Just curious... I usually fill @ Sam's Club, but a buddy told me their gas was sub par.

My gut feeling is that gas is pretty homogenous, but I'm not 100% sure. Due to the high level of intelligence found on these forums, I thought I'd throw it out to find out what the consensus is, or if anyone can point me to some substantive proof that Mobil is better than Exxon, etc. Or if there's a true reason I should be avoiding Sam's Club (BJs back east) to fill my tank.