The C-Brats Forum Index
HomeForumsMy TopicsCalendarEvent SignupsMemberlistOur C-DorysThe Brat MapPhotos

Fuel flow and economy - Marinaut 215
Goto page 1, 2, 3, 4, 5  Next
 
Post new topic   Reply to topic    The C-Brats Forum Index -> All Marinauts, All The Time
View previous topic :: View next topic  
Author Message
Les Lampman
Dealer


Joined: 30 Oct 2003
Posts: 779
City/Region: Whidbey Island
State or Province: WA
PostPosted: Fri Oct 14, 2011 6:57 pm    Post subject: Fuel flow and economy - Marinaut 215 Reply with quote

Hi All,

I have some numbers provided by Rich from the Betty Ann. These numbers were generated with the information given by the engine ECU and the GPS. They were taken over the course of their (almost) 3 week cruise.

The boat was loaded but not to an extreme. Fuel was usually above 1/2, fresh water was usually about 1/2 to full, there was a cooler and a couple of chairs in the cockpit along with mooring items, safety equipment was aboard, and the under galley space fairly full of cookware, food items, and such. Basically, everything needed to spend 3 weeks aboard along with two folks.

2.5 knots ... 1100 rpm ... .32 gph ... 7.8 nmpg ... 9 smpg
5.7 knots ... 1600 rpm ... 1.1 gph ... 5.2 nmpg ... 6 smpg
10.2 knots ... 2600 rpm ... 2.5 gph ... 4.1 nmpg ... 4.7 smpg
13.0 knots ... 3000 rpm ... 3.25 gph ... 4.0 nmpg ... 4.6 smpg
15.2 knots ... 3200 rpm ... 3.50 gph ... 4.3 nmpg ... 5.0 smpg
19.1 knots ... 3500 rpm ... 4.2 gph ... 4.5 nmpg ... 5.2 smpg
21.0 knots ... 3700 rpm ... 4.9 gph ... 4.3 nmph ... 4.9 smpg
23.6 knots ... 4000 rpm ... 5.9 gph ... 4.0 nmpg ... 4.6 smpg
30.0 knots ... 5000 rpm ... 10.0 gph ... 3.0 nmpg ... 3.5 smpg

A lot of folks have asked me for more details so I hope this helps in that effort.

_________________
Les

www.marinautboats.com
Back to top
View user's profile Send private message Send e-mail Visit poster's website
C-Nile



Joined: 09 May 2008
Posts: 638
City/Region: Connecticut
State or Province: CT
C-Dory Year: 2012
Vessel Name: Betty Ann
Photos: C-Nile
PostPosted: Sun Oct 16, 2011 2:27 am    Post subject: Reply with quote

Les, we believe, used gas with 10-percent ethanol as we had when these figures were taken. We have also taken readings after using non-ethanol gas procured at Anacortes' fuel dock, with similar results. It seems that 3500 to 3600 rpms is the sweet spot for our Honda Engine, which gives us approximately 5 statute miles per gallon. This is incredible fuel economy, and we believe it is attributable to a combination of many factors: advanced Honda technology, Ben Toland's efficient hull design, Les' focus on weight reduction going to a hand-laid hull, having no bottom coating, making the hull more slippery, and the clean lines of the camperback that affords better airflow (we think) than a stepped design.

As all C-Brats know, careful planning in the way of using currents and/or winds to one's advantage, and maintaining a steady course, will help to ensure one gets high mileage. What's great about the Marinaut/Honda BF115 combination that one gets optimum mileage at low rpm, but at a relatively high rate of speed: approx. 19 knots! In our opinion, which the Honda engine may be more expensive than its competitors, in the long run, its greater fuel economy will more than off set its price in a very short time, dependent upon how many hours one puts on the engine.

Rich

_________________
Marinaut 215 - "Betty Ann" Sept-2011
CD 16 Cruiser "C-Nile" Sold 06/2011
Back to top
View user's profile Send private message
C-Nile



Joined: 09 May 2008
Posts: 638
City/Region: Connecticut
State or Province: CT
C-Dory Year: 2012
Vessel Name: Betty Ann
Photos: C-Nile
PostPosted: Mon Feb 13, 2012 11:48 am    Post subject: Reply with quote

For those interested -- I posted a graph of fuel flow, mileage, RPM, and speed information, at approximately 3,500 lbs. total weight, achieved in the Betty Ann's maiden voyage in graphical form in my Photo Album "C-Nile"
Back to top
View user's profile Send private message
C-Nile



Joined: 09 May 2008
Posts: 638
City/Region: Connecticut
State or Province: CT
C-Dory Year: 2012
Vessel Name: Betty Ann
Photos: C-Nile
PostPosted: Sun Jun 17, 2012 2:55 pm    Post subject: Reply with quote

Desiring to provide an accurate representation of Marinaut 215/Honda BF115 efficiency, I'm refining my results as follows:

On June 14th, my wife and I took a ride on the Connecticut River near Essex, CT. The water was relatively flat, and about 1 hour after ebb tide had started. With two persons on board, I estimate our total weight at 3,580 pounds. We went for 1/4 mile down river, maintaining 3500 RPM, and using our fuel flow meter I calculated we were getting 5.15 MPG. We immediately turned 180 degrees up river, traveled over the same course, and at 3500 RPM (had to increase throttle slightly) I calculated 5.0 MPG.

Fuel flow meter is one thing, the real world is quite another. After topping off our tanks in May, we took 5 trips, traveling 136 miles. Our weight varied from an estimated 3,580 pounds to 4,000 pounds (we took another couple for a 56 mile trip.) We used a total of 29.8 gallons of fuel and this translated into 4.6 statute miles per gallon (see below). We are delighted with the results.

I’ve been seeking advice from Bob Austin, and he won me over to the fact that the fuel flow meter is a valuable tool to instantly determine the most efficient speed for prevailing conditions in real world settings, but that it is not particularly useful for determining overall trip smpg. Mr. Austin likes our overall approach, because it shows the overall average we “...are getting between fill ups, and often involves some displacement speed, some getting on plane, and of course mostly at what ever your cruising speed is. “ Nevertheless, he characterized the results as “impressive.”

This year has been rough thus far for Long Island Sound, and it seemed that every time we went out, we did not time the tides and winds well, which impacted efficiency. It is comforting to us to know that we are getting good mileage from the standpoint of being aware of the true range of our boat. In my opinion, if a person times their trips to sail with the tide, in periods of low wind and flat water, and maintaining the proper trim and throttle settings, 5 mpg is possible to achieve in this boat, but what's the fun of that? We'll settle for overall 4.6 mpg, punch the throttle to make the boat leap out of the hole and just have fun driving it.

OUR LOG
May 19, 2012..........23 miles, seas "6" -> 1’, boat load 3,580 lbs (est)
May 31, 2012.......... 3 miles, seas < 6”, boat load 3,580 lbs (est)
Jun 7, 2012............ 55 miles, seas 6" -> 1’, boat load 4,000 lbs (est)
June 14-15, 2012... 42 miles, seas 6" -> 2', boat load 3,580 lbs (est)
Jun 15, 2012.......... 13 miles, seas 6" -> 1.5', boat load 3,580 lbs (est)
-------------- ---- --------
Total miles........................... 136 miles
Total gallons fuel consumed....29.8
Average miles per gallon----- 4.6

Thanks,

Rich[/b]
Back to top
View user's profile Send private message
NORO LIM



Joined: 24 Apr 2008
Posts: 875
City/Region: Olympia
State or Province: WA
C-Dory Year: 2006
C-Dory Model: 23 Venture
Vessel Name: NORO LIM (sold 12/12/14)
Photos: NORO LIM
PostPosted: Sun Jun 17, 2012 3:13 pm    Post subject: Reply with quote

Rich,

Do you know what your average speed was for those 136 miles?

_________________
Bill, Formerly on NORO LIM
2001 CD 16, 2001-2006
2006 CC 23, 2006-2014
Back to top
View user's profile Send private message
C-Nile



Joined: 09 May 2008
Posts: 638
City/Region: Connecticut
State or Province: CT
C-Dory Year: 2012
Vessel Name: Betty Ann
Photos: C-Nile
PostPosted: Sun Jun 17, 2012 4:09 pm    Post subject: Reply with quote

Hello Bill,

To come up with an average speed is difficult. Here is a good estimate:

Trip 1. 20 miles at 22 mph, 3 miles at 6 mph, seas 6" -> 1’
Trip 2. 3 miles at 6 mph, seas < 6”
Trip 3. 45 miles at 20 mph, 10 miles at 6 mph, seas 6" -> 1’
Trip 4. 29 miles at 17 mph, 13 miles at 6 mph, seas 1’ -> 18”
Trip 5. 11 miles at 17 mph, 2 miles at 6 mph, seas 1’ -> 18”

We have many, extended, slow-no-wake areas. Also, there was a good chop at times, so to run very smoothly, we like to travel at around 17 mph, which is not optimum for efficiency, but very good nevertheless.

Thanks!

Rich
Back to top
View user's profile Send private message
C-Nile



Joined: 09 May 2008
Posts: 638
City/Region: Connecticut
State or Province: CT
C-Dory Year: 2012
Vessel Name: Betty Ann
Photos: C-Nile
PostPosted: Sat Aug 18, 2012 11:29 am    Post subject: Reply with quote

This year, as of 8/17/2012, the Betty Ann has travelled a total of 778 miles. We have consumed 173 gallons of fuel at an average cost of $4.60 per gallon to total $793 this year. We are averaging 4.5 statute miles per gallon. Actually, our trips range from a low of 4.4 smpg to a high of 4.6 smpg, and the most important determining factor in fuel economy for us (as for most people) has been wind, tides and wave height. If we planned our trips more carefully, and traveled at optimum speeds, we probably could have reached close to 5 smpg much in the same way as Hyper-milers do, but what's the fun in that? When the rubber hits the road so to speak, it comes down to how many miles did one travel and how much fuel did one consume. I use our Raymarine track mileage counter to determine the number of miles traveled. This method is so reliable to me, that when I filled up yesterday, I predicted we would need 42 gallons of fuel, and it took 41.6. This gives our Marinaut a range of 270 miles.

Incidentally, has anyone noticed how much the price of fuel has been increasing lately? In New England, we paid $4.69 per gallon. Imagine what the cost would be, if you will, if we did not have Marinauts or C-Dory's and got only 2 smpg? Instead of $793 in gas, it would have been $1,789!
Back to top
View user's profile Send private message
C-Nile



Joined: 09 May 2008
Posts: 638
City/Region: Connecticut
State or Province: CT
C-Dory Year: 2012
Vessel Name: Betty Ann
Photos: C-Nile
PostPosted: Wed Sep 12, 2012 7:53 pm    Post subject: Reply with quote

Marinaut 215 (Betty Ann) YTD Fuel Update as of 9/12/2012:
....Total miles traveled= 963
....Total gallons consumed= 210
....Total fuel cost= $979
....Average miles per gallon= 4.6

Note: My 9/12/2012 fuel fill was 37.9 gallons after 185 miles traveled, which yielded 4.9 mpg. I tried to exercise more careful planning this time around so as to hit slack tide, or following seas, and I paid more attention to achieving optimum fuel flow. What a difference! I believe I'm right in saying that one could hit 5 mpg if it was a priority, but what's the fun in that? It's like hypermiling in an automobile. I'm very happy with the economy of the combination of Marinaut and Honda BF115, particularly now that in my area, the price of gasoline at the marina is $4.899 per gallon.

Rich
Back to top
View user's profile Send private message
rogerbum



Joined: 21 Nov 2004
Posts: 5922
City/Region: Kenmore
State or Province: WA
C-Dory Year: 2008
C-Dory Model: 255 Tomcat
Vessel Name: Meant to be
Photos: SeaDNA
PostPosted: Wed Sep 12, 2012 9:56 pm    Post subject: Reply with quote

Rich - what's your average speed during that time? The fuel numbers are impressive but don't mean so much without information about speed.
_________________
Roger on Meant to be
Back to top
View user's profile Send private message AIM Address
potter water



Joined: 12 Apr 2011
Posts: 1076
City/Region: Logan
State or Province: UT
C-Dory Year: 1997
C-Dory Model: R-21 Tug
Vessel Name: Poopsy
Photos: Still C-razy
PostPosted: Wed Sep 12, 2012 11:34 pm    Post subject: Reply with quote

As I have looked at these Marinaut numbers and the verious CD 22 numbers that have appeared on this board as well as watching my own numbers and it is interesting to me that the boats, speaking broadly are getting about 2.5 mpg at a "comfortable" cruising speed on plane, and 4 to 5 gph at off plane speeds in the 8 to 10 mph range. It seems to be the case whether one is running two engines or a single larger engine. Yes, hull shape makes some difference, but I think it pretty much takes the same fuel to move 4000 lbs. or so of boat at speed X without a lot of regard to hull shape.

I also think it is really a stretch for anyone to say that their boat gets X miles per gallon as the winds and water and loading and balance and helmsmanship and currents vary dramatically from hour to hour and day to day and load to load.

Smaller displacement engine (s), smaller boats, good helmsmanship and sea knowledge. That is the key to affordable boating in these times of high fuel costs. Lousy helmsmanship will double the fuel consumption of the best hull and engine combination. Good helmsmanship will double the miles per gallon of the worst combination of hull and engine.

Just my feeling a little philosophical tonight.

_________________
You can tell a man his wife is ugly, but never ever criticize his dog, his gun, his truck or his boat.

Never let ignorance interfere with an opportunity to state a knowledgeable opinion

Testosterone Tales-Amazon.com

2006 C-Dory 22 Cruiser 2008-2014
1997 Ranger Tug 21 Classic 2016

KG7RC
Back to top
View user's profile Send private message Send e-mail
rogerbum



Joined: 21 Nov 2004
Posts: 5922
City/Region: Kenmore
State or Province: WA
C-Dory Year: 2008
C-Dory Model: 255 Tomcat
Vessel Name: Meant to be
Photos: SeaDNA
PostPosted: Thu Sep 13, 2012 1:33 am    Post subject: Reply with quote

Harry,

To be honest, I'm not sure how much good or lousy helmsmanship has to do with it. To me it has a lot more to do with how one uses the boat, whether one is in a hurry or not and whether one is most interested in optimizing fuel economy or optimizing a particular kind of fun on the water. Most of my use of both my previous 22 and my current Tomcat has been fishing. When I'm fishing, I'm trying to optimize the fishing fun per unit free time and not fuel mileage. I blast from one potential fishing area to another or run 60 miles offshore for tuna. Once I find my target species, it fish the hell out 'em and then blast back in when I've limited out or run out of daylight. I'm definitely NOT getting the best possible fuel mileage, but I feel I'm getting the best mileage for my $ and free time. I don't consider that lousy helmsmanship, it's just a different goal.

That said, I think your point is that with a little knowledge about the fuel burn characteristics of these boats one can adjust speed to maximize fuel mileage. Without that knowledge, one can easily waste more fuel (especially by running at the "wallowing speed" just before the boat gets on plane).
Back to top
View user's profile Send private message AIM Address
potter water



Joined: 12 Apr 2011
Posts: 1076
City/Region: Logan
State or Province: UT
C-Dory Year: 1997
C-Dory Model: R-21 Tug
Vessel Name: Poopsy
Photos: Still C-razy
PostPosted: Thu Sep 13, 2012 9:17 am    Post subject: Reply with quote

We are in agreement. When I use the term helmanship, I'm really talking about the person who makes all of those decisions about making the mission...fishing, cruising, whatever...the most successful balance of time, speed, water conditions.
Back to top
View user's profile Send private message Send e-mail
Will-C



Joined: 21 Aug 2007
Posts: 2476
City/Region: Temple
State or Province: PA
C-Dory Year: 2008
C-Dory Model: 23 Venture
Vessel Name: Will-C
Photos: Will-C
PostPosted: Thu Sep 13, 2012 10:30 am    Post subject: Fuel flow and economy - Marinaut 215 Reply with quote

I just wanted to mention a note about bad helmsmanship. I think it can have a poor effect on fuel mileage. Speeding up and slowing down for no apparent reason, unnessary sharp turns, an improperly loaded boat, motor trim and trim tab settings not in tune with current conditions. Similar to people in hybrid battery equipped cars riding in the passing lanes on an interstate highways doing less than the posted speed limit Love unable to maintain a steady speed of any kind etc.
D.D.

_________________
Chevrolet The Heart Beat Of America
Back to top
View user's profile Send private message Send e-mail
thataway



Joined: 02 Nov 2003
Posts: 20778
City/Region: Pensacola
State or Province: FL
C-Dory Year: 2007
C-Dory Model: 25 Cruiser
Vessel Name: thataway
Photos: Thataway
PostPosted: Thu Sep 13, 2012 4:24 pm    Post subject: Reply with quote

Hull design has a lot to do with it. A flat bottomed boat, will do far better than a 26 degree deadrise deep V. (maybe half the mileage in the Deep V).

My father always chided me when I was young--that I was a chinese sailor, trying to break the dragon's back which was following the boat....I learned to steer a straight course--and that is the way you win sailboat races. Almost equal to more miles per gallon....

Helmsmanship also involves anticipating wind shifts and current shifts, wakes etc...

5 miles a gallon seems a stretch--but 2.5 miles a gallon is a bit low for a 4 stroke on a 22--again--the weight does come into effect on identical boats, as well as bottom paint, trim, prop, etc.

_________________
Bob Austin
Thataway
Thataway (Ex Seaweed) 2007 25 C Dory May 2018 to Oct. 2021
Thisaway 2006 22' CDory November 2011 to May 2018
Caracal 18 140 Suzuki 2007 to present
Thataway TomCat 255 150 Suzukis June 2006 thru August 2011
C Pelican; 1992, 22 Cruiser, 2002 thru 2006
Frequent Sea; 2003 C D 25, 2007 thru 2009
KA6PKB
Home port: Pensacola FL
Back to top
View user's profile Send private message Send e-mail
Will-C



Joined: 21 Aug 2007
Posts: 2476
City/Region: Temple
State or Province: PA
C-Dory Year: 2008
C-Dory Model: 23 Venture
Vessel Name: Will-C
Photos: Will-C
PostPosted: Thu Sep 13, 2012 4:52 pm    Post subject: Fuel flow and economy - Marinaut 215 Reply with quote

We have a 23' Venture with a Yamaha 4 stroke 150 and we average around 3 mpg. I rarely have the motor above 4500 rpm. Normally we run between 3500 and 4200 rpm. We usually have a 55 pound dinghy with us and a 2.5 hp Yamaha dink motor and a 65 quart cooler, along with tools, clothes, barbecue, full water tank, roof top air and a Honda EU 2000 generator with five gallons of extra gas for the generator. I don't know if we would be considered loaded heavy but we can't be considered light. I don't factor in if I'm running with the tides or tailwinds. We spin a stainless 3 blade prop 14 1/4 x 17 and use a Permatrim. We start out with 60 gallons of fuel. I would guess a 22 would have to get at least 4 mpg. But we only have a 14 pound anchor. Very Happy
D.D.
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    The C-Brats Forum Index -> All Marinauts, All The Time All times are GMT - 5 Hours
Goto page 1, 2, 3, 4, 5  Next
Page 1 of 5

 
     Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum



Page generation time: 0.1788s (PHP: 65% - SQL: 35%) - SQL queries: 33 - GZIP disabled - Debug on