Most of the time I get my gas at Chevron or 76 stations. I don't feel like waiting in line 30 mins and fighting other drivers for a gas pump so I avoid AM/PM. I go across the street although I do end up paying more. This morning AM/PM was empty so I thought I was gonna save me some $$$ and I filled the Jeep there. Now ...I have a 2002 Jeep Wrangler with the stovebolt inline-6. Its not a race engine nor does it have high compression. It calls for 87 octain. Ever since I filled my tank this morning at AM/PM I can hear the engine pinging! I drove up some steep hills today and I could hear it pinging. The engine temp is normal but it's rattling like marbles in a coffee can! Is AM/PM gas that bad? I've read that all gas is the same.......I don't believe this anymore. I'm gonna top it off tomorrow with our $3.00 gallon 91 octain gas from Chevron or 76 before I ruin a piston or something.