www.toptiergas.com

Anyone use one of the "Top" ones because it's a "Top Tier" gas?
If you use it, do you use them because they are top tier or just cause?
If you use it, do you notice anything better about one of these gasses over others?

Here's the list:
TOP TIER Gasoline Retailers:

QuikTrip
Chevron
Conoco
Phillips
76
Shell
Entec Stations
MFA Oil Company