of COURSE you do... As soon as I made my post, I fully expected you to say you use it... heh... but it's still crap gas... have seen a lot of knock retard CONSISTENTLY in data logs over and over and over.... so in that respect, yes, it is consistent...
here's just one of many many many many threads from others that had issues with shell gas... read here starting with this post:
http://www.ls1gto.com/forums/showthread.php?p=6794379