You can put any amount of gas in that you want. I usually put 5-6 dollars in gas and then get a coke or something that costs around $1. Some of the shops require you to pay in cash, if is one that requires a credit card, I may put up to $10 in the car. The company only requires that the mininum is put in. With gas being over $3 a gallon, it is hard to believe that people get only a bit over one gallon of gas. Hardly would get you to the next gas staton.