I run 94 octane and synthetic oil at a 20:1 mix in my race sleds. It doesn't hurt to run a bit richer with synthetic oils since they burn cleaner than a conventional oil.
GP, THE IDEA BEHIND SYNTHETIC OILS WAS TO LET YA RUN LEANER. BETTER PROTECTION AT A HIGHER RATIO. I TRYED AS FARR AS 80:1 IN MY 77 SRX WITH NO ISSUES. THIS WAS WITH 110 AND AMSOIL. 3:16 (yammie tony)
yes, you can run leaner with synthetic oils, but you can also run richer without harming your octane level, unlike regular oil
I run rich just to be safe, and it seems to work pretty well in my sleds