First off who the hell runs a sustained 21psi on their stock ko3 anyways, you know anyone who hauls ass around in 100octane mode all the time??? I know if i had the 100octane program i would only use it when i had to. For the other 99% of the time i would keep in in stock mode, which wouldn't cause any excess wear and tear. You can have up to 4 programs if not at least 3. So you could run in stock most the time, then if it came time for some ass whipping you could use the 91 or 93octane mode. And if that wouldn't GETER DONE you could dropp some 100octane in there for one night. I doubt any serious effects would come of this. Of course there would be some excess wear and tear over time. But even racing your car in general would do this.