Do you think motor oil has an effect on pinging? I switched from AMSOil 2000 Series 0W-30 (supposedly one of the best motor oils available) to Mobile 1 5W-30 a number of months ago, and although I never thought there was a correlation, I haven't heard any pinging in quite a while. I figured it was cheap Arco and Aafes (military PX) gas that was causing it, but I still use the same fuel and I think the problem has gone away. Maybe it was the oil???