Why are you running 93 octane? 87-89 is optimally better. The truth is that the lower octane fuels have better, more optimized burn rate than higher octane fuels on the stock compression engines. You are doing nothing more than throwing hard earned cash away if you do not have a high compression ratio engine. This has been proven here many times over throughout the years. Unless you go into the engine and change components,,, stick with the lower octane fuels, save a buck and get better overall gas mileage.
... just sayin