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Discussion Starter · #1 ·
Either next Fall or the Fall of 2016 I plan on doing "The Loop." I'm looking for a 25-28 ft. "something" maybe a Macgregor? (any suggestions?) My biggest concern is fuel. Every now and then I will read something where somone says they averaged .25 gallons an hour, but they never say with what.
Anyone have any advise? A 8 horse at 30% power, or maybe a 9.9 @ 25% ? I want to "average" 5 kt.s an hour.

is .25 gallons an hour Realistic? or do you think they left out the part where they sailed in the Gulf and the coast at 0 fuel consumption, while burning a gallon an hour going down the Tom Bigbee?

Thanks for any advise/suggestions.
 

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My Yanmar 1 GM, I believe, sips less than .25 gal/hour at around 2500 rpm.

I have not formally taken measurements, but honestly I would not be surprised if it actually uses less than .25 gal/hour.

It would be a good motor for long distance motoring. Very simple, easy to work on, and just keeps on going seemingly forever. Mine is a 1981.
 

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Captain Obvious
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My 5 hp Merc 4 stroke outboard on my Cat 22 burns about 1 litre per 45 minutes at 3/4 throttle which is about 6 mph. That is something like 20 mpg or pretty close to 1/3 gal per hour.
 

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My 28' S2 sailboat originally came with a Yanmar 1GM with 6.5 hp. In calm water, it could almost get to 5 kts but normal cruising speed was 4.5 kts. It burned less than .25 gal/hr and in fact burned so little diesel as to be a problem because the fuel would grow algae when it sat too long.
I believed I need more power so I replaced it with a Yanmar 2GM with 13 hp and now get a bit over .5 gal/hr, more like .65/hr at a cruising speed of 5 kts and about .75 gal/hr at almost 6 kts. I can reach 6.5 kts in calm water.
Eventually, you realize that time really is money and that economizing on fuel may be less than optimal.
Compare that to my 20' Tolman Skiff with a 90 hp Yamaha outboard that burns 4.5 gals/hr at 20 kts (6 people aboard) and can reach 32 kts with 6 aboard. Assume diesel and gasoline cost the same. To go 20 nautical miles would cost me about 1.1 gals with the Yanmar 1GM at 4.5 kts and would take 4.4 hours. To go the same distance on the Tolman (designed for long distance trips with good fuel economy) would take 1 hour and 4.5 gals.
The reason to take a trip like this is to see interesting things, I say that a powerboat like the Tolman will enable you to see more although the fuel will cost more. Ultimately, you are limited by time, not money.
 

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A small diesel can do that, but not likely an outboard. A four-stroke will do much better than an older two-stroke. A big factor is speed. Power requirements go up with about the cube of the speed (even more as you approach hull speed for the boat). So about 8 times the power at 6 kts versus 3kts.
 

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I am pushing a 27' Catalina with a 9.9 Nissan (4 stroke) outboard. At 1/2 throttle, we move approx. 5 kn in calm water. Fuel usage is somewhere between a 1/4 gallon and 1/2 gallon an hour.

This past weekend (total NO wind both days), we motored a total of 12 hours and used just over 3 gallons of gasoline. Speed averaged somewhere between 3.5 and 5.5 kn.

I love our motor. Electric start. VERY quiet. Absurdly reliable. Alternator charges battery when running. XL shaft. The 4 stroke is nice because NO oil/fuel mixture to mess with. The only downside I've seen so far in 2 years is that it is very heavy. It takes two people to mount it and dismount it every fall/spring, and you need a heavy duty motor bracket.

Overall, we love it. very happy.
 

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I'll ditto Sals statement the 4-5hp outboards might get you into the range of .25 gallon per hour... my 3.5 hp outboard in flat water would run wide open about 45 minutes on 1 liter (size of the tank internal on it)... slightly more for my 6hp, at 3/4 throttle.

My buddies 1GM in his S2 inboard is about .25/hr, but it's a 9hp diesel on a 26 foot boat (not sure a Mac could ever house an inboard, and you aren't hanging the 1GM off the transom).

No question the issue shouldn't be is .25 gal/hr realistic, as you should hopefully plan on having lots more fuel than you could need. I'd put you more at .5 gal/hr to put a safety margin on things, and overcome any possibility of using that by sailing more.
 

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On a trip like that, you will have different conditions on different stretches that will make it difficult to determine in advance your fuel consumption. The Saint Lawrence Seaway, for instance, will have a current going against you much of the time. The Tombigbee will, on the other hand, have no current, whereas the Mississippi will have plenty of current to help you on your way. Rainfall, wind and water conditions will also dictate your fuel consumption. There may be some ares you expected to sail that you cannot and vice versa. It's probably best to have a considerable economic cushion before you tackle something like this, if you want to complete the adventure in one go.
 

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If you want to do the Loop, keep in mind that you will have to sail on Great Lakes and for that you want a boat that can take it. Tartan 27 with a diesel motor would give you shallow draft, fuel economy, and safety and comfort when out in open water. These are not very expensive boats and still quite common.
 

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My Yanmar 1 GM, I believe, sips less than .25 gal/hour at around 2500 rpm.

I have not formally taken measurements, but honestly I would not be surprised if it actually uses less than .25 gal/hour.

It would be a good motor for long distance motoring. Very simple, easy to work on, and just keeps on going seemingly forever. Mine is a 1981.
I agree. I had a Yanmar 1Gm in my 1982 Cape Dory 25D. It used so little fuel it was actually hard to calculate the usage unless you went long distances.

I can remember going from Pascagoula, MS to Pensacola FL on the ICW and motoring a good bit of the way. About half way back, on the return trip, I was afraid I might be getting low on diesel fuel (I had an 11 gallon tank and a non-functioning gauge). I stopped in Orange Beach, FL and filled up. It held less than three gallons. The diesel dock boy looked at me like I was an idiot for stopping to fill up. :)
 

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I'm getting about .33 gal/hr in my 40' Catana, Volvo MD2030 engine(s), and that's an average, including into current and wind, whatever comes. That's about 2300rpm, 6kt into adverse, 7kt or better if with current/wind. Sometimes it's better, I'm sure, if I have helpful external conditions
 

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Discussion Starter · #13 ·
Wow, a lot of good info. I never even considered an in-board. From all the comments it looks like it is time to reconsider some options I thought I didn't have.

I was considering a mid 90's Mac with the swing keel but perhaps there is something a little roomer as well as a bit more stable out there, and just as (if not more-so) economical.

Thanks so much, and keep the comments/suggestions coming.
 

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I would want a well cared for, simple, small diesel inboard (like my Yanmar 1 GM) for a long distance motoring trip that is mainly on protected waters.

You just can't beat the reliability and simplicity and fuel efficiency. I am sure there are some good small gas outboards out there, but too many these days are having a lot of trouble particularly with the ethanol gas. Just go on West Marine or similar websites and read the reviews for small outboards. I would not want to be relying on a gas outboard day after day for 8-10 hours a day for months at a time. That is the type of work that diesel engines are built to do.
 

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I just did a rough estimate and came up with: Coronado 25, 4500# disp. with gear maybe 4900# Yamaha 8, 2 stroke. full throttle against wind and current approx. 5 kts. speed, I figured that will burn about .75 to 1 gph. and thats with a standard prop. I really need a high torque prop.
 

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To give you an idea of how much gasoline an outboard can use. I bought my Cal 25 in Annapolis from someone one the South River one spring day and had to bring it back to the Severn River to Chase Creek. It had 9.9 2 stroke outboard. I had a full 3 gallon tank and a spare 1.5 gallon tank that day. We had to motor almost all of the way because the wind was 15 to 20 knots, right on the nose, it was cold, and we were just trying to get it home.

We ended up sailing it anyway, because about the time we went under the Route 50 bridge, we ran out of gas. :D
 

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Either next Fall or the Fall of 2016 I plan on doing "The Loop." I'm looking for a 25-28 ft. "something" maybe a Macgregor? (any suggestions?) My biggest concern is fuel. Every now and then I will read something where somone says they averaged .25 gallons an hour, but they never say with what.
Anyone have any advise? A 8 horse at 30% power, or maybe a 9.9 @ 25% ? I want to "average" 5 kt.s an hour.

is .25 gallons an hour Realistic? or do you think they left out the part where they sailed in the Gulf and the coast at 0 fuel consumption, while burning a gallon an hour going down the Tom Bigbee?

Thanks for any advise/suggestions.
You'll be able to hit 5 knots/hour but probably not average it in a standard 25-28ft. I figure 4-4.5 knots in the typical conditions I motor (which usually involve head wind/current at crusing RPM's not full out).

As said, if you're worried about fuel you really want a good diesel. With a diesel in that size boat you really will average near 0.25 gallons/hour (unless you actually try to push for 5 knots average).

Note that a prop upgrade can often make a huge difference in motoring performance and many sailboats have poor prop choices. My boat could barely hit 4 knots when I got her and averaged less than 3. Be prepared to upgrade the prop if motoring performance really matters.

Here is a chart for a 1GM10. 2700 RPM's is right about 0.25 gallons/hour.

 

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Also keep in mind the Mac 26 M/X will take a big motor, and you can push them to pretty impressive speeds, they will not get good fuel mileage doing that. They are often talked about for doing the loop as they can go faster and have a lot of room below. If it were me I would look for a stable boat with an inboard diesel. The Gulf, Atlantic and the Great Lakes can get pretty rough. For instance on the ICW the Mac will not allow you to pop out and do a stretch off shore if that is what you wanted to do. Also depends on what you want to do with the boat after you are done. If you want to be able to sail more than coastal afterwards then you might look to get a more sturdy boat. Yes I know some people say you can circumnavigate in a Mac, but not me.

Lots of more capable boats out there for good prices, so I would look to see what you want long term rather than just for one trip.
 
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