Fuel capacity during winterization?

[Jetch114]

Serial#: 3B099541

I’ll be winterizing my new boat/motor sometime early to mid November and fore her back up in March or April. What are all you guys doing for fuel capacities? I have a 50 gallon tank. In my mind- it seems it would be best to leave fuel tanks close to empty, like 5-10 gallons and treat that amount? Other option is to fill it full but I’m not sure that’s a good idea as then I have 50 gallons of old but treated fuel in March? What do you guys feel is best? Thanks for your input

[XingEyeballs]

I’ve done both when winterizing here. If I can plan it right I run it as empty as I can and load fresh in the spring. If it’s got half or more and the winter crashes in I fill it up full to minimize space for condensation to occur and make sure to treat the gas when you fill and it’s fresh, treatment in “old” gas is too late.

[SilverFox579]

I've read about both views, full or near empty. I treat every drop of fuel per the FAQ recommendation (actually, I use Quickstor year round due to my use pattern) and keep my tank full. Has worked just fine for 12+ years and that's with ethanol fuel.

[swamprat]

Full and done,,And you have a reserve of gas for extended power outages,to run the generator.

[DaveTTN]

I’ve always been told to keep it full to eliminate condensation.

[EuropeanAM]

Benefits (and arguments) for both FULL and EMPTY.

Mercury recommends it be stored one of those two (empty meaning "dry empty").

[MichaelJ3]

FWIW, On year 4 of mine, always fill it to full....to minimize condensation.
I treat every drop w/ QuickCare, QuickStor, and QuickKleen per the bottle dosage, never had an issue.
After a November to Late April store, my 150 4s has never failed to run. I usually make an effort to run that first tank to almost empty before refilling in the spring.
With the humidity and weather changes here, and the frigid cold in the winter, I am certain I would have condensation in the tank if I stored it empty, no way around it.
I don't know how to get it all the way empty...seems like a painful effort...and still likely to miss some, so I have chosen full...so far so good.

Did the same w/ my waverunners for the 12 years I owned them, never one issue related to fuel.

Fuel choice for storage is BP Ultimate ethanol free from a busy station (yes, I know the octane is high on this per the 87 "recommended" but for storage, I think no Ethanol is the way to go).

[Jetch114]

FWIW, On year 4 of mine, always fill it to full....to minimize condensation.
I treat every drop w/ QuickCare, QuickStor, and QuickKleen per the bottle dosage, never had an issue.
After a November to Late April store, my 150 4s has never failed to run. I usually make an effort to run that first tank to almost empty before refilling in the spring.
With the humidity and weather changes here, and the frigid cold in the winter, I am certain I would have condensation in the tank if I stored it empty, no way around it.
I don't know how to get it all the way empty...seems like a painful effort...and still likely to miss some, so I have chosen full...so far so good.

Did the same w/ my waverunners for the 12 years I owned them, never one issue related to fuel.

Fuel choice for storage is BP Ultimate ethanol free from a busy station (yes, I know the octane is high on this per the 87 "recommended" but for storage, I think no Ethanol is the way to go).

This is good to know as I have similar weather conditions to yours.
I think im going to go with our 91 (Ethanol free) octane for winter storage as well. I just dont like the idea of having even 10% ethanol sitting in my boat for months. Seems like the smart thing to do.??

[Paintworx]

I am pretty sure that I am OCD but my program is to fill the tanks to the top with treated fuel going into winter and keep the condensation out and have reserve fuel for emergency (like swamprat). And then here’s the OCD part. As spring approaches I use a pump and remove the fuel and start running it in our cars. We have 5 active drivers in my house so 50g goes fast and everyone looks forward to spring fill ups on Dad. Then I put fresh in the boat. Nothing wasted other than some time and effort. I have 4 of the upright dirt bike style cans so it’s pretty easy. I recommend treated non ethanol for this.

[Jetch114]

Am I over thinking this? I plan to run most of my 10% ethanol fuel out of my boat, Add 5 gallons of 91 octane ethanol free treated fuel, run it through the engine system and then fill the tank full with 87 octane 10% ethanol treated with quikcleen,quikcare and quikstor. In my mind the fuel in the lines of the engine and components will be ethanol free but ill have 50 gallons in the tank for spring that is the preferred 87 octane. Sound legit?? lol

[EuropeanAM]

If you're going that route- this would be the ONE time I would recommend using mid-grade or 91. And only for the one (1) storage tank of fuel.

Your engine does not need that high of an octane- but it does REQUIRE 87 octane. Regardless of treatment, long-term stored fuel will lose SOME of it's octane rating, thus 87 stored for 6+ months should really be siphoned from the tank (and not run in the outboard).

Your car or truck is much better equipped to handle the fuel that's removed.

[Jetch114]

Thank you Don. That makes sense. I’ll fill it with 91 then.

[schinkr1]

If you're going that route- this would be the ONE time I would recommend using mid-grade or 91. And only for the one (1) storage tank of fuel.

Your engine does not need that high of an octane- but it does REQUIRE 87 octane. Regardless of treatment, long-term stored fuel will lose SOME of it's octane rating, thus 87 stored for 6+ months should really be siphoned from the tank (and not run in the outboard).

Your car or truck is much better equipped to handle the fuel that's removed.

I'm confused by the "one time" statement. Is the recommendation to run the lower 87 octane fuel that contains ethanol vs running 91 octane ethanol free? I always thought you wanted to avoid ethanol if possible because it has higher moisture attracting properties and eats away at rubber components within in your fuel system.

[EuropeanAM]

I'm confused by the "one time" statement. Is the recommendation to run the lower 87 octane fuel that contains ethanol vs running 91 octane ethanol free? I always thought you wanted to avoid ethanol if possible because it has higher moisture attracting properties and eats away at rubber components within in your fuel system.

Don't let "one time" confuse you. That's one more time than "never", and one less time than "twice".

Yes: Engines are best run on the fuel they were specifically DESIGNED for. See the following excerpt from the FAQ Section:

www.bbcboards.net/showthread.php?t=591938

Fuel Selection:

Make your fuel selections based on the following criteria, IN THE FOLLOWING ORDER:

-High Traffic, Top-Tier (Name Brand) Fuel
-Appropriate Octane Rating (see above info)
-Lowest possible ethanol content (NEVER to exceed 10%).
-While it may be preferable to utilize a fuel that contains lower (or no) ethanol, use of fuels that are SUBSTANTIALLY higher octane can result in decreased performance, decreased fuel economy, and potential for carbon buildup. Higher octane fuels burn SLOWER and COOLER.

So essentially- Ethanol content is the final criteria (NOT the "first").

[Jetch114]

I'm confused by the "one time" statement. Is the recommendation to run the lower 87 octane fuel that contains ethanol vs running 91 octane ethanol free? I always thought you wanted to avoid ethanol if possible because it has higher moisture attracting properties and eats away at rubber components within in your fuel system.

Id also add to maybe help the confusion- I think what Don is saying is use 91 octane (one time a year)when you do a final fuel up leading into winterization and after months of sitting it’s octane level will diminish a bit.
ideally best would be to find 87 octane with no ethanol.

[Pulsare2020]

I think Don meant to fill it with 89 or 91 octane (no matter if you prefer non - Ethanol or E-10. Both types will slowly lose octane rating over a few months of lay up even with the tank full. So Don was suggesting that if you filled it with 91 or perhaps 89 octane, after the layup is over, if you had the fuel tested, it would hopefully still meet the minimum 87 octane requirement.

[schinkr1]

Not trying to hijack this thread and can start a new one if appropriate as my question wasn't necessarily for winter storage. My manual states "USA and Canada ‑ A posted pump octane rating of 87 (R+M)/2, minimum, formost models. Premium gasoline 91 (R+M)/2 octane is also acceptable for mostmodels. Do not use leaded gasoline." To me it reads that 87 is the minimum and 91 is fine, so I thought using ethanol free rated at 91 year round would be fine. It was educational to me that ethanol free can leave more carbon deposits and not clear whether the deterioration of rubber components is better or worse than carbon deposits and less fuel efficiency. If I found 87 ethanol free would that be preferable over 87 with ethanol? Again, sorry if this is too far off topic.

[EuropeanAM]

"Acceptable" and "Fine" are not exactly interchangeable- especially with "Required".

This has been discussed many, many times here, and we must keep in mind that with only a few exceptions, our 4-stroke Outboards (to date) are limited in what they can do to accommodate changes in fuel octane.

If the engine was programmed for 87 Octane fuel with up to 10% ethanol content (E-10), that fuel (or a fuel as close as physically possible IN OCTANE) will be what performs BEST in that engine.

Excessive carbon deposits can be (and often are) far more damaging to an engine than anything that might occur from regular use of E-10 fuels.

FAR more problems are attributed to ethanol (today) than it is really causing. It has literally become the "catch-all" for anything that falls into the "um... I don't know" category.

[SilverFox579]

Excessive carbon deposits can be (and often are) far more damaging to an engine than anything that might occur from regular use of E-10 fuels.

FAR more problems are attributed to ethanol (today) than it is really causing. It has literally become the "catch-all" for anything that falls into the "um... I don't know" category.