I mix up 2 gal. gas today with ,1 oz. Sta-Bil ,(64:1)4 oz. Amsoil Saber Professional and put it in my new Husqvarna 580BTS and it run perfect no smoke and very little smell .As for the power this thing is insane I blew off 2 parking lots in 2 1/2 hours and only use 1 tank of gas vs Before if would all day with my handheld blower ,a shovel, bucket, push boom . With the 580 blew it from start to finish with out stopping . The rock would pile up but I could kelp on going.