How long is too long before treating a gas tank with additives?

[Ki Ki]

Lets say we go 1 month at a time without using the boat, it's only a 6 gallon gas tank so it gets fresh fuel added each time out. Is that too long to wait without adding treatment to the remaining 3-4 gallons or is it really if it just sits for a few months or more?

 

[Chris1956]

Re: How long is too long before treating a gas tank with additives?

I would not expect gasoline to go bad in a month. I think you are fine.

 

[oldjeep]

Re: How long is too long before treating a gas tank with additives?

It can sit for 8 months and shouldn't have any issues. We don't add any snake oil to the tanks of any of our seasonal toys/equipment.

 

[Another retired guy]

Re: How long is too long before treating a gas tank with additives?

I agree you're ok for 6 months or so. The problem is that if you keep on using some, and then topping off, etc. , the gas gradually ages. With a 6 gallon tank, I would run it low in the fall and then drain it ( put the gas in your car ). Start with fresh gas each year.

 

[MH Hawker]

Re: How long is too long before treating a gas tank with additives?

Thats one of those questions that often gets kicked around and, you will see opinions both ways some use stabilizers and others don't. E 10 can start to phase separate when it is exposed to air in around 30 days or so. In a sealed tank it will last for years. Most boat tanks are open vented so adding a stabilizer when you add or fill is a good practice this time of year when use starts to slow down. I start adding it just so I don't have to worrie about it later when it comes around to winterizing time. I use sea foam in mine for several reasons, my boat is slip kept and fueled at the marina so water can be a problem and it de carbons the pistons, and being as I run real gas it helps keep the fuel system clean. I add 1/2 oz per gallon instead of the 1 oz per gallon recommended for a 1 year storage. I will start adding the 1 oz mix around October and then pull it off of the slip in November, but my boat isn't likely to sit longer than 4 mouths. My season is February to November

 

[Texasmark]

Re: How long is too long before treating a gas tank with additives?

Man you opened a can of worms. Everyone has their opinion and experience. I came on this site back in 2004 time frame and never heard of Sea Foam additive for 2 stroke fuel systems. I used it and haven't been without it since. Besides that, I have resurrected a 2 stroke garden tiller, chain saw, and weed eater with the stuff. I use it in all my 4 stroke engines on the farm and in my 2011 Chev p/u. Very obvious results with all of them. I am sold. Results are immediate and obvious.

Got some penny pinchers that read the MSDS and decide to mix their own. Fine. Their choice. They are doing the best they can do, or choose to do.....redneck syndrome....Grin. Thankfully, I am not that financially strapped and can afford the product from the mfgr,, not having to consider what type mineral oil, what naptha of the hundreds out there, what alcohol percentage and all that.

On the additive time line, as others have said, short term is ok other than the engine enhancements you get running it anyway....not just considering fuel stabilization. Some folks run SF and Stabil. Some only run Marine Stabil.

Gotta make up your own mind. Try this and that. Go with what works for you .

Best I can do.

Mark

 

[pckeen]

Re: How long is too long before treating a gas tank with additives?

I would use a stabilizer after a month with regular gas. If you use premium gas, it will last longer before separating. I've found longer than a month with regular gas, I started to have problems (in an old two stroke).

 

[agallant80]

Re: How long is too long before treating a gas tank with additives?

I have let my boat sit for about 4.5 months without anything in the tank besides the pump gas that was put in it. I did not have an issue with it. I think the question is if I do have a fuel system issue in the future will not using the stabilizer and storing the boat have caused or contributed to the issue or not. I think most people do it so they can say the fuel did not cause the issue if they have a fuel system issue.

 

[JimS123]

Re: How long is too long before treating a gas tank with additives?

Lets say we go 1 month at a time without using the boat, it's only a 6 gallon gas tank so it gets fresh fuel added each time out. Is that too long to wait without adding treatment to the remaining 3-4 gallons or is it really if it just sits for a few months or more?

Regardless of what the experts here say, I think the general consensus is the gas stays fresh about 3 months.

 

[JimS123]

Re: How long is too long before treating a gas tank with additives?

I agree you're ok for 6 months or so. The problem is that if you keep on using some, and then topping off, etc. , the gas gradually ages. With a 6 gallon tank, I would run it low in the fall and then drain it ( put the gas in your car ). Start with fresh gas each year.

If you have a recent model car with a puter and all those darn sensors, if the gas is premix 2 stroke it would be foolish to put it in the car.

 

[JimS123]

Re: How long is too long before treating a gas tank with additives?

It can sit for 8 months and shouldn't have any issues. We don't add any snake oil to the tanks of any of our seasonal toys/equipment.

My Dad feels the same way - he wouldnt pay extra for that darn stabil. He never had a problem either.....LOL>

 

[JimS123]

Re: How long is too long before treating a gas tank with additives?

E 10 can start to phase separate when it is exposed to air in around 30 days or so. In a sealed tank it will last for years.

"Regular" gas won't hold water. If you get water in the tank you got a problem. E10 WILL hold water and run fine. If you get "phase sep" with E-10, if you had reg you would have been dead in the water long ago.

Regular OR E10 will go stale in 3-6 months, no matter how well the tank is sealed. My OEM manual for my 1955 Mercury Outboard said you needed gas stabilizer over winter of the gas would go stale. So, all the discusions we have today is old news. We Boatmen knew that 60 years ago......LOL.

 

[NYBo]

Re: How long is too long before treating a gas tank with additives?

If you use premium gas, it will last longer before separating.

Untrue, AFAIK. Octane rating has nothing to do with the process of phase separation. It is no longer true that premium fuel has more/better additive packages than regular.