FIll up fuel tank for winter??

habit68

Hey Gang, 

I was wondering if I should fill up my fuel tank (ethanol free) for the winter or leave it almost empty, opinions!

I will also put marine Sta-Bil in the tank either way!

Thanks!

habit68

Thanks Alswagg!

Dream_Inn

I fill mine up and add stabilizer.  Then enjoy it for the last weekend, which runs the fuel down a little and gets the stabilizer thru the engines and genny.

Glassguy54

The rationale for an almost full tank is that in an empty tank, condensation can form on the sides, drip down and leave a layer of water in your tank.

MarkB

Glassguy54 said:

The rationale for an almost full tank is that in an empty tank, condensation can form on the sides, drip down and leave a layer of water in your tank.

That's the reason I've always filled my tank, but I've also heard its better to have fresh gas running through your engine the following year, and that a water filter is easy to replace.

What is the better of two evils?

Black_Diamond

Here is the exapnsion fomula, using degrees C:

ΔVolume = (1gallon)(0.000950)(Deg C change)

So take a 342 with 235 gallons at full: storing at 45F [7.22C] and the temp goes up to 55F [12.78F] (delta is 5.56C)

235gal *0.000950*5.56= a volume increase of 1.24 gallons

 

You are not spilling fuel.

212rowboat

Run them to near empty.. put an entire concentrated bottle of startron in it.. top it in spring.. you're good.

212rowboat

You can have as much as a 1/4 tank, heavily treated, and it'll be fine.. I'm a big fan of startron.. :-)

TonyWalker

I have too much time.  But here is my theory.  As the temp gets colder the tank shrinks and out comes the excess fuel.  Any takers on that one?

Tony

Salt Shaker 342

212rowboat

Could be.. my shot: altering barometric pressures create internal pressure which relieves through vent, and altered attitude of boat on rack allows fuel to spill.. or even easier: careless towengine operators tilt and rock the boats on lifting and dropping..

MarkB

Okay so back to the point, what is better empty or full?

Michael T

Near full with startron. I used to fill my tanks right to the top (many years ago) every spring I had to wipe the gas off the garage floor. One year had to dump a few pounds of cat litter to mop it up. Finally got the picture. It does expand and run out of the tanks. Now I fill to about 3/4 to 7/8 and put the startron to it. Marinas, particularly if they are 5 star certified "clean" will kick the sh*t out of you (financially speaking) if you spill gas in their cover all storage sheds, shop or yard. Play it safe. My 2 cents MT

pepmyster

3/4 full plus satb.

BoatAway

at the very end of the season, on what I think might be my last time out, I add fuel stabilizer based on my estimate of whatever happens to be left in my tank at the time. That way the stuff gets in the lines etc. then I store it. Never had a problem and I know countless others that do the same with equal success. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

212rowboat

stabil is good.. startron is good.. fuel dry is good.. none of them are corrosive on their own, and each will treat and attempt to stabilize deterioration of the fuel present...

you're going to get some condensation in the tank... it's inevitable..

whether to store full or empty- in my opinion, pro's and con's lead more to nearing empty than nearing full- IF the remainder of the fuel is treated... the primary reason is that it allows you to provide fresh fuel in the spring (hopefully also summer blend) which is hopefully devoid of water or contaminants..

late in the season, it's been my observation, that fuel points start to closely monitor fuel holding volumes which means they don't own any more inventory than they need.. that's not a big deal, and is savvy... what it means to us, though, is that you stand a good chance of drafting a tank from the bottom of the holding tank, where debris and contaminants like to congregate and procreate, it seems..  maybe.. well, it seems that way..

I wouldn't want that fuel in my tank, which would further degrade over the winter months no matter how much or what compound of treatment you use..

I would, though, want to get a full load of fresh Summer Blend in the spring.. the winter blend uses a butt load of Butane in it.. that butane dissipates quickly, and leaves behind residue and destabilized fuel in the process..

ask your dock to ask their supplier about winter blend/summer blend transition periods.. the deciding factor of what you store over the winter, in my humble opinion, would be based off of that.... if the summer blend is still available, but won't be when you pull it from storage, I'd use it..

whether ethanol laden or not, all fuels are blended differently during different periods of the season.. I think it is LA that has 7 different blends over the period of the year, which is nuts and simply a gov't extortion, in my humble opinion.. the difference in summer and winter can mean the difference in as much as 5pt's RON/Ran, but nobody openly speaks of this.. it can be the difference of as much as 10* spark timing on PCM controlled machines, and another 10* on operating temperatures of an engine- which has a direct effect on economy and longevity expectations of an engine..

212rowboat

......good, quick, easy read here....


I gots a new theory...

Butane has a RVP of above 50psi... winter fuel uses a LOT more butane than summer fuel... my new hypothesis entails that Al cleans up fuel spilled from tanks that topped off with winter blend fuel, as the RVP of summer blend is well below 9psi, as opposed to RVP of winter blend (around 14psi RVP) that is stored in a climate more akin to summer than winter (controlled climate storage >55*f)..

the expansion rate of winter blend fuel could cause spillage by expansion.. the expansion rate of summer blend likely won't, volume to volume...

this, if it holds any merit, would answer the original question with a question: 

Q: Do you top off before storing?  A: if your pumps are still dispensing Summer Blend, not if it has shifted to Winter Blend.


edited to add: there is an even greater reason to ask about the transition of summer/winter:  the winter gas doesn't last as long before staling.. the summer will last longer.. to reiterate what I said in a post before this one- if your dock still has summer blend but will be carrying winter blend in the spring, I think I'd top it off... if the dock has already shifted to winter blend by now, I'd wait until spring to top it.. just my thoughts on the subject, and from a guy who runs his boat all year, so it doesn't pertain to me... :-)

MarkB

I store indoor NOT heated. I probably have 80% in my tank right now. I might go out one more time before I pull her. so my options are 75% or 100% level.

MarkB

?? Any advice?

212rowboat

Use stabil, dry fuel, or startron.. I like startron especially for ethanol laden fuel.. stabil, though, for storage purposes is hard to beat.. dry fuel it in the spring a few days before you fire it..... That's my two cents, anyway.. :-)

MarkB

We use ethanol free fuel at the marina. I added the stabil last night as I don't plan on filling up before I haul in 2 weeks time. I'm assuming it will get mixed in nicely with my next boat ride.

212rowboat

G2g on the recreational gas... It's my understanding that the alcohol is much of what causes fuel to breakdown so quickly.. rec gas lasts longer, all by itself... A chemist I am not, and I understand little of it- all though lately my job has me grappling with the stuff, but...

The alcohol evaporates, but only after destabilizing the detergents and concoction we refer to collectively as octane... It just about has to be stabilized, and this is where startron shines... Stabil is as good or maybe even better for rec gas storage... Dry fuel is good for recovery of fuel that's been wet, but it'll only help you to a degree..

I appreciate the reasons you fellers top off or keep fairly full for storage.. of it were me, though, I'd drop it as low as I could and treat the Hades out of it, or enough to treat a full tank on whatever is left... Then top it in the spring with hopefully summer blend fuel... If summer blend isn't available then, I'd run enough fresh until it became available, then top off..

You fellers using pcm controlled engines will find your spark advancing safely with the summer blend, whereas the winter blend will promote knock.

Michael T

Mark, marinas in our area (four) are all recommending about 80% full and following the advice that Drew gave in the post above re additives. One marina said if your fuel spills onto the fooor of our heated coverall you will have left your boat with us for the last time. Can`t say I blame them. MT

seguir

I've been told as low as you can go and treat and start the new season with a fresh tank of gas. Run it and change your filter.....Why store $$$$ for the winter?

Michael T

Are you ready for this Seguir? Here goes -  If I remember all of the terms correctly - the theory is that there are temperature fluctuations inside the engine compartment brought about by the different co-efficients of volumetric expansion of the different construction materials of the tank and surrounding engine compartment. This results in different rates of heating and cooling between the tank and the fiberglass hull etc.. This then creates "sweat" in empty or nearly empty tanks that forms a lot of water. Having gasoline in the tanks drastically reduces this process. That's what I was told a long time ago by a friend who was a chemical engineer. If he was BSing me for fun then the laugh was on him too as he always kept his tanks at about 90% full - then put Stabil in them (there was no Startron back then). In the Spring he topped them off with the highest octane he could find. Back then it was Sunoco  94 on land or 91 on the water. I've done it ever since, P.S. In our more ocd moments we would change our water seperator filters after a run or two in the spring. MT

seguir

Thanks Michael....This is my first year with the boat and the tank is a lot bigger then my little 18 footer.  So I guess I will be adding fuel before haul out.  The comments seem divided though.  

SeaHare

I store it with whatever is left in the tank, add stabil... call it good, never any problems.

Capt Ron

It all depends on what type of fuel you use.... If you use ethanol leave the tank empty as much as possible.... if you only use marine gas then I would do what Pepmyster does, fill it almost to the top with fuel stabilizer.