RE: Saito vs OS
The only thing about this little debate I know for sure is Who cares about the minor fuel consumption difference anyway, if you do, get out of this hobby now.
Saito engines thrive on 20% nitro, gives great idle and transition.
The Saito .91 is probably the best bang for the buck when you take many factors into account. I know this is a bold statement but my testing of many engines confirms this.