How much fuel usage for typical 36' motorboat / cruiser

[Ken Honeycutt]

Was at lunch today when somebody mentioned that I was lucky to have a sailboat considering the price of gasoline. Had been thinking about this the last week since gas prices are approaching $4 a gallon here and now I'm wondering how much a typical motorboat in the mid 30' range with twin engines would get as far as fuel usage cruising at 6 to 7 knots (I'm not thinking about buying one, I just want to gloat whenever I'm out on the water this summer and I see one running at the same speed I'm sailing trying to conserve fuel).

 

[Jerry10776]

I have a friend

with a '42 Carver equipped with gas engines (Cat diesels would have been $75K more). His mpg meter shows about 0.9 - 1.0 mpg while running at slow speed. It goes downhill from there. I would think a boat in the mid 30s would have only a bit better results.

 

[Ross]

If you kept the speed below 75 percent of hull speed

for a 30 foot boat you could probably expect 5-8 MPG. But most of the time that would be barely above an idle.

 

[Maine Sail]

My buddy..

My buddy just bought a 2008 33 foot Grady White center console with twin Yamaha out boards and it will burn about 24 to 26 GPH at cruise. He fishes for blue fin tuna and will be using a LOT of fuel to get there and back!!At $4.75 a gallon for gasoline, at a marina this summer, that's $123.00 for every hour he's at cruise speed... A trip from Little Harbor, NH (where he keeps it) to the Cape would run about $600.00 to $700.00 in fuel..P.S. Another friend has a 90 footer that uses well over 100gph....

 

[Rob19574]

Trawlers

With the price of fuel - I think you are going to see a ton of trawlers in the 30-32 foot range with single diesels gaining in popularity. Sailboats too but you either love them or your a powerboater. I would have a tough time spending $100-200 an hour cruising on a power boat.....I feel that money could be better used on so many better things in life.Rob

 

[Rick D]

Along with Rob's Response...

...an acquaintance had a super clean 32' power with twin Mercury Marine gas inboards. She was a newish boat that he maintained perfectly. He put it on the market 18 months ago after breaking $500 round trip to Catalina from Marina del Rey, about 32 miles each way. He was lucky to sell before the credit crunch and before fuel at the gas docks hit over $5.00 / gallon in MDR (I'm told second hand). I suspect his cost now would be $700-ish. He recently got a Grand Banks trawler. Tell you what, on my last return from Catalina, I was struck by how many larger power boats were motoring at sub-planing speeds. BTW, I was using 1.1 gallons / hour diesel at 70% RPM and just shy of seven knots. FWIW, I paid $4.39 / gallon, discounted. I said in another thread about a month ago that I'd be paying $4.25 for 91 octane for my car this summer. Well, it's only spring, but that's what the local cost is now. RD

 

[TT23844]

Theoretical fuel consumption

According to Skene's 'Elements of Yacht Design' & other sources a gasoline fueled engine consumes 0.62 lbs of fuel per developed HP per hour.A diesel consumes 0.42 lbs per developed HP per hour.Note - that's DEVELOPED HP, not rated HP. Developed HP is the power requirement to overcome all frictional losses, resistance etc external AND internal.That works out to a diesel burning 0.87 US gal / developed HP / hour.For gas it's 1.44 US gal / developed HP / hour.That's the theoretical consumption, but practice should bear this out fairly closely.FYI, gas was taken to weigh 6.187 lbs / US gal ( 3.7853 lit.) Diesel was 7.128 lbs / US gal.

 

[Ken Honeycutt]

*yks You could fly to Europe RT for $700!

Wow! I figure we'll probably take 4 or 5 trips this summer that will average about 50 to 100 miles RT. On one of those twin engine jobs that would be ~ $3,500 to $4,000 with the cost of gas approaching over $5 a gallon. Will probably cost us $100 tops on our boat. Expect to see a lot fewer power boats on the lake this year! I wonder how this will affect some of the projects for instance in the Great Lakes where some marina towns have plans to add or have already added new slips, dock facilities and condos to bring in boaters (I suppose this thread belongs on the sails call lounge so I'll stop) -that kind of cost per mile for a 32 footer is sobering to say the least.

 

[Ross]

TT wrote:

That works out to a diesel burning 0.87 US gal / developed HP / hour.For gas it's 1.44 US gal / developed HP / hour.TT all of your other numbers work out but I think you slipped a decimal point in this calculation..87 gal/hr/ developed hp x 7.128 lbs / gallon = 6.20 lbs/hp/hr.

 

[John Nantz]

About gallon per mile ;D

Or maybe Gallon should be spelled with an "$"? As in, how many Gallon$?My brother-in-law gets about a gallon per mile with his twin-screw but I don't think they've never gone that slow, except maybe a couple times when we were cruising together and then that was only for one leg. The last time they followed us, however, they noticed how 'little' fuel they burned!His argument for the need to 'go fast' was he didn't have all day to get somewhere. Well... now they go 'kinda' fast, say, around 12kts, but not necessarily very far. This reminds me of the tortise and the hare.For family unity I try not to gloat toooo much, but sometimes it's difficult to hold it back. ;D

 

[Benny17441]

I always wonder abou them big sport fishermen boats.

I don't do the math on their fuel consumption but wonder about a ballpark figure of their cost for fish per pound. Taking into consideration the cost of the boat, fuel (they have to go out 100 miles), cost of reels and tackle I would say they may regularly pay upwards of $100 per pound. I go to the supermarket and find nice fish for under $15 a pound and it is already cleaned.

 

[Dalliance]

We'll definately see some changes this year.

I think we've already begun to see the effect of rising fuel costs, the credit crunch, falling home values, and recession on Lake Michigan boaters. This is somewhat anecdotal evidence, but the waiting list for slip assignments in Chicago seems to have gotten a lot shorter this year. I've been sailing on Dalliance for nine years, but just officially become the owner last year, and with any ownership change in the Chicago Harbor system, the new owner starts at the bottom; on a mooring. Or at least that's how it's supposed to work. We spent last season on a mooring in Burnham Harbor (I kind of liked it.)and were told there was a three to five year waiting list for slip assignments. There were hundreds of names in front of mine. Well, you guessed it...I got the slip assignment this year!

 

[Rich (P303)]

I approach coronary

arrest when I fill my little truck up. I definately couldn't handle a 500$ setback at the fuel dock.That's $500 mister... cash or credit!Just think... you could do that EVERY weekend!

 

[letterman]

Thursday the TV station was there

At the marina talking, as the always do - meaning they made a mountain out of a molehill - about the gas prices. Of course, then this became the talk of the marina as everyone is preparing their boats for launch, well, except me and two others who are in the water already. The camera was aimed at the fuel pumps at an angle that would gibe the best picture. Say, who's sailboat was that in the background?Yesterday around the beer cooler (THIS isn't the office - the only water here is what we boat on or flush with) we talked. One couple said they would use the same amount of diesel, about 20 gallons. Robert said he would about the same in diesel. Since I go out more, I'll probably use 50 to 60 gallons of diesel, which should clean out the remainder of my reserve left over from going to a smaller tank. So I will probably have to actually buy some fuel this year (Dammit Man!)Then the power boaters showed up. Most of them run dry at the end of the season, or as close as they can to being empty. Of course many of them never leave the docks all season as they use the boats as their vacation retreats. All in all, the sailboaters will still sail, the gas guzzlers will still stay at the docks, and I will have the lake to myself most of the time.Now, to really concentrate on finding that job. At the rate I am going, it will be September or October before that happens!Enjoy the summer!!Oh yeah, today we burn our socks to the Gods of the season! (look it up - Eastport MD.)

 

[Ken Honeycutt]

James, congrats on getting a slip assignment

I haven't applied for a slip because I kind of like being on a can (I'm in Monroe Harbor) - but I was checking the waiting list for slips for the Chicago Harbors out of curiosity and it seemed strange that some boats got the assignments they wanted right away and others were rejected for the 3rd or 4th time. Just found it kind of odd. I think it has to do with the way they fill out the form.On another note, do you know if they're going to build new docks near Navy Pier? I know they are in the plans if the olympics choose Chicago, but I thought they were also considering building or are building them whether they get the olympics or not.

 

[Dalliance]

Ken, I have mixed feelings about leaving the mooring.

It was much more private and I was able to sail solo on occasion, but the dock is so much more convenient. So it's a trade off.I had noticed the same thing you had about some people being on the waiting list longer than others and I think you are right. If the request is to specific, it can take longer. My request was basically "...give me any slip in Burham but my first choice is to be on the east side of the harbor...". I lucked out, a slip opened up on our old dock on the east side. As for new harbors, my understanding was that three were planned; one near Navy Pier for transient boaters, one at 31st street and one much further south. It seems like the long term demand is there, but if we don't get the Olympics, there will be no urgent need to accomodate over 1,000 temporarily displaced boats, so I don't know when or if they'll get built.I did hear at the yacht yard this afternoon that a new harbor for 900 boats just opened over in Hammond, so that might also explain some of the moving around. It has to be less expensive than Chicago. Back to rising fuel costs - Personally, I'm hoping to hear a lot fewer Cigarrette boats this summer.

 

[Ken Honeycutt]

I'm with you on no more cigarette boats

I hope a few of the gassholes in the big motoryachts are forced to park as well. More than once I've been nearly knocked off my boat by one of these jerks when they throttle up just outside the inner harbor with no respect for the boats around them...I've seen a few of them cut right in front of the Monroe harbor tender as well forcing the operator to take evasive action. Guess thats why I'm going to be gloating knowing they're now paying for their transgressions.I bought my first boat from an individual at Hammond. Good to hear they opened back up but I heard a few say they would never go back due to the way they were treated when they shut the marina down for the casino expansion. Time will probably heal all wounds though.

 

[Gary_H]

I know more than

just a few power boaters who have said they plan on going out a lot less this summer. Many have said they will be mostly sitting at their slips. I believe there may be more sailboats than powerboats out there this summer. If the fuel prices continue to rise through the summer, I think you'll see a lot of power boats for sale come Fall.

 

[Jim]

Diesel, 25 to 35 GPH

Gas, you can doule that.Don't do the crime if you can't do the time, don't do it!

 

[Steve Dion]

Bayliner with twin 140hp diesels

We had a friend with a Bayliner with twin 140hp diesel. His fuel consumption was about 14-16 GPH.We have a fellow with a single 505 Cat in a 42 and it uses 3 - 15 GPH depending on speed.