Octane additive to gas

[GaryM]

I've never added octane booster or stabilizer to my tank either. Then again when it gets cold here in NC we don't winterize our boats, we go striper fishing

Gary

 

[coachbob]

I use an ethanol stabilizer often in my tank and have never had a gas related problem. Ethanol can pull condensation and cause water build-up. So I think using an ethanol stabilizer is a good idea.

 

[jeffnick]

I had an old Ford truck that would knock when I was towing using Regular. The knock was absent using Premium. I tried everything on the market to get the Regular to quit knocking - nothing made a difference. My conclusion is that octane enhancers/boosters aren't worth messing with. Of course, YMMV.

 

[stonebuster]

Does anyone ad octane additive to the gas that has been stabilized but has sat for three for four months?

I have never had a problem. My routine is to run stabilized gas for the month of November, fill the tank and ad the right amount of stabilizer and that's it. Ran the tank down in the spring and re filled.

But, how much octane is lost by sittiing-I put in 89 octane before layup?

I use 89 octane and never add any octane booster and have had no problems. My layup period is only 4-5 months anyway and even if it went down to 86 or 87 the manual says my four stroke is happy with that octane rating. I've been told in the past that the 2 strokes need a higher octane than the fours. I do use a fuel stabilizer though.