I have been ponderin about this also.. I use regulary everyweekend.. cept durin field work and harvest time.. my fishin boat .. its a got a ole 5 horse and a i gots the weedeater.. with a plywood blade for trimmin .. and then the jonnyred52e saw..And i just purchased a stihl 011av off of ebay.. i read that most of everyone is using stihl oil for chainsaws.. Is this gonna damage my engines in the long run? i have been using marine 2cycle mix 50.1 for everything.. am i in the wrong? i just dont like to have 2-3 different gas cans sitting aournd.. i make a 3.5 or 5 gal mix for everything