what i never got is when the price of crude goes up, the price of gas goes up INCLUDING the 18000 gallons of gas ALLREADY IN THEIR TANKS. which they bought at the previous rate
The same thing happens in both directions up and down. The station price changes based on what they last paid. In the end, it all averages out. I ran a Sunoco station for a friend over the course of a year when he was ill and I know how it works.