How much GAS would I use on in a day on the lake

[northernmerc]

Re: How much GAS would I use on in a day on the lake

As a GENERAL rule of thumb, take your horsepower, divide it by 10. That is the max gallons per hour you will burn at full throttle. Just cruising isn't bad, you might be half that or less, wakeboarding can suck some gas though.

That formula is wildly inaccurate for the 4.3 Mercruiser.

 

[QC]

Re: How much GAS would I use on in a day on the lake

Not wildly ^^^^ take a look at some test data. It is still a decent (conservative) rule of thumb for wide open. Also, not a big difference between OBs and I/Os with modern technology, in fact some OBs get better efficiency as they weigh less, even two cycles. True inboards are the worst

There is no way you will use two tanks unless you take one tuber off and replace with another from dawn to dusk. Yes 20+ gallons an hour is possible, but you'd have to run wide open for that same hour.

I have used 60 gallons in a day once and I ran over 150 miles, plus screwed around. 23 footer with a 320. 30 - 40 MPH cruise. Loooooong day. I run the snot out of my boat and rarely use over 30 gallons. Whenever you are picking up tubers, idling, cruising, even pulling the tube you are NOT using max horsepower, so you are not burning at the max rate. Oh, and they don't use any when they're off, like at anchor, lunch, swimming, talking. And you will do all of that. I'll bet you will usually get two days out of 30 gallons although this is NOT a range discussion and don't EVER bet on better than 3 MPG for that . . .

 

[H20Rat]

Re: How much GAS would I use on in a day on the lake

That formula is wildly inaccurate for the 4.3 Mercruiser.

sure 'bout that? Just looked up the specs for a random boat on boattest.com with a 190 hp 4.3 merc EFI. 2006 Tahoe 215 with a 4.3 merc at 190 hp. 16.1 GPH at 4800 rpm/48.5 mph.

Yes, 16.1 GPH is less than the estimate of 19, but it gets you very, very close. That is also for a new boat. Throw in 10 years of use and old slightly out of tune carbs, and you could easily see 19.

Keep in mind that is WOT. Not many people will hold a boat at WOT for an hour to test that out, so it doesn't ever seem that bad. (and very few people have a flowscan or similar to see real time fuel consumption. Personally I would NEVER have one on board, I don't WANT to know!)

I do have to admit, that rule is a little on the high side for a modern EFI engine. The 220 MPI 4.3 in particular matches the 190 4.3, and in most cases is better.

 

[Lrider]

Re: How much GAS would I use on in a day on the lake

And I here I was thinking I could go to Mexico and back on my 65 gallons

Dang

 

[QC]

Re: How much GAS would I use on in a day on the lake

1/3 out, 1/3 in, 1/3 reserve . . .

 

[mattb1974]

Re: How much GAS would I use on in a day on the lake

And I here I was thinking I could go to Mexico and back on my 65 gallons

Dang

hopefully you are smuggling illegals BACK to mexico with that trip

 

[Lrider]

Re: How much GAS would I use on in a day on the lake

nah jus a little girl named Mary Jane

 

[GatorMike]

Re: How much GAS would I use on in a day on the lake

Believe it or not how rough the water is has a huge effect on my boat. I have a 55 gallon tank and 2 years ago we went from Ft Lauderdale to Bimini over flat seas. I filled up in Bimini and it took 25 gallons. I never took the boat out while we were there (fished from a friends boat) and on the return trip over very rough seas I ran out of fuel a mile short of Ft Lauderdale. Thank God my buddy boat had a 5 gallon can on board.

 

[kenmyfam]

Re: How much GAS would I use on in a day on the lake

I am buying a 19' Bayliner Capri with a Volvo Penta I/O engine and I am just curious on what I would expect a full day on the lake of cruising and wakeboarding would use in gallons of gas. REAL ROUGH guesses are fine, Just trying to get an idea if I fill up the 30 gallon tank in the morning if I would have a full day of fun without too much worry. I know it sounds stupid but I know nothing about boats and just trying to get a decent baseline of info before I go out.

You have to define just what a "full day" means to you. How much down time you have at anchor or beached while taking a break will sure cut down on the fuel usage !!

 

[smokeonthewater]

Re: How much GAS would I use on in a day on the lake

it could be worse..... if you were in my boat and using full throttle then you would empty the 100 gallon tank in 2 hours.

I expect to spend ALOT of time at anchor

 

[SoTexGuero]

Re: How much GAS would I use on in a day on the lake

I have never gone through a tank in one day (30+ gallons)....I'm easy on the throttle, pulling my kids on boards or the infamous tube and really only cruising around 25-35 mph (wife is always aboard).

 

[25thmustang]

Re: How much GAS would I use on in a day on the lake

it could be worse..... if you were in my boat and using full throttle then you would empty the 100 gallon tank in 2 hours.

I expect to spend ALOT of time at anchor

I have 250 gallons of gas... Full tilt would probably burn through it in a few hours! I would also only be going about 30 mph!

 

[ftl900]

Re: How much GAS would I use on in a day on the lake

1/3 out, 1/3 in, 1/3 reserve . . .

Either that, or a 5 gallon gas can set aside as a safety measure until you get the feel for how far/long you can go.