Time and Speed Matter

You fill up before work, your husband fills up after work. No difference, right? Actually you will see a visible difference if you pump your gas the correct way.

When you pump gas, the meter measures the gas by the volume you are pumping. The volume of liquid measured by the pump cannot be altered, but the density of the liquid can.

If you pump gas in the early morning, when the temperature is still cool, the gas that has sat in the tank overnight will have cooled and become more dense. Therefore when you pump that more dense gas, you will actually be getting more for your money.

Pumps in the United States are set to measure one gallon of gasoline at 60 degrees F. So if you are pumping gas at temperatures any higher than that, you are losing money. If you pump more dense gas, when it expands in your tank, you will actually have more volume than with less dense fuel.

Another way to pinch pennys at the pump is to pump on the lowest speed setting. When you pump gas at the fastest speed, it stirs up the gasoline and causes some of it to turn to vapor. Most of that vapor produced dissipates and never makes it into your gas tank.

Even though it may be a hassle, just remember: pump your gas in the morning when it is cool outside, and pump it slow, so you maximixe the amount of liquid going into your tank and minimize the amount of vapor you lose.