Why It Is Best to Fill Your Gas Tank After 6 PM

With the high gasoline prices seen in the last several years, many people are looking for tips on getting as much as possible out of every gallon of gas purchased. Recent reports have highlighted that pumping gas during cooler times of the day, such as evening or early morning, may actually give the consumer more fuel energy per gallon of gas.

Expansion of Gasoline

  • As temperature increases, gasoline will expand, thereby increasing its volume. The amount of energy in gasoline is related to weight, however, and not volume. This means that fuel pumped in areas with hotter temperatures will contain less energy than fuel pumped in regions with lower temperatures.

Hot Fuel Premium

  • A government study conducted in the summer of 2007 analyzed how much consumers spent on gasoline affected by temperature. This research concluded that consumers purchased over 513 million gallons of gasoline that were attributed to the thermal expansion of gasoline. This equated to a "hot fuel premium" of about 1.5 billion dollars during the summer of 2007.

Best Time of Day

  • There are conflicting perspectives on whether one should pump gas early in the morning or late at night. The storage tanks for gasoline are underground, and many argue that the best time to purchase gasoline is in the morning because the gasoline cools down the most during the night. However, pumping at night (after 6 p.m., for example) would still be more effective than pumping gasoline during the middle of the day. The overlying concept is that the colder the temperature, the denser the gas will be. This will mean that more gas will be pumped into your tank at the gas station.

Myth?

  • There is also the belief that the time of day gasoline is pumped does not dramatically affect the price paid. Gasoline expands approximately 0.069 percent for each Fahrenheit degree. Some believe that this does not make a big difference overall. However, AAA Arizona spokeswoman, Linda Gorman, believes that pumping gas first thing in the morning will get consumers the best deal at the gas pump. Many consumers believe that every little bit of money saved is helpful, especially in today's economy.

Other Advice

  • There are many other tips and techniques available for saving money on gasoline. One is to ensure that your car is properly maintained. Cleaning air filters and keeping tires at the correct tire pressure will also help you get more money for every gallon of gasoline purchased. Your local mechanic or auto retailer will be able to offer more advice on what types of other affordable services are available to maximize gasoline efficiency.