The brand on the gas pump doesn't mean as much as many drivers think. Luckily, that's often good news when it comes to gasoline quality.

I've had a few emails about the quality of gas at Kroger, Costco or Walmart. Those companies, obviously, don't have refineries and buy their fuel from large suppliers that also supply name-brand stations. 

The supply matrix

The world of pump gas is composed of refiners who create it, jobbers who often distribute it and retailers who sell it to you. That matrix makes a complicated path from refiner to pump, especially when you consider that the local gas station exists as much to capture minimart sales and branded gas card transactions as to sell what comes out of the pump. 

The list of California's biggest refineries isn't even close to a match for every brand of gas station out there: A few refiners supply a lot of stations.

The list of major refiners in California clearly doesn't map neatly to the brands of gas stations seen on the corner. A complicated shell game lies between the two.