Moth Balls
If you are experiencing ignition ping in your engine, the easiest way to do it is to try going to the next higher octane level gas and see if it clears up. Dont go overboard and try mixing 105+ or any of that stuff in your engine. The fact is that too high an octane hurts performance. Your engine only needs just the amount to survive, no more.
I remember back when I was a teenager (the 60's), some guys would put mothballs in their gas, like maybe 5-6 to 20 gallons, supposedly it was a secret elixor to boost horsepower. like tossing in some nitro or some exotic fuel. In practicality, I never saw anyone run any better for the effort, and did hear of some guys getting gummy carburetors out of the deal.