??Gas tank full or empty??

tisher

Cadet
Joined
Sep 6, 2008
Messages
7
hello everyone,
we are gettig into the fall season and i am looking at winterizing my boat which is my first one. Do i keep the gas tank full or do i drain it as low as i can get it?

Thanks
 

arks

Lieutenant Commander
Joined
Nov 7, 2002
Messages
1,936
Re: ??Gas tank full or empty??

Before ethanol was added to fuel, it was generally agreed that storing with nearly full tanks was the best policy to minimize condensation inside them during the off season.
With the E-10, it becomes a toss-up. E-10 is chemically less stable and is subject to phase seperation, which ruins fuel systems. Since its introduction, I've stored both ways and haven't had any problems. That said, this year I plan to store almost empty, then check my tanks with water-sensing putty in the spring. It's the only sure way to know what's on the bottom. If tests show water is present, then I'll pump the few gallons out and start fresh.
Whatever you do, make sure the gas is stabilized.
 

Joe_the_boatman

Chief Petty Officer
Joined
Apr 14, 2005
Messages
482
Re: ??Gas tank full or empty??

I'd say empty. If you have any problems in the spring with the engine, first thing to toss out is the old fuel, anyway.
 

mthieme

Captain
Joined
Oct 6, 2007
Messages
3,270
Re: ??Gas tank full or empty??

With the E-10, it becomes a toss-up. E-10 is chemically less stable and is subject to phase seperation, which ruins fuel systems.

Phase separation will not happen by itself. If too much water is present, separation will start. Ethanol will displace water which will take care of a little condensation. It will take more than this for separation.
You're safe either way.
The past two seasons we've had gas price scares (lock in that heating oil now!:rolleyes:) with the onset of winter and I've used it in my other vehicles.
 

jaxnjil

Lieutenant
Joined
Aug 3, 2007
Messages
1,368
Re: ??Gas tank full or empty??

i top every thing up and add fuel stabilizer.
adding a stabilizer is more important than the level
i agree 100 per cent that storing with nearly full tanks was the best policy to minimize condensation inside them during the off season.
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: ??Gas tank full or empty??

i store full too. i've got a metal fuel tank that had a mild case of the rustys when i got it. after a few fuel filters i've got rid of most of the rust. since i don't want to go thru that again. i store full to prevent condensation too. w/stabil. in nebraska, best i know i'm still getting premium unleaded fuel. not E10 or E15.
 

109jb

Lieutenant Commander
Joined
Jul 15, 2008
Messages
1,590
Re: ??Gas tank full or empty??

Wherever it happens to be after last outing with fuel stabilizer added before last outing. Done this for 27 years on everything I own that sits for any length of time, cars, boats, snowmobiles, ATV's, motorcycles, lawn mowers, generators, pressure washers,..... Never had any problems. IMO, people make way too much about this particular part of storing stuff.
 

jkust

Rear Admiral
Joined
Aug 2, 2008
Messages
4,942
Re: ??Gas tank full or empty??

Well my boating life magazine says to fill it if ethanol free and empty it if the gas contains ethanol. I called to set up my winterizing this week and they said fill it up before dropping it off. They didn't care what kind of gas I use.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: ??Gas tank full or empty??

We in the midwest have been using #10 since 1997 and it doesn't make a bit of difference which way you do it. Stabilize the fuel, run the engine long enough to pull the mixture into the engine, fog the motor and put it to bed. If you are not using a water separating fuel filter I suggest you add one and then stop worrying about E10.
 

tisher

Cadet
Joined
Sep 6, 2008
Messages
7
Re: ??Gas tank full or empty??

thanks for all the info guys it seems like we could go on for quite awhile about this subject as there are alot of different ideas. I'm from Canada where it gets damn cold in the winter!! the fuel that is available around here i dont think is ethanol added but not sure! never actually paid any attention to that. I've been having some carb troubles with my boat and don't really want to start with a full tank is spring just in case the troubles return so that being said i think i will store partially full with stabilizer in and see what happens!!!

Thansk for all the info guys!!
 
Joined
Aug 30, 2008
Messages
25
Re: ??Gas tank full or empty??

Yeah, I don't like the idea of having a full tank of crap gas in the spring if that ends up being a problem. It might run in a mower (take forever to use), but if it's a problem in a boat, I'm sure not going to use it in a car.

I like fresh gas in the spring. Retailers say a lot of things about their gas, like how long it holds its qualities, what the ethanol content is, or what octane it is. You never know, but it's easier to pull a few gallons rather than a few dozen gallons.

...just be sure to use the right ratio of stabilizer...​
 

krakatoa

Senior Chief Petty Officer
Joined
Aug 8, 2008
Messages
705
Re: ??Gas tank full or empty??

I dont need to deal with the "winterizing" thing since here we have summer all year but If I have to deal with I will go with an empty tank.
 

marine4003

Lieutenant Junior Grade
Joined
Feb 3, 2008
Messages
1,119
Re: ??Gas tank full or empty??

FULL... Right now i get fuel for $3.46 a gal, what it will be in 5 months ?????it takes 150 gal. to fill so even a $.50 increase costs me 75 clams.
 

tisher

Cadet
Joined
Sep 6, 2008
Messages
7
Re: ??Gas tank full or empty??

right now around here we are at $1.229/L. These gas prices are killing the fun seekers who just want to have a few toys. I have a snowmobile which is not the best on gas mileage either so we will see how that goes when winter gets here. Yaa, for four strokes!!:):)
 

Irv964

Petty Officer 1st Class
Joined
May 3, 2008
Messages
315
Re: ??Gas tank full or empty??

I guess this is more of a question than an answer but my way of thinking is this, if you choose not to leave the gas tank full and you indeed get some moisture in the tank over the winter, will not topping up the tank in the spring with fresh new fuel not absorb(so to speak?) what ever moisture is in there?
My tank is just above a 1/4 full and that is the way I plan on storing it, it has been stabilized and not once has the dealer suggested to fill the tank or leave it empty.............Irv964
 

JoLin

Vice Admiral
Joined
Aug 18, 2007
Messages
5,146
Re: ??Gas tank full or empty??

I'm trying to work it out so my tank is nearly empty when I haul the boat out for the season, at which time I'll drain the rest.

At least some of those gas molecules have been in the tank since I first filled it in April, so I'd rather start with fresh fuel in the Spring instead of having residual fuel in the tank that's a year old by the time I wake it up again.

As I added fuel during the season, did the new fuel rejuvenate the old, or did the old fuel in the tank degrade the new? Not being a chemist, I just prefer to empty it all out once a year and start over.

IMO, a well-vented tank should have minimal condensation issues, and that concern can be addressed with some dry gas in the Spring if one feels it's necessary.

My .02
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
16,317
Re: ??Gas tank full or empty??

I have 2 fuel tanks (92 and 47 gallons) onboard. The opportunity exists to fish year round if the weather holds out so I never know if the next outing is 10 days away or 10 weeks away. Once winter comes I keep Sta-bil in the tanks at all times just in case. Come Spring I just top off the tanks and I?m ready to go.
 

FREDDYPD

Seaman
Joined
Jul 8, 2006
Messages
70
Re: ??Gas tank full or empty??

I try to go as empty as possible, add stabilizer and blow out the carbs. I heard that is where the most problems are. In the spring I fill it up or close to it to hopefully "dilute" the old stuff.....I am definitely no expert though.
 
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