Whatever you cut and paste from Sunoco is fine, but the fact still remains that not all gasoline deteriorates in octane value with storage. It all has to do with how the apparent value is obtained.
High octane fuel?
- Thread starter slybunda
- Start date
No it has to do with the chemicals blended in to pump gas and they all use volatile gases to obtain their blends and they vary it with the season and in some cases with the region. My excerpt was from Sunoco but you can find similar publications and results from all the major brands of automotive pump gas. Now if you are using Av gas or some special unobtainium fuel as your basis then it does not answer the OP's question.
And why is that? Compression ratio is not impacted by engine RPM. I run Tru-Fuel premixed 50:1 in all of my Stihl equipment. Am I missing something here?
Running higher octane fuel in small 2 stroke engines is important only because they cannot tolerate preignition. Even if they can run on an 87 or 89 just fine the higher octane give you a cushion incase the fuel has started to degrade or run lean. They are so sensitive that Stihl and Echo will deny warranty coverage if they see any sign of preignition. I dont remember if it was stihl or echo that would double their warranty coverage if you bought their engineered fuel when buying their chainsaw or string trimmer.
My local Stihl dealer doubled my warranty when I bought a bulk order (12 small bottles) of 2 stroke oil. Nothing mentioned about fuel. The tech said 87 E0 if I can, but as stated before I use 91 E0 Top Tier.
One thing to consider in 2-stoke mixes, is that the octane drops as oil is added. While a 32:1 or 28:1 may be best for power and longevity - the octane will drop even more than the 50:1 or the silly 100:1 mixes. I buy the highest, best quality NON-ETHANOL (top tier if available) 91 octane usually and Motul 800 at 32:1 and I am beyond impressed with the power, low carbon, great lubricant film left over on surfaces, low smoke and did I mention power?
I am not sure its easy to make a 2-stroke 'ping' - but you sure as hell can make pre-ignition happen with a modified 2-stroke motor. This works for my hotsaws, weedeaters, blowers - all of it. I am doing all I can to use the best, and it does not end up costing me much more.
I am not sure its easy to make a 2-stroke 'ping' - but you sure as hell can make pre-ignition happen with a modified 2-stroke motor. This works for my hotsaws, weedeaters, blowers - all of it. I am doing all I can to use the best, and it does not end up costing me much more.
Preignition has nothing to do with octane. I think preignition is being confused with detonation, where octane does matter. Preignition happens (as you would expect) before the plug fires. Detonation/ping after plug fires. Preignition can kill an engine quick (broken piston/bent rod). Detonation is a little more forgiving as it takes awhile to melt ring lands and cause rings to seize. Fun facts-...propensity for detonation is proportional to piston diameter, and engine load, and inversely proportional to RPM.
2 stroke timing is changed via adjusting the squish and height of the transfer ports in the cylinder - and of course correspondingly moving the ignition coil pickup to match.
Isn't TruFuel a 92 octane?
What does that get you?
What’s expensive???
What does it get you?
4WD
$50 site donor 2024
I run that TF can gas … my Stihl is my last 2 stroke anything so it’s worth it to me. Also grabbed a 15 amp electric last year that saves wear on the Stihl and my ears …
