Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

[bruceb58]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

Somewhere between full and empty is what I do.

 

[Ernest T]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

Regardless of who is right or wrong about the water condensation debate, here is why you should always fill the tank for storage: how often in your lifetime have you seen gas prices fall then stay that way or continue to fall.........NEVER. On average the price of fuel will be higher in the spring, so you save $$$ by filling your tank in the fall. Secondly, I hate having to start the boating season with a huge fuel bill. Paying out $200-500 bucks to fill the boat tank really puts a damper on my start of season fun. It will put a smile on your face to drop your boat in the water and wave at all those guys lined up at the dock filling their tanks in the spring as you cruse by with your tank full.

 

[98Shabah]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

Mine has however much was left in it after the last trip out.. I mix stabilizer in with whatever the fuel gauge says is left before running it the last time of the season.

 

[H20Rat]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

I own a Mercruiser and they recommend 9/10's full. It's in bulletins for Mercruisers techs. Fill to 9/10's to leave expansion room and add fuel stabiliaer.

I am currently buying a Mercury Racing Optimax 300xs and -- bingo -- I read the winterization procedures and it says to drain all fuel from the tank.

Just checked the service manual for my sportjet 175. (its basically a merc 175 v6 2.5l outboard block mounted inboard...) Yep, they split the difference! For e10 gas, they say drain it 100% empty. For regular gas, 9/10s full plus stabilizer.

 

[JimS123]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

Chill out.

I own a Mercruiser and they recommend 9/10's full. It's in bulletins for Mercruisers techs. Fill to 9/10's to leave expansion room and add fuel stabiliaer.

I am currently buying a Mercury Racing Optimax 300xs and -- bingo -- I read the winterization procedures and it says to drain all fuel from the tank.

I've posted these finding within the last 45 days in one of these godforsaken fuel threads. I will see if I can repost.

I don't have your owner's manual so i don't know what it says. Maybe its different from their web site. All I know is that the web site says the same regardless of product line.

I would think that web site info would reflect their current thinking.

 

[cyclops2]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

Can I dump out ALL the worms in the can ??

There are 2 possible bad things that can happen to gasoline tanks in the winter.

1 Is the gasoline may need a preservative.
2 Is the heating & cooling of the air in the tank WILL pull in humid air.

Most boat gas tanks are NOT sealed against changes of airpressure & humidity moving in & out. Possible cure is to empty the tank as much as possible to stop that cold gasoline from nighttime temperatures causing "sweating water " on the outside & INSIDE OF THE TANK on humid days......Or fill the tank COMPLETLY. The sweating is scary on the outside. But the small humid air volume available INSIDE the tank, is very small.

1 of the 2 gasoline levels MAY be worse in your area.
I have the Stabilizer put into the empty fuel tank & filled with fresh gas. Hopefully fresh. Minimum sweating. Hopefully.
Not sure if my V8 fuel tank can be really emptied out.

 

[Philster]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

I don't have your owner's manual so i don't know what it says. Maybe its different from their web site. All I know is that the web site says the same regardless of product line.

I would think that web site info would reflect their current thinking.

You're missing the point, because you're too busy worrying about right versus wrong. The point is that the issue at hand is confusing and polarizing; it's hard to get to a single, all-defining answer. That's the point. Ask a Mercruiser tech, and they'll point you to bulletin 12345blahblah which mentions the 9/10's thing and stabilizer. Pull up the website and it clearly says "empty if possible".

It's a polarizing issue. It has two sides, and sometimes the same family of companies has conflicting information out there and it varies whether you speak to a trained expert or read a website. And when you compare information from a variety of sources, it is still a polarizing, hotly-debated issue.

Mine sits 9/10 full with Stabil, and that's about 375 bucks worth of non-ethanol fuel.

 

[cyclops2]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

Upstate N Y has Straight gasfrom Canada again. The marinas got the good stuff first.

In N J my mileage is 15 to 20 % better now.

 

[JimS123]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

You're missing the point, because you're too busy worrying about right versus wrong. The point is that the issue at hand is confusing and polarizing; it's hard to get to a single, all-defining answer. That's the point. Ask a Mercruiser tech, and they'll point you to bulletin 12345blahblah which mentions the 9/10's thing and stabilizer. Pull up the website and it clearly says "empty if possible".

It's a polarizing issue. It has two sides, and sometimes the same family of companies has conflicting information out there and it varies whether you speak to a trained expert or read a website. And when you compare information from a variety of sources, it is still a polarizing, hotly-debated issue.

Mine sits 9/10 full with Stabil, and that's about 375 bucks worth of non-ethanol fuel.

Noooo, YOU missed MY point.

I wasn't debating or even suggesting what was right or wrong, nor could I care less whether you go full or empty. In my first post I made it clear that I had my thoughts and I'd keep it to myself.

Soooooo, I'm not even arguing the point!

What got your ****** in an uproar was the fact that I corrected you! I was not commenting on what Mercruiser Techs have to say - half of them don't know crap anyway, and whatever they say could be personal opinion, not what's the official Company position. They are not the authority!

The fact is that Mercruiser's Web Site is consistent for OB and I/O. THAT was my statement, and that's not debatable. It's there on the web for anyone to read. If your Tech has a different opinion, go ahead and voice it, but don't say the Web Site says different.

The only reason it's polarizing is because there may be more than one way to skin the cat!

 

[Philster]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

Another poster who can't follow the chain of a thread: Please tell me where I said the website said two different things? I stated what Merc Techs and bulletins say, and I stated what I read when I looked up the info (which was on the web site) when considering an outboard.

You didn't 'correct' me; I can follow a thread. You're all over the place: You admit I voice what Mercruiser says (which I hear from techs when they reference their bulletins), but decide to obfuscate by saying that I said the website said it both ways.

Obfuscation Fail: YOU.

 

[Fireman431]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

Here is the lastest info from BoatUS, whose authors have done the research with the professionals in the boating industry. The article title is "3 Myths About Ethanol". Here is an excerpt (note the bold type):

"Myth #1: Ethanol-enhanced gasoline (E10) loses octane much faster than regular gasoline.

Many mechanics believe that octane loss during winter storage could be great enough to damage an engine when it's run in the spring. These same mechanics will often recommend leaving the tank almost empty so that fresh gasoline can be added in the spring to raise depleted octane levels. While all gasoline loses octane as it ages, ethanol-enhanced gasoline loses octane at about the same rate as regular gasoline, according to Jim Simnick, a technical advisor at BP Global Fuels Technology, and Lew Gibbs, a senior engineering consultant and Chevron Fellow. The two men have over 75 years of combined experience working with gasoline and both agree that the loss of octane over the winter would not be sufficient to damage an engine. Note, however, to keep any gasoline, including E10, as fresh as possible; they said it's good practice to always add fuel stabilizer ? an antioxidant ? whenever the boat will be idle for long periods.

The recommendation to leave a tank mostly empty is bad advice; it could significantly increase the amount of water that gets into the tank. When enough water enters through the vent, the ethanol will separate ("phase separate") from the gasoline. Leaving a tank mostly empty does three things to increase the chances of phase separation:

It increases the volume of open space in the tank (its "lung capacity") so it can "breathe in" damaging moist air. An almost-empty tank leaves more space on tank walls for condensation to form. Leaving less gasoline in the tank means there will be less ethanol to absorb the condensation.

It's interesting to note that in areas of the Midwest that have been dealing with E10 for over a decade, topping off tanks is common practice. (As an alternative, completely emptying the tank would eliminate any chance of phase separation.)

If phase separation occurs, the highly corrosive ethanol/water mixture will settle to the bottom of the tank and remain there even after fresh fuel is added in the spring. The only way to remedy the problem would then be to drain the tank and add fresh gasoline. The best way to avoid phase separation over the winter (aside from emptying the tank) is to leave the tank 95-percent full (which allows for expansion) so that there's less moist air in the tank, less space for condensation to collect, and more gasoline to absorb whatever moisture does accumulate".

Here is a link to the entire article:

http://www.boatus.com/magazine/2011/december/ethanol.asp


Do with it what ever you think is best. I always thought it was better to get professional opinions...

 

[Black Snow Slide]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

Internal tank is filled and Startron added. I also tape off the vent. Make sure the fuel in line is treated as well.

 

[tpenfield]

Re: Winter Layup Survey . . . Gas Tank 'Empty' or 'Full'

30+ replies within 1 day . . . such a passionate subject.

I have about 30 gallons left in the tank, which I plan on pumping out and putting in the cars tomorrow. MT for me.