[jyl]

My wife buys gas at COST because we're there every couple of weeks anyway. And her car's engine shuts off when the car is immobile. I don't bother - too long a drive.

Since COST sells such a high volume of gas, when gas price is rising rapidly I suspect COST's price advantage is reduced. They are selling gas purchased at yesterday's price, while the sleepy station on the corner might be selling gas purchased at last week's price.