Originally posted by shawmutt
Don't want to start a conspiracy theory or anything, but does your cars say you need premium? Or are your cars tuned for premium?
I'm a GS-R owner, and so while it's not "necessary" to run 91 octane (On the account that my engine has a knock sensor that can retard the ignition if it detects detonation), I consider it good form to use the gasoline my engine needs...