I don't know if or in fact that this additive is or is not to the benefit of the fuel keeping, stihl 2 cycle oil I believe has its own additive. I run the higher octane fuel, local outfit was touting no ethanol fuel, so I'll have to check that out again, been awhile. Thing is, I rarely have any carb or fuel related problems, unless it is something that sits a for a long time, like years. Things that don't get run as much season to season, fuel seems stable, maybe not hoses and such, but the saw does sit for quite awhile summer, have not cut now since late sept/oct, 2-3 pulls it will start every time, barring any cracks in fuel or impulse lines. that took me just less than 2 hours the first time to replace, so even thats relatively easy, should go quicker the next time. Its a T-27 (torx) if I recall, will take all the screws out, get the covers off etc.