Gas for the day...

[jlgab345]

We bought our first boat a few weeks ago and will be taking it out (hopefully) for the first time this weekend.

We've never owned a boat, but have been around them for years as both of our fathers have boats.

Most curious about fuel mileage and cost expectations....

We have an '02 Glastron 225GXI with a 5.7l, 270hp engine

We plan to do a lot of tubing, skiing and crusing. What kind of fuel mileage can I expect (prev. owner didn't have an owners manual to pass along) and what fuel will cost me. I don't have any idea how a mile per gallon equates to water...is it the same...X nautical miles per gallon?

Thanks!

 

[CATransplant]

Re: Gas for the day...

It's better measured in gallons per hour. Frankly, you'll be very shocked at how much fuel you will burn. I can't give you actual numbers for your boat, but it will use far more than you expect.

 

[Bart Sr.]

Re: Gas for the day...

For your first time out just fill it up and keep an eye on it. After a couple more times you should have an idea what you will use.With your larger engine I would refill or end my day at about 1/4 tank.

I'm no expert but I did stay at Holiday Inn once.

 

[jafo9]

Re: Gas for the day...

pulling stuff (skiers and tubers) will increase fuel consumption tremendously. just cruising will burn the least. running WOT will be the worst. for a boat there will be a sweet spot where you maximize your efficiency for fuel consumption. it takes less power to push a boat on plane, so after you get on plane, your consumption will decrease and then begin to increase again as you increase RPMs. its different for each motor. some of the I/O guys can probably give you a better idea for your setup.

 

[xjcj3a]

Re: Gas for the day...

if you want an owners manual, email glastron and tell them your model. they helped me out on a 96, since yours is way newer they should have it to.

 

[marlboro180]

Re: Gas for the day...

at least 1-2 gph....

 

[Jacket4life]

Re: Gas for the day...

at least 1-2 gph....

Yeah, and that's a conservative estimate. The thing about a new boat for a man is pretty much the same as a new anything for him. His first instinct is to open it up and see what it will do! You will burn 3-6 gallons in the first hour, I bet! After that, 1-3 gallons an hr. is bout right for cruising, looking around, and occasional skier/tuber. Constant tubing/skiing is more like 3-5 gallons an hr. for that size boat, I would think. At any rate, it a'int good!!! Not with gas at $3 a gallon!!!

First thing to get used to: having a boat a'int cheap!!!!!!!

 

[gss036]

Re: Gas for the day...

1-2 gallon per, maybe at idle. Running or pulling tubers or skiers, probably 10-14 gallons per hours would be realistic. Full throttle maybe 20 GPH.

 

[marlboro180]

Re: Gas for the day...

20 gph????? get real. Sorry that is a little out if this world as an estimate.I think get her out , do it for while and then figure it out....

 

[Summer Fun]

Re: Gas for the day...

20 gph????? get real. Sorry that is a little out if this world as an estimate

No its not with a fully loaded boat.

 

[marlboro180]

Re: Gas for the day...

ok, so maybe not, but we do not know his boat now , do we?out....

 

[Summer Fun]

Re: Gas for the day...

but we do not know his boat now , do we?

'02 Glastron 225GXI with a 5.7l, 270hp engine

Yes we do .

 

[bruceb58]

Re: Gas for the day...

Cruising at 35 MPH probably around 10 gph.

 

[roscoe]

Re: Gas for the day...

at least 1-2 gph....

that would be idling

 

[JoLin]

Re: Gas for the day...

Based on my limited experience with my boat, I'd guess that 10 gph at cruise is reasonable and maybe a bit better than that, but NOT at 35 mph.

Depending on the boat, the "sweet spot" for that motor tends to be in the 3000-3500 rpm range. I cruise at 32-3300 rpm and see about 24 mph on GPS. The OP's boat is smaller and lighter than mine. If he's propped correctly I'd guess at speeds in the high 20's (maybe 30) in that rpm range.

Tubing, skiing, etc? Really no idea as we don't do that. Others can probabkly attest to how consumption rises when you're towing stuff.

My .02

 

[Philster]

Re: Gas for the day...

To understand how ludicrous it is to predict 1-2 GPH, consider this:

Cruising along nice winding country road at 35 MPH, a modern car with pretty good fuel efficiency will burn 1 GPH. That same car might run at 70 for an hour and burn 2 GPH.

A boat?! A boat could burn 10 gallons and log only 25 miles.

 

[bowman316]

Re: Gas for the day...

yea, my boat gets about 5 mpg
and that is a 16 ft boat with a 70 hp on it.

so an hour of running at 20 mph, would burn 4 gallons of fuel. you would be a little higher than that.

 

[H20Rat]

Re: Gas for the day...

20 gph????? get real. Sorry that is a little out if this world as an estimate.I think get her out , do it for while and then figure it out....

Haven't driven a larger boat lately? Thats actually LOW. Yes, WOT is over 21 gallons per hour for the 5.0. The 5.7 certainly isn't going to get better. Looking around, couldn't find specs for that model with the 5.7, but I did find a 235 with a 5.7, rated at 24 gallons per hour.

To the OP... This chart is going to be fairly close for NORMAL cruising. (it's for a glastron 225 w/5.0) Like others mentioned, pull stuff and it goes down. Also, one thing you might be surprised by, but wait until the first time you fill up with the fuel gauge on empty. Boat tanks are SLIGHTLY larger than vehicle tanks!

If you are going for best MPG, keep it at 3000 rpm and you will end up with a cruising rate of around 6 gph/4.5 mpg. (disclaimer, this is for a new boat. Toss in an old nicked prop and and engine with some hours, its going to go down.)

 

[Subliminal]

Re: Gas for the day...

One thing to consider to counteract everything that's been said:

When you're out partying, waterskiing, swimming, you're probably running the engine about 50% of the time. The rest you're just relaxing. So, throw that into the equation.

 

[Tig]

Re: Gas for the day...

The rule of thumb I heard for older boats is 1/10 of a gallon per hour for every horse. So 270hp would have the potential to burn 27 GPH. Based on all the info here this seems high, even at WOT, but if you prepare for the worst you are usually pleasantly surprised at the outcome.