The dealer will tell you never to run anything but Yamalube at 100/1 or your engine will explode. But then turn around and tell you to run it at 25/1 during break-in. I have run my 2001 5 hp on regular TC-W3 at 50/1 forever. I use it as a kicker and want it ‘s tank to serve as reserve fuel for my ’66 Merc 20 hp. main engine. I wouldn’t be afraid to run any TC-W3 at 50/1.