its time to update my daily driver hatch, and im going to get a zc to give me a bit more oomph (and its actually cheaper to do than rebuilding my d15b2 believe it or not) so in my massive search, im finding all kinds of info on the DOHC zc engine. can someone help clear up some confusion, please =) everywhere i look, i see different zc compression ratios, ranging from 9.1 to 9.6, and some say it depends on if you have a cat or not. whats the deal? If its 9.6 i cant run 87 octane, right? i know the ecu has nothing to do with compression, but will the si ecu's poorer tune help me run 87 octane, as opposed to the 89 teg ecu's tune? some people claim to be running on 87 octane, but at 9.6 compression, it kinda scares me. keep in mind: im not planning on boosting, NAWZing, or anything of that nature. just my daily driver. any help would be greatly appreciated.