Weird, my 40 year old Stihl runs fine on pump gas, E10. I've not tried the syn fuel yet but have used non-ethanol. Couldn't tell the difference in either, but maybe the syn gas might run better. Full disclosure on the Stihl, i modded the exhaust and tuned the carb when i first bought it, so that might make it run different. Is there a shelf life on the opened or unopened syn gas?
My non scientific swag, showed worse mileage with E85, but better lugging and nice exceleration. Tried non-E one time when i was getting some for my smaller engines to try out, and didn't really notice any difference between the E10 and non-E.
Why I switched to syn fuel. Not cheap but the in tank life is at least 5 years and no gumming up the works.
You have to 'mod' a late model Stihl as Stihl has succumbed to the noise police. I open them all up. 5 years minimum on syn fuel. In the tank or in the can.
That must have been a while ago. I've been buying ethanol free for my small engines for years. It used to be just small independent stations selling it, but yesterday I noticed one of the big chains is offering what they call "Recreational" gas. Most places it's been 90 octane, my sled takes 91 but it's got a newly designed engine so should be able to handle ethanol.
Cheaper to separate the alcohol from the gas. Use that in your small engines. Pour the 10% you got from your gas can into your auto in hot months.
