How important is octane and which 2 cycle oil should I use in my Stihl blower

This should push some buttons! Here is my dilemma, For a while I was using 87 octane e-zero gas and Stihl ultra oil in my Stihl chainsaws, Echo weed eater and Stihl blower. I switched to True Fuel pre-mix for all because the Echo calls for 89 octane (can't seem to find 89 e-zero around here) and the Ultra oil kept sooting up the spark arrestor in the blower. The chainsaws also seem to run and start better. Here is my dilemma, now that leaf season has arrived, I swear the Wife is going through a gallon of True Fuel a week blowing the yard and all the long driveway down to the street. I am not using the chainsaws and weed eater that much so true fuel is fine but I want to switch back to home mix for the blower. Do I need 89 octane in it? What is a good substitute oil for the Ultra? I would like to stay with a fully synthetic oil but still be able to buy at a local store. I have looked at Husqvarna, and Echo oils and they are semi synthetic. Any insight is appreciated!

 

Oil.....

Amsoil Dominator
Honda HP2
Echo Red Armor
Amsoil Saber

I wouldn't worry about the 89 vs 87. Its all I ran in my echo blower and everything else for years until we got 91 e-free here.

 

About these oils...

You can't go wrong with any of them. Some things to consider that may matter to you. The first two are motorsports oils, bikes, atvs ect. No stabilizer in them and no little bottles. Smallest is 16oz for the Honda oil and 32oz for the Dominator. The other two are OPE oils and have stabilizer. They also come in 2.6 oz if you prefer.

It comes down to availability, cost and smell in my opinion as all 4 are excellent.

 

I am currently using Dominator until it runs out and I’ll switch to HP2. 93 efree is available, so I use it. My ope sounds cleaner and crisper on higher octane so I use it. Fortunately I’m in an area where a wide range of efree octanes is nearby.
The 371 Kevin ported for me had a muddy piston top so I finally made the switch from stihl ultra.

 

Yes to this , someone has done a lot of homework so pick your flavor or color.

As far as octane you won't notice any difference , E-free is obviously better.
You need an engine with higher compression before octane comes into the picture.
Higher octane in an engine that can't support it or doesn't need it can actually make less power.

 

There was a big testing series on another site about octane in saws. Out of all the regularly available octanes at pumps, 87 was always the fastest cutting of the pump gas even in ported saws. VP racing 94 octane small engine fuel was right there with the 87 pump. Makes sense as its engineered for small engines. There is more to a fuels burning / power characteristics than octane alone. Sunoco racing fuels has a nice explaination somewhere on their site.

I believe Tree Monkey the saw porter was involved in that testing on the other saw site.

 

This ^ ^ ^!
And yeah, ditch the Stihl oil...

 

I didn't want to say it but yeah, Stihl ultra is....not great.

 

The general consensus, from online reading over the years is, some small engine makers say to use 89 or higher octane fuel because the lower the octane the faster it can degrade. Adding oil to gas lowers the octane itself. How much I don't know and I'm sure that depends on how much oil and possibly the type. Mineral vs Synthetic ect. OPE often sets weeks or months. Fuel in the tank or can, especially if it can vent, loses octane quickly and can go bad in weeks. Higher octane fuel takes longer to reach the spoiled state. Not only because it farther away from that point but also because its refined to a higher standard. (This last bit from the Sunoco site) So, use a good stabilizer or, better yet, for machines you will let set for weeks or months, empty them and run some canned fuel in them to purge the pump gas from the system. Myself, I start them frequently and use PRI-G fuel conditioner unless they are the ones on VP Racing 94 fuel. That stuff is good for 5 years in the can and 2 in the machines tank. I run it in most my saws and my 1/5 scale RC cars.

 

Agree 100%.

 

I bought a metering bottle of the Red Armor today (as per Eggshooterist's advice) and will mix up a gallon of fuel with the 87 octane e-free. I always have about 15 gallons stabilized on hand for the boat outboards in the summer when it is used up fairly quickly and 5 or so during the winter when not used so fast. Before I run the Red Armor I will check the spark arrestor just for grins to see how it is doing on the True Fuel. I saw a YouTube about Echo and the impression I got was that higher octane fuel was somehow related to excess heat and that was why they recommended it. Still doing research and I appreciate all the input!

 

I run nothing but 87 in all my small engines with zero issues. My one blower is every bit of 15 years old and I do some leaf jobs as well as my place. I go through quite a bit of gas between that and my newer blower. I also cut hundreds of cords of wood and just use the 87. Did replace 1 fuel line on one of my saws but that was it. Definitely cheaper replacing that one fuel line than spending money on higher octane and what ever additives are out there.

 

As has been said, I think the Ethanol is a much bigger concern than the Octane for these small engines. Especially older equipment.

 

I mixed up some 87 octane e-zero fuel using the Red Armor oil and filled the blower. I also pulled the spark arrestor and cleaned a minimum of soot out. Wiff immediately grabbed it and went to blowing leaves. Her observations were that the exhaust smelled different and the blower seemed to have slightly more power. I expect the power was a result of cleaning the arrestor and the smell was just the different oil. The picture I'm getting everywhere including our inhouse experts, (Thanks), is that the octane issue is not nearly so important as using e-zero and that there are many excellent 2 cycle oils out there that do much better cleaning than the Stihl Ultra. And that Red Armor is one of the better oils. I'll keep checking the arrestor upon occasion out of curiosity. If it stays fairly clean then the blower stays with the new mix!

 

I run 87 octane corn liquor and Maxima K2. Smells like a day at the races.

Unless you have really high compression and/or advanced the timing the octane isn't going to make a difference in these small engines.

 

I doubt you will have another clogged spark screen with red armor unless you are tuned way to fat and / or don't run them wide open. Probably not even then. It's clean running oil and it will also clean out the trash left behind by lesser oils. My blowers are full throttle way more than not. My screens don't get clogged with any of the oils I listed.

As to the smell, to me it's kind of a sickening sweet smell. Like melted crayons and copper tone sun lotion. I tolerate it's scent when I'm running it to clean old engines. There are far worse smelling oils to my nose though. Like all Klotz oils I've tried.

 

Red armor for me. Bought at home depot among other places. Also, 87 octane pump gas previously treated with stabil and well aged in the rotation.

 

Engineered fuel in the saws for me. All other OPE gets regular 87 with stabil. Except when its getting put away for the year ill run them way down or to empty and fill them with stabilized e free.

 

Thats what I'm doing with the zero turn. Even though the manual states 10% ethanol fuel is safe to use, I won't let it set over winter with it even though I use the fuel conditioner and start it every month or two.

I like the engineered fuel in my saws. I buy a 5 gallon can of it, mix the whole thing and dole it out a gallon at a time. Lasts me a couple years or so.