to burn about 1.5gph and we have run it more than usual as we have only had shore power three nights and house (starboard) batteries are 3yrs old and not lasting through the night with a 12yr old refrigerator that runs too much to stay marginally cold. Remember that low batteries and accessories use also contributes to lower MPG as your engines have to work harder to spin those alternators when batteries are charging. Weak batteries DO waste fuel!!!)
 
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First 161sm was on plane @ 3200rpm, 28mph - from ......
.....Third tank was mostly 2100rpm, 24mph........

I'll assume the 3200 is a typ and you meant 2200rpm....if not...something is broke.

Unless you are running with a strong current and a strong tail wind and very lightly loaded......there is NO WAY you are making 28mph/24knots at only 2200 RPMs.

On a typical long cruise like you are taking you will be running very heavy...fuel, water, stuff.

Either your tachs are off or your props are way overloading the motors.

BTW....from 'here' |...................| to 'here' is not 7 inches.... :)
 
(NOTE: All generator consumption is removed from these figures by filling port tank first, starboard second, and using 2x port consumption. The generator appears to burn about 1.5gph and we have run it more than usual as we have only had shore power three nights and house (starboard) batteries are 3yrs old and not lasting through the night with a 12yr old refrigerator that runs too much to stay marginally cold.

Mark, assuming your genny is healthy, that burn estimate is WAY high - even under max load, which is hard to maintain on a 410. (AC's and WH cycle off, and there's just not much for it to power)
 
Mark, assuming your genny is healthy, that burn estimate is WAY high - even under max load, which is hard to maintain on a 410. (AC's and WH cycle off, and there's just not much for it to power)

We have been running it sparingly, as Isle Royale has specific rules about noise. When it is running, there is a very significant load, as batteries are charging, hair dryers are on (wife - i have no hair ;) , water is heating for showers. We use the 'ON' time to the max, then shut it down. My figures are estimates I haven't been recording and calculatiing, but will now to see what the real numbers are.
 
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I'll assume the 3200 is a typ and you meant 2200rpm....if not...something is broke.

Unless you are running with a strong current and a strong tail wind and very lightly loaded......there is NO WAY you are making 28mph/24knots at only 2200 RPMs.

On a typical long cruise like you are taking you will be running very heavy...fuel, water, stuff

Either your tachs are off or your props are way overloading the motors.

BTW....from 'here' |...................| to 'here' is not 7 inches.... :)


Typo corrected...2300rpms, not 3200.

2300rpm full of freshwater, full of fuel, two people and gear = 28mph. 2800rpm makes 32mph. 2100 makes 24mph.

Ever noticed that longer sailboats go faster, on less sail area?

OOOOOOH Dom...just think you could have had a 410!!! ;)
 
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We have been running it sparingly, as Isle Royale has specific rules about noise. When it is running, there is a very significant load, as batteries are charging, hair dryers are on (wife - i have no hair ;) , water is heating for showers. We use the 'ON' time to the max, then shut it down. My figures are estimates I haven't been recording and calculatiing, but will now to see what the real numbers are.

I'm sure it doesn't seem like it when a hair dryer is screaming incessantly, but that's only about half-load!

My gas Westerbeke is rated to burn just over a 1 GPH at full load, but the only way to run 'er for an hour with a full load, is if I'm specifically trying to do so. That would require running hot water, using the stove, both AC's set to an extreme temp, all lights and charger on etc.

Yours, with the load described above, will be a whole lot less.
 
I'm sure it doesn't seem like it when a hair dryer is screaming incessantly, but that's only about half-load!

My gas Westerbeke is rated to burn just over a 1 GPH at full load, but the only way to run 'er for an hour with a full load, is if I'm specifically trying to do so. That would require running hot water, using the stove, both AC's set to an extreme temp, all lights and charger on etc.

Yours, with the load described above, will be a whole lot less.

Agreed. We went back over usage at each dock, dinner, morning, etc. and came up with a GPH burn of about .7gph. Not bad for what utility you get out of each gallon, in the way of hot showers, refrigerated food, hot food, lights, AC, etc....oh and my wife's hair. ;)
 
I could add a fuel meter to the genny's line for $75 and configure it as a "3rd engine" on my MFD. It would be nice to have exact GPH calculations and detect when a tune-up is needed, but I just don't run the genny enough to justify it. Maybe if I find a meter on sale someday...
 
Agreed. We went back over usage at each dock, dinner, morning, etc. and came up with a GPH burn of about .7gph. Not bad for what utility you get out of each gallon, in the way of hot showers, refrigerated food, hot food, lights, AC, etc....oh and my wife's hair. ;)

My gasser gets the same mileage with a full load of everything.
 
Exactly what I found. My 380 was dialed in nicely toward the end of my ownership and it burned 26-27 GPH @ 2400 (24 kts) per Floscans.

Wow. I am pretty sure I could run my 410 at WOT/32mph and never get to those burn rate numbers. What gives???

First 161sm was on plane @ 2300rpm, 28mph - from Bayfield WI to Rock Harbor, Isle Royale MI in a respectable 5.45hrs. Filled with 162 gallons for almost exactly 1mpg at 28gph, 28mph averages. After clearing sailboat traffic at Outer Island, I set the autopilot and did not touch wheel or throttles for 5hrs...fun!

Hmmm...what gives??
 
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Numbers are not adding up. Are you measuring speed with GPS? SOG? 2300 rpm equates to approx 21 knts SOG on GPS depending on wind and current. That is with full water and 3/4 to full tanks. Had props done this year and WOT close to 2825 rpm. Generator does not burn more than 1/2 to 1 gal per hour at worse case.
 

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