First off, i agree with Jack about the Ethanol. I read stories all the time on a tractor forum that i'm a member on about the problems folks have.
Having said that, my 95 JD mower, 86 TroyBilt tiller, 2 Stihl chainsaws & one big whopping weed whacker have been running on this stuff for years without a problem. I don't add any additives to it except during the winter when the mower & tiller are stored, i'll start them once a month for the heck of it.
I started the chainsaws over the weekend & ran them for a few minutes, they haven't been used since February, the weedeater works year round being i clear fence rows with it during the winter.
The saws & weed whacker are over 10 years old to boot, i can't fiure out why i'm not having the problems everyone else is having, tried 100% once in the saws & they ran like crap, would have had to carried them to the dealer if i continued, went back to the "E" stuff, no problems.
As i stated earlier, i don't like the politics of the stuff, i'm just not having the problems everyone else seems to be having.