Here is my opinion..... You are better off to use a manufacturer approved oil. I do know that amsoil and redline carry no aproval seals or ratings on them. If your saw goes kaput while running some of this oil, I doubt very highly that amsoil or redline will pay for the repairs if it is the fault of the oil. I know amsoil says they will stand behind the products. Here is my challenge to everyone, Google amsoil versus any oil, or amsoil versus whatever. Amsoil coporate sites always come up first and then distributor sites. Try to find independent testing on their oil.... pretty damn hard eh ? Amsoil spends alot of money paying lawyers and sending out letters to people,websites and companies telling them to retract statements and take their findings off the internet. I personal think amsoil is excellent oil.... but there is better out there ! Try running your new saw on 100:1 amsoil, if it goes kaput call amsoil and call your saw manufacturer....call your dealer, I bet you won't get your saw fixed especially by amsoil ! They have an answer for everything ! If you research it long enough you will see what I mean ! Amsoil seems to brain wash. Run stihl synthetic at the recommended ratio and i bet you will never have a problem. !