Pinging with warm engine in hot weather

Reading a bit on decarboning, id be inclined to skip it, for multiple reasons, just try mid-grade gas.

 

It would be easiest and cheapest for you to continue using mid grade fuel, or else experiment with other brands of 87 octane to see if there is any difference.

Alternatively you could install a replacement engine or have the cylinder head removed to scrape carbon off the pistons, but that seems like applying a sledgehammer on a problem the size of a fly.

When I lived in southern CA I noticed mild pinging with the 2004, driving on mild inclines. After moving to southern AZ the problem went away, and mpg improved from low-40s to low-50s. The CA fuel formulation is different for state regulatory reasons.

 

+1
It often does more harm than good.

IF.....your miles are mostly under 40 MPH or so, it might benefit from an extended highway run.

 

I have the same problem on my 2005 Prius and it is bothersome. Did you find a solution? Did you try SeaFoam?