225,053 bought last week. The 3rd owner. 2nd owner had it for 11years and said he ran 93 octane in it.. My question is the if the car ran that long on 93 octane, and it runs WELL I must add, should I take the if it ain't broke don't fix it approach and keep using 93 or can I ween it down by using 89 octane for a while and then go to regular 87 octane.