I have 18* advanced timing (right now) I had indicated it in my sig until that dumbass PatScottAKA99XE singled me out and removed my sig.bahearn said:So far, not one person paticipating in this thread indicates that 90+ octane is really needed in their cars. I suspect that many of you who claim to have advanced your timing didn't follow the procedure in the FSM and you gained nothing by turning the distributor. The ECU can do a lot of adjusting on its own, so if you don't get the ECU in diagnostic mode, you'll get nothing.
Even still, I have my timing set to 17º on my SE-R and ran 87 octane exclusively on the street. I never detected any pinging or rattling, the hallmark sounds of detonation. For track days, I ran 91 octane only due to the tendency of the car to overheat.
If you aren't turbo or squeezing, stick with 87 octane. Anything else is just a waste of you modding budget.
If you're running 87 octane, with 17* timing, chances are it's not at 17 anymore. When you change to a lower grade fuel your ECU senses it and it automatically retards the timing. That's why you don't have pinging. I learned this not too long ago. If you are currently running 87 octane, I almost guarantee you that if you were to go out right now and check your timing, you wouldn't be above 10*. If you go back to 91+ octane, you will return to 17*.