What octane is best, and why

[Rogee]

Same as us then Markus, although no pump 100 here except aviation. Interesting that you have no 'Regular or 91' option. European cars tend to 95 tho ay.

NPD in the south island here has 100 at the pumps

 

[LoneOak]

For all the Ethanol haters out there!

 

[Kiwioilboiler]

I generally run my Mazda turbo on it because it seems to like it and just get the same for all my saws woodspltter etc

The MPS has sensors and a confuser to make use of the extra octane.
I doubt the other stuff does. If you have trouble starting them with old fuel then the aged 100 should have more pop left, but you are a high user so I doubt that's probable either mate.
If it's bulk delivery 100 stay as is. Otherwise I think you're overpaying for the equipment fuel is all.

 

[Nutball]

I thought I had recently read where the USA limits benzene to .6% in gas, but this guy in the above video says the station uses up to 2.3%

 

[LoneOak]

He is reading it from an MSDS

 

[Muad]

People hate on 100ll...just curious...I'm pretty sure all gas had lead in it back in the day. Many of those people are still alive and well. Now I'm not promoting lead I understand in general it's dangerous. But is running 100ll in your saw a death sentence?

All I run is 100LL. In my saws, weed eaters, log splitter, generators, etc. Basically, if it ain't got 02 sensors, it gets 100LL.

I know it's more expensive (I think my last fill up was $4/gallon at the local airport).

It may not be the "best" fuel, but it doesn't go bad and I hadn't had any carb issues since ditching pump gas for it.

 

[FergusonTO35]

Stabilizer in gas, Power Service in diesel and no problems for 20+ years with this routine.

 

[5155]

Is Sea-foam good for stabilizing gasoline AND diesel?

Maybe that is what had settled out of my saw fuel.
We have to Blame something.

 

[pbillyi69]

Is Sea-foam good for stabilizing gasoline AND diesel?

Maybe that is what had settled out of my saw fuel.
We have to Blame something.

what color was it? white?

 

[5155]

Clear, oil like bubble in the bottom of the red fuel in a jar.

I since have new no-e in a different gas can. Will dump all 2 strokes to check. Much easier than fuel system servicing. I'll still run that fuel after settling out but not let it sit in anything.

The local auto shop says that is the best fuel around.
I have doubts about that.

Another friend manages a fleet of trucks.
He says the stations with newer tanks,
that are selling volume, is best from his records.

All we can do is do are best and pay attention.

 

[5155]

The sea foam can is white lol.

 

[davidwyby]

@LoneOak Yes...I guess we should say ethanol, ETC...regardless, pump gas is kinda bad juju for carby stuff that may sit.

 

[huskihl]

Maybe that is what had settled out of my saw fuel.

If there is water already present in the fuel, I have seen Seafoam turn that water bubble into a gel. Seafoam isn’t going to help if you have water, and I don’t know if it’s a good stabilizer or not. Not certain. But it’s a great cleaner for the inside of the carburetor and engine

 

[pbillyi69]

here is something i learned today to share about octane. i had been having trouble getting a saw that is brand new to tune. i had 100ll, 50:1 and it would not rev higher than 9300. i had forgot that i mixed some to blow off the leaves the blower didnt run that good on it either. i took the half gallon of mix and combined it with a half gallon of efree 92 added the oil that needed to be added and has an end result of 94 octane slightly leaded fuel. the saw now tunes just fine and the blower runs really good as well

 

[davidwyby]

I think 100 is too many octanes

 

[pbillyi69]

avgas is rated at 100 but its calculated different for airplane. the rating of octane the way its calculated for cars it comes out to be 96 then blending in equal portions of av and gas it ends up being 94. however i just ran that saw again and it was back to the same thing. i think maybe the plug wire was being pinched against the top fin of the cylinder and it was messing with the reading on the tach. because when it took the covers off to zquirt some carb cleaner around checking for an air leak i noticed a spot in the wire that was dented in. it moved it and put all the covers back on and back to reading right on the tach.......the damn thing is becoming frustrating to figure out wtf.. 100 is too much though i agree with that because the blower doesnt really perform as good no matter the carb setting

 

[Muad]

avgas is rated at 100 but its calculated different for airplane. the rating of octane the way its calculated for cars it comes out to be 96 then blending in equal portions of av and gas it ends up being 94. however i just ran that saw again and it was back to the same thing. i think maybe the plug wire was being pinched against the top fin of the cylinder and it was messing with the reading on the tach. because when it took the covers off to zquirt some carb cleaner around checking for an air leak i noticed a spot in the wire that was dented in. it moved it and put all the covers back on and back to reading right on the tach.......the damn thing is becoming frustrating to figure out wtf.. 100 is too much though i agree with that because the blower doesnt really perform as good no matter the carb setting

I was gonna say, that makes no sense that it's running like crap on 100LL and OK with some pump mixed in. Sounds like another issue is amiss.... pun intended :0)

All my saws run really well on it, and they all tune fine.

 

[pbillyi69]

it doesnt make any sense to me either if it werent for the blower not being as responsive with the 100ll on the throttle. i have ran it before the other thing with that batch of gas i think it was 40:1 amsoil. i had to retune the blower to make it run right, retune it after i switched the gas

 

[Muad]

That's odd to me. I could see maybe some fine adjustments needed, but I've never had to touch my blower or weed eaters from "factory" settings with my 100LL mix.

I run approx. 40:1 in everything. Basically, I fill one of the small stihl 2.x ounce oil bottles to the rim, and then mix that with one gallon of fuel.

 

[rogue60]

It's a myth higher octane fuels burn slower and lower octane burns faster and makes more powers.
All higher octane fuel has is more of a resistance to pre ignition.
Flame front is as fast as low octane fuel and it can even be faster in some higher octane fuel depending design/purpose like race fuels and the like.
I'm talking e-free fuel ethanol has less energy than gasoline. Another big negative for ethanol laced fuel used in ope is ethanol boils at 78 celsius. Cutting on a summer day here with temps around 40°c doesn't take long for saws to vapor lock.
All they have done is contaminate our once good pump fuel for ope with that ethanol rubbish IMHO.