Which gasoline??
Something else that I have not seen mentioned: I use stations that are frequented a lot! I figure the busier the station, the more cycles their tanks go through. Some stations are just never busy and I figure they don't go through as much gas in their tanks. More deposits in the tanks??
An engineering professor of mine many years ago told me the same thing: Go to a busy station that turns over their tanks frequently. Other than that, use 93 octane (here in AZ, 91) or higher, and find the lowest price close to home.





