i had ran out of gas for my trimmers today and i had my can of 2 stroke mix in that i use for my dirt bikes. it is 60% racing gas and 40% 93 octain. so i used that and i could not tell you how much more power it had. then i put some in my stihl 4 mix and wow what a difference in power. i will be running my racing gas mixed with 93 pump gas from now on. the difference in power was like almost double. i am gonna now run like this all the time.. try it.. you get racing gas at any motorcycle shop. it is like $45.00 for 5 gallons and worth it.