Fuel consumption: sail/motor. are you serious?!

[Sailing Hanse37]

Originally Posted by sailorboy1

It is hardy anything. In 7 years of cruising full time the direct costs on maintaining my engine are only around $100/yr and I avg 360 hr/yr of motoring time. So even if a trawler is 5x that is $500 and nothing in the big picture

Fully correct: a full service kit, including all filters, impeller and some joints cost about 50$, a V-belt is about 20 and 5 litres of engine oil about 30. As we do all maintenance ourselves, this adds up to about 100$ per year. Every 5years we replace the volvo seal, which costs about 250$. This is for a 54 hp Yanmar on a 43 ft sailboat. We live full-time aboard.

[boat driver]

Originally Posted by Anton Tokar

Hey all!
I just for a minute considered getting a motorboat instead of a sailboat as my first boat (for liveaboard).
and I asked to chat with GPT to give me a fuel consumption comparison.
And I cannot believe my eyes,
how could a boat eat 30-100 liters an hour???
just impossible.
what would be my budget for motoring 24 somewhere???

liveaboard-
one can not utilize a single power component like diesel and ask for an answer even remotely close to accurate. Not enough info to begin with.
To answer your immediate question- power vs sail-
when looking at a boat- the question should be gallons (liters) per mile used.
IE, cruising speed and/or your desired speed.
So @8 knot 60' trawler burns 6 gph. therefore .6gpm so if moving 48 miles in six hours about 36 gallons. But if time is critical, the same vessel burns 2gpmile @ 40kts, so can be there in a bit over one hour at 90gallonds of fuel.
Now lets take a 40 foot sailboat. top speed is 6 knots and burns .1 gpm when motoring, this is obviously more efficient. But if one adds 15K worth of petroleum derived sails onto the rig, one begins to see the complexity of the formula and thereby realistically, I suspect sailboats are not cheaper because the wind is free.....

[Nicholson58]

Found it! Beene original passagemaker. Nice pictures, nice very hard working folks. Great story.

https://www.passagemaker.com/technic...agemaker-refit

[eric12]

I run our Detroit at 800 rpm, I get 10.9 kts
That is 8.5 kts.
Ensenada Mexico to Mazatlan Mexico is about 1000 miles. Cost us almost 8k in fuel.
We use our fuel gauges as fans for the bridge.
Eric

[Flagfish]

Originally Posted by pcmm

like all boats, what you burn depends on the type of boat, the engines, the driver, etc. one of my friend just brought a new to them 40ft twind diesel Searay home and to get from Long Island Sound to Troy, NY they burned 185 gallons of Diesel...That's more Diesel than I used to go from Whitby Ontario to Sandy hook, NJ AND BACK!!!

I used a sum total of 3.5 gallons to sail from British Columbia to San Francisco, then Hawaii and back in my 27' Albin Vega. Around 7,000 n.m.

[RedneckRedcoat]

Originally Posted by boat driver

liveaboard-
one can not utilize a single power component like diesel and ask for an answer even remotely close to accurate. Not enough info to begin with.
To answer your immediate question- power vs sail-
when looking at a boat- the question should be gallons (liters) per mile used.
IE, cruising speed and/or your desired speed.
So @8 knot 60' trawler burns 6 gph. therefore .6gpm so if moving 48 miles in six hours about 36 gallons. But if time is critical, the same vessel burns 2gpmile @ 40kts, so can be there in a bit over one hour at 90gallonds of fuel.
Now lets take a 40 foot sailboat. top speed is 6 knots and burns .1 gpm when motoring, this is obviously more efficient. But if one adds 15K worth of petroleum derived sails onto the rig, one begins to see the complexity of the formula and thereby realistically, I suspect sailboats are not cheaper because the wind is free.....

Not even the engine manufactures go off gallons per mile. It’s gallons per hour at engine revs. You could be doing 3500 revs and go 1 mile in 4hrs or do 1500 rev and travel 5 miles in 1 hour, one would use far less diesel than the other.

We are not replacing sails or lines every year but on average they last about 10 years. Even at $20k that’s only $2000 over 10 years. We have traveled 1000 miles since December. If I sail 1000 miles in a year that’s $2 a mile almost half the cost and will be even cheaper if I clock up more miles were as in a the example above the Trawler the cost per mile is going to go up by $3.75 for every mile traveled

Sailing is way cheaper and economically

[Sailing Hanse37]

Originally Posted by boat driver

liveaboard-
one can not utilize a single power component like diesel and ask for an answer even remotely close to accurate. Not enough info to begin with.
To answer your immediate question- power vs sail-
when looking at a boat- the question should be gallons (liters) per mile used.
IE, cruising speed and/or your desired speed.
So @8 knot 60' trawler burns 6 gph. therefore .6gpm so if moving 48 miles in six hours about 36 gallons. But if time is critical, the same vessel burns 2gpmile @ 40kts, so can be there in a bit over one hour at 90gallonds of fuel.
Now lets take a 40 foot sailboat. top speed is 6 knots and burns .1 gpm when motoring, this is obviously more efficient. But if one adds 15K worth of petroleum derived sails onto the rig, one begins to see the complexity of the formula and thereby realistically, I suspect sailboats are not cheaper because the wind is free.....

Your figures are way off. Sails cost half of what you are saying, we burn about 1/10 th of your estimated fuel consumption for a sail boat. Nothing holds together, except maybe speed. But we are full time living aboard and do not need speed, quite on the contrary… with a motor boat, even the most efficient one, we would not have the budget to cross oceans and living our life like we do

[Pete7]

Originally Posted by MicHughV

Add to this, marina fuel, which is typically the non-blended variety, and also comes at a premium.....around $6/gal.

A short fishing trip can set me back $300 in fuel costs......it takes $900 to fill the fuel tank...

I think I'll go cry in my beer...

One of the reasons we prefer the yacht is we don't trust Governments. Without getting all political on CF, Lots of European and the UK Government have stated that no new petrol and diesel cars after 2030 > 2035.

So how to persuade lots of ordinary people to switch to electric? UK fuel tax is currently about 57% of the retail price. Collected by the retailers and given to the government which can and does increase and reduce the tax rate without needing and changes to law. A slow steady tweak of the fuel tax which only stopped due to Covid is a very simple and cheap option for Governments and they don't even have to do anything to collect it.

I think boats will just be swept up along with cars etc and there really isn't a reason to complain. Newspaper headlines along the lines of "rich yachties given tax free fuel to power there luxury yachts" isn't going to go down well with the populace. Would I want a Miami Vice powerboat today? no thanks.

Pete

[RedneckRedcoat]

Originally Posted by Pete7

One of the reasons we prefer the yacht is we don't trust Governments. Without getting all political on CF, Lots of European and the UK Government have stated that no new petrol and diesel cars after 2030 > 2035.

So how to persuade lots of ordinary people to switch to electric? UK fuel tax is currently about 57% of the retail price. Collected by the retailers and given to the government which can and does increase and reduce the tax rate without needing and changes to law. A slow steady tweak of the fuel tax which only stopped due to Covid is a very simple and cheap option for Governments and they don't even have to do anything to collect it.

I think boats will just be swept up along with cars etc and there really isn't a reason to complain. Newspaper headlines along the lines of "rich yachties given tax free fuel to power there luxury yachts" isn't going to go down well with the populace. Would I want a Miami Vice powerboat today? no thanks.

Pete

Could you imagine a Tesla Battery in a boat talk about ballast !

I think they will have a harder time with boats as a lot are powered with outboards you couldn’t fit enough solar and batteries in a Boston whaler to get the same horsepower.

Plus the rest of the world is not going to follow along and by the time they do we will be fish food and long gone.

A typical fishing boat would need a way of recapturing the power it’s using and it’s just not economical or even possible at the moment

[RedneckRedcoat]

Interestingly Rand boats offer an electric hybrid version of their 20 foot power boat. The battery lasts 20 hours at an average of 4 knots and a max speed of 10 knots. Then you would need to recharge it some how

[Adelie]

Originally Posted by RedneckRedcoat

Or you could not use any fuel and just sail everywhere when the conditions are right.



Having spoke with yanmar support recently you shouldn’t really measure gallons to nautical miles or speed, it should be to rev’s . We have a 40 foot sailboat. At 1500 revs we use 1/2 gallon of diesel an hour when motoring. At 3000 revs slight over a gallon an hour.



knots is going to depend on how clean your bottom is , are you going into a head wind or is the wind behind you, are you going with a current or against a current.



All of that can effect the speed you’re actually doing as compared to the Revs your engine is producing.



We motored for hours on one occasion up cape fear to Wilmington from snows cut doing 3250 revs and only produced 1.5 knots due to current and a 30 knot head wind.

As a die-hard sailor I would forego the motor until the crew squawked. Tall mast and good light air sails would make me happy as a clam.

Engine producers provide gal/hr burn rates because that’s the data they can provide. MPG is going to depend on boat length, speed, displacement, extra loading, bottom condition and hull type. They don’t know what boat you are using their engine in and it’s too much work to figure out for all the myriad possible cases. So of course the only thing they want to talk about is gal/hr. That doesn’t mean it should be the value everybody uses.

But as a boat user I don’t care about gal/hr unless it can be used to tell me 2 other things:
A. Can I get to where I want to go with the fuel I’ve got?
B. How much is it going to cost?
C. Knowing how long it’s going to take would be nice but that’s secondary to the first 2.

Mpg and gal/hr both depend on speed thru the water and opposing wind&seastate.

When I go somewhere what’s the thing I can measure from a map? Distance, usually in nm. If I know mpg I can go straight from distance to gallons needed. Nm/mpg=gal

If I know gal/hr and the speed it produces for the existing conditions.

Dist/speed=hours
Hours*gal/hr=gallons.

More steps and more opportunity to make math mistakes.

What I would do is set up a table with engine revs (generally easy info to get) on one side and opposing wind on the other axis.

The data in each matrix square would be mpg & speed and you could toss in G/hr too.

You would have to test your boat in varying conditions and engine revs but it would be a good planning tool for your specific boat for years to come.

If I needed to go up wind against 30kt I would sail or motor-sail which would be a lot more comfortable and less wearing on the crew and I believe safer.

[Adelie]

Originally Posted by Nicholson58

Found it! Beene original passagemaker. Nice pictures, nice very hard working folks. Great story.



https://www.passagemaker.com/technic...agemaker-refit

Beebe, I believe.

[Adelie]

Originally Posted by RedneckRedcoat

…

I think they will have a harder time with boats as a lot are powered with outboards you couldn’t fit enough solar and batteries in a Boston whaler to get the same horsepower.



Plus the rest of the world is not going to follow along and by the time they do we will be fish food and long gone.



A typical fishing boat would need a way of recapturing the power it’s using and it’s just not economical or even possible at the moment

You could have all the power you want using batteries and an electric motor in a Whaler, you
Just can’t have the range the liquid fuel provides.

If the typical fishing boat slowed way down it would have the same range on EP as ICE. That doesn’t work for most people that have a schedule to keep but that a time constraint not an economical one.

[Be Free]

Originally Posted by RedneckRedcoat

A wise old sailor once told me to do this as well.

It also helps with stabilization of the boat and helps stop interference from waves.

Plus the added benefit is that powerboaters tend to give way because they assume your undersail

But surely you are displaying your motoring cone or steaming light!!

[mvweebles]

Originally Posted by Sailing Hanse37

Sails last over 10 years. Our first set of sails, which were not so good quality, lasted 12 years. Replacement costed us about 8k$. Replacement cost of the sails is much much lower than the fuel we would have used. And more important: thanks to thes sails we were able to do ocean crossings which would have been absolutely impossible without the sails.

Steve Dashew is on record as saying he gets about 3500 hours on a sail, though likely he tosses it before an average cruiser who will tolerate baggy performance.