Winter storage, gas tanks & fuel systems

BroadBand

Since late 60's
Myth: 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 car/boat/motorcycle/engine 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.

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.
 

Th3InfamousI

Administrator
Staff member
Never used it even when In the north..no bikes, mowers, snowblowers nothing. Maybe if more than a Winter but never used it and never had a problem

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Th3InfamousI

Administrator
Staff member
Stabil for me whenever something is stored with fuel never had an issue I've heard some guys say stabil sucks and is useless but then their shit never runs beginning of the season:2cents:
Stabil sucks and it's useless

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Th3InfamousI

Administrator
Staff member
You care to elaborate on this.
It's really just busting Kevin for mentioning that phrase actually.

I don't think it's necessary for anything sitting under a year. I suppose it might be useful if over a year? I just think the claims for gas going bad are exaggerated in less than 12months.

I've never used it in anything and never had any issues. The gas in the shed that sits all winter still works in the mower the next spring.

Growing up in the north we never used it in any thing and that snowblower sits for about 9 months a year and started right up



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BWG56

Guru
I have had gas in my generator for 5 yrs with stabil and it was fine on start up, but I do believe it loses octane, so my 5 gallon cans I fill with premium for the lawn equipment, except the Deere, I run home heating oil thru it from the 250 gallon oil tank in the garage up back. They also make a stabilizer for the fuel oil to keep moisture out and to keep it from jellin.
 

Th3InfamousI

Administrator
Staff member
I have had gas in my generator for 5 yrs with stabil and it was fine on start up, but I do believe it loses octane, so my 5 gallon cans I fill with premium for the lawn equipment, except the Deere, I run home heating oil thru it from the 250 gallon oil tank in the garage up back. They also make a stabilizer for the fuel oil to keep moisture out and to keep it from jellin.
So stabil says it only designed for 24 months! 5 years! Must be the stabilizer...rolls eyes....

Oh now I see they have another product to put in at start up...haha




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BWG56

Guru
So it can last up to 4 years and if you start out with 93, by the time 4 years rolls around your still equal to or above 87:old2:
And as far as keeping your tank full, that's BS also cause you can add an additive to remove moisture during storage also. But if you leave your tank low the tank liner will crinkle and dry out.
 

bdm7250

Guru
Supporting Member
Bikes are never sitting long enough for me to worry about stabilizer, my snowblower which may get fired up once a year still has half a tank of six year old Sunoco 87 octane gas in it.
 

Jwooky

Well-Known Member
It's really just busting Kevin for mentioning that phrase actually.

I don't think it's necessary for anything sitting under a year. I suppose it might be useful if over a year? I just think the claims for gas going bad are exaggerated in less than 12months.

I've never used it in anything and never had any issues. The gas in the shed that sits all winter still works in the mower the next spring.

Growing up in the north we never used it in any thing and that snowblower sits for about 9 months a year and started right up



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^^X2
 

Peckerwood

Active Member
For you guys that claim that Stabil sucks, I'll recommend a product called "Seafoam". I've always used it in a full tank for winter storage, and my bikes have always started up perfectly in the spring and run well on that first tank. Some of you guys claim it's unnecessary to add any stabilizer; that may be true, but for the two minutes of time and trouble it takes to add it, as Dentdude says, it's worth the peace of mind, at least for me.
 

SCOTTx88

Active Member
For you guys that claim that Stabil sucks, I'll recommend a product called "Seafoam". I've always used it in a full tank for winter storage, and my bikes have always started up perfectly in the spring and run well on that first tank. Some of you guys claim it's unnecessary to add any stabilizer; that may be true, but for the two minutes of time and trouble it takes to add it, as Dentdude says, it's worth the peace of mind, at least for me.
I think Seafoam is what killed my original tank liner.
 

kickstart

Well-Known Member
I run non ethanol in all my small engines, motorcycles and old jeep. I fill up my cans and when I get home I add the Stabil and always keep all the tanks full. Has worked for me for many years. Just my .02
 

Viking

Biker
When I want to check gas, I just try it in my 4 stroke weed eater. That thing is super sensitive and without stabil it won't run on gas that has sat for over two months in a plastic gas can. With stabile it will always run. Made a believer out of me.
 
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