I'm in CA, so we only get CA91 octane gas here at the regular gas station. I've been recommended to mix half a tank of 100oct with half a tank of 91oct when I'm on track (HPDE). Or even use a full tank of 100oct. I know it's good for safety by means of avoiding detonation and etc. (coming from turbo AWD vehicles) but will it increase hp and tq? I've been told that yes, it will. And that surprised me as my past experience tells me an opposite. Unless vehicle is equipped with octane sensor there shouldn't be any significant increase. Or it should be specifically tuned for 100oct.