I guess you never heard any pinging under load conditions.pinging under steady load is very bad thing and will cause damage over time.now if you only hear or get slight ping in transition loads in part throttle/low rpm thats not so bad as its only a sec or so not heavy loaded.I have replaced many pistons because of detonation issues, its a real killer on turbo cars, broken lands. broken spark plugs etc, its like hitting top of pistons with a hammer .Now Honda not turbo or anything but still pretty high compression ratio, I would never use gas that pings under load, its just not worth it, and retarding the timing is not great either on engine.I would use whatever the manufacturer states the min octane rating, if you want to try higher to see how it runs, it shouldn't hurt at all.The higher grades will have better additives added so that can be side benefit besides octane ratinganyway just my opinion.
