Economic Fuel Consumption

[2BonC]

Having read many inputs about performance there is less about fuel economy. Here in Germany the fuelprises have risen dramatically. E.G. at the present the price for one liter of unleaded normal fuel is about 1,60 € (Euro). As 1 € equals about 1.60$ this is about 2,56 $ per liter. One US gallon is 3.78 liter that means that we have to pay here 9,68 $ per gallon. By the way what is the everage price in the USA right now?
Looking at this prices You might emagine that I pay attention to my fuel consumption more than to speed.
The first thing I do, I try to sail where and whenever it is possible, even going with 2kts and less.
If I have to motor with my Suzuki DF50 from 2005 I usually go with about 2400 RPM at 6kts (not SM) with the ballast tank filled, rudders parcially down,fins fully down, mast raised, sailes attached but stowed in covers. At this configuration my fuelconsumtion is about 3liters (0,79US gallons) per hower. I have a 3blade prop as delivered with the engine, 11 6/8 x 14 is engraved on it.
Does this sounds reasonable to You, how about Your experience as far as the fuel economy is concerned?

My boat (MG26X) seems to be quite slow, in the configuration above but with ballast tank emty and everything up it goes about 12kts and gets only 4800RPM.
I now bought a 4blade 14inch prop from VolvoPenta. I think it is very similar to the piranha prop which was mentioned in the forum before. I´m going to try it out next week when I´m traveling to the Lake Geneva in Swizzerland. Some hints for the use of the 4blade prop as far as pitch is concerned?

The throttle of my engine is moving very strong, specially in the endrange. I had it to a Suzuki mechanic because I thought the lever was limited by something but everything seemed to be ok.

I really understand all the guys who like to go fast, from timt to time it´s fun for me too to overtake other sailors with their ordenary sailing boats and beeing first in the marina.
When I went out boating once with my grandson (5years) using my MG19 by that time which was really fast under engine (had a beautyfull white 50 PS Johnson 4Stroke engine) but was sailing like an injured duck he said: Boats with two engines I love, boats with a single engine are quite good but sailing is a sh~t!

Older folks sometimes have a different view on the things!

2BonC

[jaguar496]

Hello 2bonC: just had a fairly lengthy motor trip, not in distance, but in time. We have an '08 with a df40 suzuki. this morning found us with no wind at all we motored at 2200rpm for 4hrs. gps averaged 4.8kts. we had the daggerboard down approx .33mt, and one rudder all the way down. I figured that we consumed approx. 2 gals, and will fill the container tomorrow in order to find the acutual amount. no wind, mainsail cover off, jenny furled, bottom paint, ballast filled. hope this helps. Alice and Stew, "THE RESTLESS TWO"

[2BonC]

Hello You restless,

I think the figurs match as far as RPM and speed is concerned. Did I understand it right, You go with one rudder up and the other down? I never considdered this!

Rainer

[Frank C]

Rainer,

Welcome Aboard, & congratulations on the new boat! I'm thinking your boat is a '97 Mac 26X, from reading other posts? You can add that info to your profile, just after your "Location." (See my boat & motor info at left side [er, correction: RIGHT side] of this post.)

Gasoline in the USA varies from $4 to $5 per gallon right now. It is always more expensive to purchase at Marine stations, and cheaper to buy from automotive stations. Obvious then, I try to refill my tanks when towing to a launch ramp.

Yes, it's common to use only one rudder when motoring, to reduce drag. I also like to drop just 2 inches (maybe 5 cm) of Centerboard line. That drops a small section of centerboard below the hull (about a one-foot triangle), to help with straight tracking, directional control.

[c130king]

(See my boat & motor info at left side of this post.)

Frank,

You are obviously "Old School"...on the new & improved website the boat/motor info is on the starboard side of the post.



Jim


ModsAdmission: Oops! Profile is now "to right" ... my bad~!! ~fc

[2BonC]

Hi Frank,
I will amend my boat & motor info very soon, my boat is a 26x from 2003 with a Suzuki DF50 from 2005. I owned this boat three years ago. Befor that I had a MG19. I could post some mods for the 19 too, e.g. I installed a wheelsteering system for motoring, however only e few people might be interested. I have to hold boats like the Mc Gregors because I´m living in the south of Germany, 100 miles away from a lake.

In Germany we have very similar boats to the MG26x/M. They are of much higher quality, more spacy and can be equipped with engines up to 120hp but they are more expensive too.I could post pictures of them....if I could
I have visited the MG-pages for years and have stolen some initial ideas from them for my mods but I registered not until June this year.

Rainer

[Hamin' X]

I could post pictures of them....if I could

Rainer,
You should be allowed to post images at this time. Have you read the
http://macgregorsailors.com/forum/faq.php page yet? It is quite easy to post pics here, but you must first upload them to a public website such as http://photobucket.com/ , or http://flickr.com/ ,etc. Once you have your pics online, you just click on the Img button at the top of the editing box. Then place the link to your pic in between the ][ brackets. It will look like this:

Code: Select all

[img]Link to your photo[/img]

Good luck

~Rich

[bubba]

We own an 07 with a 70 hp Suz and my best fuel consumption is when I keep it below 2000 RPM this gives me about 1 US gal an hour usage with full ballast in rough water at a speed of about 4.5 MPH according to how rough the water is. We are usually loaded with gear for gunkholeing for a couple weeks or more and pulling an inflatiable 10 ft dingy.

[bastonjock]

Hi Rainer

I can sympithise with you regarding fuel prices,in the UK we are paying 1.20 GB pounds per liter.I tend to keep the revs down to 2000 rpm,when i use the engine on its own,i dump the ballast,use one rudder and a little bit of center board

[J.Teixeira]

Did anyone tried these in a Mac??

More control ?

Better planing ?

fuel economy ?



http://plastimo.com/catalogue/1/8190002.html

Jose Texeira

[2BonC]

Hi,
I don´t know the foils You showed however I have done comparison tests with standard airfoiles I bought from Westmarine. By this time I used a with a 50hp Johnson engine (the same as Suzuki DF50). I found out that the boat was allways at least one knot slower with the foils than without . I now have the 26x but I would never use foils again. One question, why do You think Suzuki ore Envinerude don´t sell their own foils or equip their engines with them right away ?

[Kelly Hanson East]

The manual specifically recommends against the use of foils - dont recall the manual but pretty sure it does the same

[bubba]

Your right no foils in the manual and the web site too.

[c130king]

Is the Powerthruster considered a foil?

I know that several of us have one. Can't really prove that it improves efficiency or fuel consumption but I feel like it does.

Jim

[Robert]

I used a Piranha Propellers foil on my Suzuki DF50. It helped keep the bow down when motoring at high speed. It also made the boat lean when turning at speed. I think the foils are tools that can be used with good results when operated by someone that understands them. The motor angle (trim) with power raise/lower engine mounts can be optimized for best economy, the foils give the trim adjustment more effect.
..
That said, I think there is no doubt that the foils add wet surface area and no thrust so they do not help economy particularly at slow speeds. Power boats that go much faster than the Mac26X may get economy from a more level running boat, in that case I think they are making up for poor hull design.

This discussion thread is all about economic fuel consumption and so we are talking about slow speeds where the foil will not even add lift, but still adds drag.

2BonC, I like your posts. I don't have a Mac26X at the moment and the issue of fuel economy is on my mind as I decide what boat and motor to eventually buy. We had the 1999 26X four seasons or so. The first season the whole family used it almost every second week, the next years use dropped by 2/3 per year until I was just making time to keep it clean and run it an hour or two alone at the lake to keep the motor in good shape once every other month. So, when the Mac26M was introduced, and people wanted more Mac26X boats which were no longer available new, I was offered a very good price and accepted.