Fuel Burn on Our Mainship

[Cartouche]

I am looking for confirmation on my Fuel burn numbers it seems awfull cheap to run for me but Math is Math Cartouche is a Mainship 390 up in Canada so we only use her 5 Months a year she has a single Yanmar 370Hp with a Koehler 8KW Generator which we have only put 4 hours on since purchase in 2017, Comments would be appreciated as we are planning an extended cruise this year and want to make sure my math is close.
All info is from our Log
2018
Engine Hours at Launch 1705.26
Engine Hours at Haulout1783.11
Engine Hours Used 77.85
Fuel full at Launch
Fuel Purchased $1,557.59 (Average price of $1.70 CDN per Litre
Distance Travelled 509.38 NM
My Calculation is
$3.06 per NM
0.09 Hrs per Litre
0.56 NM to the Litre
average speed was 6.95 Knots
Average RPM was 2070:37
2019 (We did a lot more Locks and River cruising)
Engine Hours at Launch 1783.11
Engine Hours at Haulout 1863.99
Engine Hours used 80.88
Fuel Full at Launch
Fuel Purchased $1,371.80 (Average price of $2.00 CDN Per Litre
My Calculation is
$3.00 per NM
0.12 Hrs per Litre
0.67 NM to the Litre
average speed was 6.03 Knots
Average RPM was 1975:00
Many thanks in advance [/FONT]

 

[LaBomba]

I calculate that to be around 2 gallons per hour and that to me is not unreasonable considering your speed. At the end of the day it is what it is and you have to plan fuel stops accordingly.

 

[Cartouche]

Many thanks it seemed low to me but the numbers don't Lie cheers

 

[Jeff F]

They look right to me. Averages and hours can get a little skewed when locking, but the NM/l should be consistent and easy to use for planning, particularly if you operate within a narrow speed range.

I think we went through some locks together last spring heading north from Kingston last spring. Your boat looks nice!

Jeff

 

[Pete Meisinger]

The only thing that jumps out at me is $1.70 per liter, thats around $7.00 a gallon. Come to the U.S. and enjoy cheaper fuel.

pete

 

[Baker]

My advice to you is use your boat more??. But seriously, you are killing your generator by not running it. Fire that thing up and load it up every now and then. There’s probably a chance that something is wrong with it already and you don’t know it….sounds like a boat?. Cheers. And don’t sweat the cost of fuel. Just enjoy life!

 

[MacPhid]

Price per litre seems high for those years, in 2018 in Georgian Bay I paid $1.48 per litre and in 2019 it was $1.42 per litre on the Trent and $1.37 per litre on Georgian Bay.
For comparison we average 1 litre per kilometre which would be about 0.5 nm per litre averaging around 7 knots.
.67 nm per litre at 6 knots seems about right for a Mainship 390. Your current Sundancer probably doesn’t do as well[emoji15]

 

[Bacchus]

From a 2019 extended cruise. (I work in gal & miles as mostly canal & inland / great lakes cruising and guides & charts are in miles)
Over 2-1/2 months and 1,000 mi I burned about 425 gal including about 40 hrs of gen time.
I avg 75% slow cruise about 8 mph and 25% fast cruise about 13-14 mph
I dont bother tracking $ as it's meaningless w price variation and has no relationship to engine performance... I do look for any oddities or abrupt changes in efficiency to indicate a pending problem.

 

[Pete Meisinger]

OK, I know a 39 foot Mainship is not a 36 foot Albin. But here are some bonified facts about my Albin

Average burn: 1.5 gallons per hour (about six liters)
MPG: About 6 (unheard of in the boating world but FACT)

pete