Exactly.Higher octane is for higher compression engines to stop pinging.
It slows down the detonation is all. it has nothing to do with like explosiveness / power of a gas if that's what your thinking.
These stock motors are 9:1 compression so 87 regular is fine for that compression rating.
Avoiding Ethanol if possible is actually more important for performance than anything.
@ 11:1 compression of my wiseco in my bike its recommended 91 octane to stop pinging that's the only reason.
It's the extra compression itself that gains the HP in the high compression motor it needs higher octane so it doesn't break due to too fast of a explosion, it has nothing to do with the higher octane gas being more explosive itself.
It gives the gas time to expand when detonated due to more compression and less top stroke cylinder clearance.
One thing i do know however is shell for example doesn't put ethanol in their 91 premium here in canada although its getting harder and harder to find ethanol free gasoline now a days.