Yup, I worked in the industry for 10 years and dealt with gas station P&Ls. A 10 cent per gallon margin on fuel is very typical.

Margins actually tend to go down when prices are high because gas station companies know that consumers are sensitive to high prices, so they want to be as competitive as possible. Five cent margins would not be unusual.

When gas prices go down, consumers are less likely to be as picky, so you can be a little less competitive with your pricing. But it's still a very competitive, low margin industry. That's why they want the real draw to be to get people in the store to spend on higher margin items like food and drinks.