If a goodly percentage of the population started buying exactly 4 gallons a pop it would get a little crowded at the station BUT it would send a strong message that folks are starting to band together on this issue.
What would buying exactly 4 gallons accomplish other than not giving me time to wash my windows while filling and making me go to the gas station every week instead of every 2 1/2 to 3? It might tell them we’ve banded together, but it would also tell them we’ve banded together for the simple point of banding together not to actually do anything.