We've all had this experience one time or another: you're late for an appointment and realize that your gas tank is running on empty, rather than taking the time to fill it up you just put enough to hold you over. For some of us this is more than just a rare occurrence, for some, this happens every time we visit the gas station.

So, are we saving more than just time when we only fill the tank part way or is it better to always fill your gas tank full each time we visit the pump?

Filling up your gas tank may seem like a pretty simple task, but if you were to watch people at the pump you'd begin to notice some nuances to how every one does it. For example: you may be the type of person who plays the market and only puts $20 in, hoping that prices will go down next time you need gas. Or you may fill your tank right up stopping when the pump clicks off. OR you may be the one who always tops up the tank even after the pump has stopped once.