Originally posted by STiBro
Careful when giving out such vague advice...there's a little more involved. One can only safely mix up to a 30% mix of toluene or xylene into pump gas. And add 1 oz of Marvels Mystery oil/gal of either of the aforementioned is recommended. Both of these are very "dry"...the MMO helps keeps seals from drying and cracking.
Personally, I'm running a 94 octane mix: 1.5 gal xylene (117 octane) and 1.5 oz MMO with 11.5 gal 91 octane. This is safe to use in a daily driver.
Sucks to be in California... many places on the east coast you can buy 94 octane at the pump as the "premium" fuel for no real increase in cost.