it pains me to ask this question but when you do as much commuting as me lol highway cruising has anyone noticed a massive drop in gas mileage now they have the s/c? and will i have to run on 91 or 94 octane all the time or can i have it set to run on regular gas 87 or 89 octane ? its hard to find good 94 here, everytime i get it i have massive (ping) problems thanks alot all