I've commented about compression ratios in our Mo's a few times....
We have a 10.3 to 1 compression ratio engines. That is unusually high. Standard engines use 8 to 1. The higher the compression, the easier it is to preignite low octane fuels. Hence the standard 8 to 1, so you CAN run low octane without ping....without a compensation for timing like our engine uses.
8 to 1 engines can't make use of the added power of higher octane fuels. It doesn't hurt, it is just somewhat of a waste to use high octane in low compression engines. In our engine, higher octane use:
A. gives it more power
B. allows it to combust fuel without timing compensation
If you cruise a lot, I would think low octane is ok. If you are like me and romp it a lot, higher octane is what it wants.
IMHO, any ping is no good--preignition is way different than normal combustion. Normal combustion is like a powerful push on your pistons. Ping is like whacking it with a hammer....sounds just like it too. I don't want any whacking going on inside my engine, ever!
