Lots of Circle K's in St. Louis. AFAIK, they're all Shell stations. I think the Shell oil corporation is in the process of selling all its U.S. gas stations and convenience stores to other companies. Like ExxonMobil, Shell wants to get out of that part of the business.
Before Circle K bought the stations/convenience stores from Shell, the stations/stores were known as CFM ("Convenience Food Mart" by Shell).
The Circle K's I've seen compete vigorously with QuikTrip ("QT") when it comes to price. I visit both. Wow, Quik Trip sure does offer a great convenience store "experience." Nice bathrooms and lots of hot, fresh-cooking foods. Nobody does it like QT.
Like Circle K's Shell, QuikTrip gas is also TopTier-certified.
Speaking of QuikTrip, what do you all think of the quality of their gasoline? Does your car run well with it?