Yea all i ever run is chevron 93. And when i say lugging is when im in 4th gear around town at like 3k rpm and going to pull a slight hill it starts to ping. Or any time it is down around 3k rpm and I ease into the throttle to start to accelerate it will ping. The plugs that I have recently put in the car are NGK iridium plugs and brand new MSD plug wires also.Originally Posted by scttydb411