Winter storage fuel level

[Snobike Mike]

Did a search and read a lot of opinions about what fuel level to store the boat in. Many seemd to talk about metal tanks but mine is plastic.

In either event, it will have stabil added, but the question still is unresolved for me regarding how much fuel to put in. My tank holds 64 gallons. My guess is I have around 40 gallons in there.

On one hand I don't want the condensation issue (if that is a worry), on the other, I'd really like to put some fresh gas in the spring rather than running on 7 month old gas.

So, both choices have their downsides, which is the lesser evil??

 

[fishingdan]

Re: Winter storage fuel level

my opinion...room for air in the tank will be used by air. Air has moisture in it and condensation will collect on plastic too (but not as bad as metal). I like to fill my tank and then use a good stabilizer. Make sure that you run the engine with the stabilized fuel for a bit. You want that mixture through the whole fuel system.

I haven't had a problem in the spring. I do put in fresh fuel as soon as I can. I also use stabilizer year-round.

my $.02

 

[Bifflefan]

Re: Winter storage fuel level

I store mine full, but i have a 12 gal plastic tank.
Id think if you dont store it full and you live in a place where you may get condensation, add some gas dryer and go from there.

 

[lprizman]

Re: Winter storage fuel level

my opinion...room for air in the tank will be used by air. Air has moisture in it and condensation will collect on plastic too (but not as bad as metal). I like to fill my tank and then use a good stabilizer. Make sure that you run the engine with the stabilized fuel for a bit. You want that mixture through the whole fuel system.

I haven't had a problem in the spring. I do put in fresh fuel as soon as I can. I also use stabilizer year-round.

my $.02

concur 100%

 

[rbh]

Re: Winter storage fuel level

I go in the other direction as I have had a tank go bad over the winter and trying to get 125 gallons out of the tank, then do something with it other than use it in an engine is a crying shame.
My vote is use it all up or atleast most of it, put some stabilizer in and run it till it hits the carb, and in the spring run it all through and then change your water/gas filter.
were we are it freezes good in winter, and it does not fluctuate till spring.
rob

 

[45Auto]

Re: Winter storage fuel level

My research leads to storing it full if you're using "real" gasoline, store it empty if you're using an ethanol blend. At 70% humidity (don't think I've ever seen it that low down here in New Orleans!!! ) ethanol blended fuel can absorb enough moisture to go into phase separation in a couple of months. I've had it happen to a couple of cars stored outside for an extended period.

New Orleans Relative Humidity by Month (Percentage)

Morning
Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec.

85% 84% 85% 87% 89% 90% 91% 91% 89% 87% 86% 85%

Afternoon

68% 65% 63% 61% 62% 64% 67% 67% 66% 61% 63% 67%

Ethanol fuel boat article:

http://www.daybreakfishing.com/ethanol-fuel.html

Mercruiser recommends the same thing at the bottom of their FAQ here:

http://www.mercurymarine.com/serviceandwarranty/mercruiserfaqs/ethanol.php#19

 

[Mark42]

Re: Winter storage fuel level

I have read tests that show storing a tank empty can not cause any significant accumulation of water from condensation. I have always stored my boats with the tanks siphoned as empty as I can get them. Never had a problem with condensation, even after spending all winter under tarps in the north with wet humid and freezing weather.

Plus an empty tank can not get "phase separation" from ethanol gas.

An empty tank eliminates all the problem associated with "old" fuel, having to buy additives, extenders, etc.