found out on car and driver the sti is only 14.5 psi
7-2 2.5L turbo model
The 2.5 liter turbo engine is designed to operate using super-premium unleaded gas with an octane rating of 93 AKI or higher. If super-premium unleaded gas with an octane rating of 93 AKI or higher is not available, premium unleaded gas with an octane rating of 91 AKI can ube used. For optimum engine performance and Driveability, it is recomended that you use super-premium grade unldeaded gasoline with an octane orating of 93 AKI or higher.
not gonna type in the next section but it again warns about low octane fuel, and that you are more prone to hear knocking while accelerating up a hill. (which i do daily)
but as usuall. i dunno
sounds like this experiment is going to waste $12 over the next 6 fillups. lol
when Cody and i used his AP and ecuexplorer he mentioned something about the knock correction number. don't recall what it was, and what it means i still have the logs though.