Looking for large boaters burn rate

[Islandbrah]

I am in the market for a 30 something foot Sportfish or Express w/ tower. Am trying to decide between diesel and gas. That being said if i can work a diesel I will but I am interested in some burn rates from larger fishing boats with twin Gas for power. If I can't get into a diesel I would like to know what not to get in a gasser. Primarily looking for MPG and GPH. Thanks

 

[Fireman431]

Re: Looking for large boaters burn rate

I have a 37' Carver. Runs twin 7.4L (454) MPI gas engines. The burn rates below are for both engines together.

Idle (650 rpm) - 5-6 mph - 3 gph
1000 rpm - 7 mph - 5 gph
1500 rpm - 10 mph - 10 gph
2000 rpm - 13 mph - 14 gph (this is really plowing, too)
3200 rpm - 18 mph - 18-20 gph (slowest rpm on plane)
4000 rpm - 25 mph - 30 gph

You can see that you are looking at an average of 1 mile per gallon. Get used to it. You may do better depending on inherent hull design which dictates hull speed. Also look at power to weight ratios, amount of gear, hull cleanliness, engine tuning, carb vs. injnection, etc. I burn about $1200-1500 worth of fuel a year (which is just over a hundred dollars a month). We use our boat a lot. We just don't haul ***** all of the time. On a bigger boat, the ride there is most of the fun.

In the end, I always say "Get it"!"... you can always sell it later if it's too much, but at least you can say that you did it.

 

[Islandbrah]

Re: Looking for large boaters burn rate

LOL Fireman. I like your philosophy. I am used to 2 to 2.5 MPG on my outboard but I am prepared to buyout BP. I fish about 2x a week but a boat of that size I am sure that will be reduced to weekend overnights. My concern is more range based. If I am going to lay out the cheese for a Convertible I want to be able to hit Key West from my house approx 160 miles from my backyard. The Marquesas or Dry Tortugas would be swell but I know a round about trip would require a stop in the Keys for fuel anyway unless I go diesel I guess. We burn about 400 Gallons a month now, but split 4 to 5 ways it isn't a whole lot more. maybe 30-50 bucks more but we could go overnight therefore the perception of value to time spent on the water goes up. This is my first big boat purchase and want to check all my resources before making the wrong decision. Looks like it is pretty economical in your rig until the secondaries open up

 

[Shife]

Re: Looking for large boaters burn rate

For the use you are describing I would strongly recommend diesel plants. Go with gas for a dock condo. For something that is really going to get used the payoff is there in mileage and operating costs with the diesels. For light use the cost benefits swing to the gas engines.

 

[QC]

Re: Looking for large boaters burn rate

I think I agree with Shife and I rarely agree on these diesel vs. gas comparisons, but here's the way I see it.

You say you burn 400 gal/month now at 2 - 2.5 MPG, let's say with the bigger ride you go down to 1 MPG and you will be at 1000 gallons/month if you choose gas. If that's true, then let's use a 25% savings in MPG with diesel (not true efficiency savings but economic savings, ask me to define if this confuses you). And let's assume both at $4/gallon for this particular exercise. Soooo . . . if all that is true then you would save $1000/month and get your premium back in as many months as you pay in thousands over the gas power. $12K more for diesel = 1 year payback with no calc for increased resale at the tail end which is real and should be considered. But we are not counting the time cost of money either so take as you will.

However if you are really at 2 MPG today the savings go down to $800/month, and if diesel is higher than gasoline (typical, but wavering last couple of years), then the savings go down even more.

These usually don't work out for pleasure boaters, but in your case I think you stand a chance depending on the premium you pay for the diesel engine and diesel fuel.

P.S. I have been in the diesel engine biz for 30 years and usually vote against them from a purely economic standpoint for pleasure boaters. Commercial boats, hands down diesel. This does not take into account any safety benefits and any coolness factor as those aren't really economic issues . . .

 

[180shabah]

Re: Looking for large boaters burn rate

FWIW - no secondaries on firemans 454MPI's
Besides, with a vac secondary carb, there is no sudden fuel "dump" as the secondaries begin to open when the primaries are only at about 60%. Then they ALL continue together to WOT.

Back on topic - I agree that your stated usage definitely favors diesels.

 

[dingbat]

Re: Looking for large boaters burn rate

A friend of mine went from a 32? w/ twin gassers to a 48? Ocean with twin diesels. Brought the Ocean down from his homeport to fish in a tournament this spring. In a 100 round trip he burned $30 more fuel in the 48? diesel than he would have in his 32? gasser. Surprised the heck out of him.

 

[Fireman431]

Re: Looking for large boaters burn rate

Absolutely go diesel for the use you're describing. I went gas for a few reasons.

1) Only two long trips per year. I run the St. Johns River from Lake Monroe in central Florida north to Jacksonville. Go east to the ICW, then south to Daytona Beach for the summer. I make the return trip in Sept or October. (speaking of which...I'm leaving on this trip tomorrow morning!!)

2) Weekend uses only run me about 10 miles from my home port and back. I generally slow cruise out and plane back most of the way. (BTW, I resent the implication that I'm a "dock condo", marina queen, or any other matching nomenclature. )

3) I can perform almost all maintenance on my gas engines. I know crap about diesels. On an aside, replacement of a diesel longblock will set you back triple $$ of a replacement gas engine. Of course, your life expectancy of the diesel is greater than the gas engine.

Before I purchased mine, I did a lot of powerplant investigating, including talking to owners of both types of vessels. Overwhelmingly, they all voted go gas for my uses. I vote go diesel for yours. But, my opinion is worth exactly what you paid for it.

Whatever you do, shop around for the best boat you can afford. The sour taste left behind by a money pit will far outweigh any fun you have on it.

Best of luck with it!!

 

[180shabah]

Re: Looking for large boaters burn rate

(BTW, I resent the implication that I'm a "dock condo", marina queen, or any other matching nomenclature. )

How could you possibly take the dock condo comment as being directed AT you?

Touchy subject at home perhaps???

 

[TOPGUNmich]

Re: Looking for large boaters burn rate

Another huge issue for the diesel boats that guys run up here is the BIODIESEL BLENDS. Biodiesel in the 10-20% does not stink or blow huge clouds of black smoke. Biodiesel above 20% is even cleaner and it runs better in most engines. More lubricosity, cleaner burning equals better for motor. I know alot of salmon captains who use B20 or B50, plus if you get the offroad fuel its .70 cents a gallon cheaper!!!!!!