It's all about the additives, and how they clean & lubricate your system.

Heck, even Chevron doesn't make their own gasoline today. They just license their "recipe" for Techron and have it added at the regional distribution center where all the bulk gasoline waits to be delivered.

Also, you want to go to station that has high-turnover. Which hopefully, but not always, means that the station's pump filters are being changed regularly.

Lastly, stay away from a station that is receiving a load/dump of gasoline in the grade you want, for at least 24-hours.

Dumping the fuel causes all the sediment/crap on the bottom of the tanks to mix. Waiting 24-hours allow it all to settle-down again. It's just like dumping water into a pail full of water and mud on the bottom.

:-) neil