I've also noticed a sudden change in pinging after an oil change, but I don't remember which brands it was. Maybe it depends on how much is getting burned. Would PAO lower the octane rating when mixed with fuel, more than a conventional oil?
Advance Auto Parts is currently offering a rebate on a case of Havoline, bringing the price down to $1.28/qt. Limit one case per household.quote:
$1.38 for Havoline, buy all you can because it will only get more expensive in the next few months.