I use Honda 2 stroke oil in my hobbit and castrol 2t in my motobecane, both mixed at the factory specs. I have never had any trouble with either of them. I'am interested in trying synthetic...but I have a good supply of both brands, so untill they are gone thats what I will use. Back in my mispent yout I put over 8,000 miles on a stock moby using castrol 2t. Never an engine prob of any kind. Best of luck with your choice!