[zactx]

I've noticed in my 04 2.4 S60 that especially here in the Texas heat with the a/c on, I can hear a noticeable 'ping' that lasts for a second or two on heavy acecleration if I use anything lower then 93 octane gas. I've never heard the noise using the high octane stuff....and it might be in my head but I swear it's not as quick if I run regular. So, despite $2.99 a gallon prices (when i moved to TX 6 years ago it was $.85), I run the good stuff.