Originally Posted by wag123
Originally Posted by kschachn
Originally Posted by dinofish
Well, it is not a myth, it is my direct observation. I noticed that regular is only good on the day of filling, and after that, it loses its effectiveness. I first tried to retain freshness with 'sta-bil', but eventually tried premium and found it to be far superior.
Which is fine, but it is not due to the octane rating. There are multiple ways to obtain a specific measured octane rating and one of these aspects is contributing to the effect you're seeing. But it is not in and of itself due to the octane number. Octane rating is solely related to the resistance to pre-ignition.
+1
The octane rating has nothing to do with volatility. Gasoline's loss of volatility over time is what causes starting problems. 87 octane gas does not lose it's volatility any faster than higher octane gas. If your engine is hard to start (or won't start) with fuel that is newer than 60 days old, regardless of the octane rating, you have another problem.
I reiterate, the low compression ratio of small air cooled engines does not require a higher octane rating than 87. If a small air cooled engine had a high enough compression ratio to require higher octane fuel, you wouldn't be able to pull start it.
Regardless, if it makes you feel better using higher octane fuel, go ahead and use it, it won't hurt anything.
If it makes you 'feel' that it is all my 'feelings', then go right ahead. You are more than welcome to your 'opinion' vs my direct observation. If it is something else giving better starting with high octane, then address it.
But you can prove it to yourself. Buy two cans and try it with two different fuel types on a small engine after having them both sit for a month. Then you can tell me how you 'feel' about the results. Remember that you have to test it in a small engine. Like a 4-cycle leaf blower, or trimmer, etc. The effects are more immediate and noticeable in smaller the engine.