Octane question

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
I believe the reference may be to research octane, which is always higher than the motor octane. The octane listed at the pump is an average of the two. 87 octane at the pump is generally about 89 research octane. But it will not hurt your engine to run higher octane; just your wallet.
This is from my Echo 361p manual

Gasoline - Use fresh (purchased within the last 30 days from the pump) 89
Octane [R+M/2] (mid grade or higher) gasoline known to be good quality.
Gasoline may contain up to 10% Ethanol (grain alcohol) or 15% MTBE
(methyl tertiary-butyl ether). Gasoline containing methanol (wood alcohol) is
NOT approved. Use of ECHO branded fuel is recommended to extend
engine life in all air-cooled 2-stroke and 2/4-stroke hybrid engines.
Two Stroke Oil - A two-stroke engine oil, such as ECHO branded 2-stroke
 
Seems to loose punch and running time why is this?
Lose, not loose. But the reason is that the more volatile molecular weight fractions evaporate first, leaving behind the less volatile fractions, which do not burn as fast. Think of trying to run a gasoline engine on kerosine. Granted, that would be an extreme case.
 
Lose, not loose. But the reason is that the more volatile molecular weight fractions evaporate first, leaving behind the less volatile fractions, which do not burn as fast. Think of trying to run a gasoline engine on kerosine. Granted, that would be an extreme case.
So how much would an air tight gas can help with this evaporation?
 
While IQ’s have peaked and started a decline in many Western Europe countries, that is not the case in the US.
More importantly, we are falling behind almost all developed countries in terms of real education. We are particularly weak in math and sciences, but not too well in History or Geography either.
 
So how much would an air tight gas can help with this evaporation?
If it is really air tight, it would stop it. But plastic cans still allow some evaporation due to perfusion through the plastic. Still, I use them because they don't rust. There can be some oxidation of fuel from the oxygen in the vapor space, but it will be minimal in an air-tight container.
 
I quit using plastic cans because of the way they swell up and collapse with heat and cold. I use the just-rite or eagle metal safety cans with the spring loaded lid. They can burp if the pressure gets too high.
 
The Echo manual says to use at least 89 octane gas, with a maximum of 10% ethanol.
I only have 87 octane e-free fuel around here (I'm not going to pay $11.25/gallon for 110 octane e-free fuel thats sold near me).

Should I just use 93 octane @ 10% ethanol and call it a day?
Or will adding something like (Lucas Oil octane booster) to my 87 octane, e-free fuel serve me better?

I already plan on draining the fuel tank and running dry for storing my Echo CS-620p any length greater than 3 days.
I know the optimal solution would be to just use 89+ octane, e-free but I just cant find any within 45 mins+ drive.


Thanks for your time fellas!
We only have 87. Always ran it and Stihl mix both types. I ran my first Husqvarna with 87. And I heard the 5 series saw adjust for dif oil. . 50:1or just shy.
 
Back
Top