We've all had this experience one time or another: you're late for an appointment and realize that your gas tank is no 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 occurence...for some, it's the method we use at the pumps every time we visit them.
Which brings us to our question: Should you always fill your gas tank full rather than adding just a little each time we visit the pump?
There are a few angles to look at this from. The first is, what is the benifit to filling your gas tank full every time you go to the pumps? And the second is, of course what are the cons.
Pro: Less Frequent Trips to the Gas Station
The fact is, if you fill your tank only half full every time you visit the gas station, you're giong to have to make twice as many trips to the gas station as the next guy, who fills it up every time. That's twice as many kilometres, twice as many starts and stops and twice as much time idling waiting for the pump. Over the course of a year, this can really add up. This also means that you spend twice as much time travelling to the gas station.
Pro: Less Chance for Condensation in Your Tank
In Canada it can get pretty chilly in winter, and with this chill there is more chance for water condensation in your gas tank and fuel lines. As you run your vehicle the gas is heated up and when you turn it off it cools allowing condesation to take place. You can't stop condesation from happening completely, but if your tank is full there is far less room for this condensation to form, meaning that you will have less in your tank and fuel lines.
Con: A Full Tank Weighs More and Causes your Car to Work Harder
Some say that since a half a tank weighs less, it takes less fuel to drive around town on it. This may be true to a point, but the savings are insignificant at this level. Your gas tank, when full, accounts for less than 5% of your car's total weight (that's about 120 pounds). Reducing the weight of your car by 2.5% (by only filling your tank half full) would not have a noticible effect on your fuel consumption.
So weighing the results, it looks like there isn't a huge difference, but I think the votes are in favour of true on this one.