I have always used stihl oil in 2 stroke equipment and I've never had an equipment failure. But, just out of curiosity I'm going to try Opti2. The reason I guess is cuz when I bought my new TCII they recommended opti4 and gave me a bottle of Opti-mixer max fuel treatment. I have been using the Opti4 10w30 in my TCII . I know they are a dealer for the opti products but I began to do some searching on it and figured I'd try it.