<prompt> Human: Okay so I am kind of in a debate with my mother. She says that the smartest thing to do right after you get your paycheck is to fill up your gas tank all the way. I think that that isnt a good idea because then I wont have money later if i need to fill up again. I dont know whether this question actually has an answer, but do you guys think its better to fill up as you go or to fill up when you can? thank you for your time:Edit: Jeez thanks guys. I guess i should have mentioned that I am 18 and I do live paycheck to paycheck. Thank you :  <response>: If you budget is that tight, you need to save more money, make more money, or spend less money.If you kept a 1000 buffer in your checking account it wouldnt matter if you bought gas now or next week. Hell 200 would be enough.From a practical matter, its better to keep the tank closer to full than closer to empty. Its better for in-tank fuel pumps, in cold weather it keeps condensation from making the car harder to start, and if youre ever in an emergency situation where the power is out for a couple of days and the pumps arent working you can still get around. 