Re: 100:1 Mix
No, Opti 2 is not a synthetic. It is however a new generation of lubricant worth reading up on. I'm curious why you would ask the people at Red Line about a competing motor oil? It's like asking Ford about Chevies. What do think they're going to say? I also think it is wise to assume nothing about something new.
Do what you like and use what you like. if you use something of good quality it probably doesn't matter which is 'the best'. I used to use Amsoil Sabre professional and have been using Opti 2 at 100-1 since last summer. Yes, I live in a cold climate, but others on the forum who swear by it live in California and Arizona and places in the south. If it was wrecking motors we'd be hearing about it from people whose motors got wrecked. I've heard nothing of the sort. Everybody who uses it likes it, seems like. I will keep using it in my bikes and my chainsaws. But that's just me. I think you should use what you're comfortable with.
Someday when I grow up I will probably lose interest in toys with wheels, but until then...