What is the highest compression you can run on Pump Fuel? Without getting any knocking or Pre-Detonation?

 

here in Ky generally its said about 12.5:1(max) on 93 octane(thats the highest we get) and thats with a lot of tuning but in cali i've heard you all only get like 91 octane so your probably not gonna want to go as high maybe only like 11.5:1