Reader Amanda passed on this information on saving money at the gas pump, and I thought I would share it with all of you. I did check it out on snopes.com to verify that it is legitimatem and they have a mixed review. The article is quite lengthy and a lot of their complaints about it is that it takes more time and is inconvenient. But, that's what a lot of people say about couponing and I obviously see the value in clipping/using coupons! So, here are the tips:
Only buy or fill up your car or truck in the early morning when the ground temperature is still cold. Remember that all service stations have their storage tanks buried below ground. The colder the ground the more dense the gasoline, when it gets warmer gasoline expands, so buying in the afternoon or in the evening....your gallon is not exactly a gallon. In the petroleum business, the specific gravity and the temperature of the gasoline, diesel and jet fuel, ethanol and other petroleum products plays an important role. A 1-degree rise in temperature is a big deal for this business. But the service stations do not have temperature compensation at the pumps.
*Snopes concedes that doing this could save you about $31/year (if you're purchasing 15 gallons of fuel each week at $4/gallon.
When you're filling up do not squeeze the trigger of the nozzle to a fast mode If you look you will see that the trigger has three (3) stages: low, middle, and high. You should be pumping on low mode, thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some of the liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money.
*Snopes agrees that pumping slower does reduce the amount of vapors, but their main contention is once again - the time issue.
One of the most important tips is to fill up when your gas tank is HALF FULL. The reason for this is the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine. Gasoline storage tanks have an internal floating roof. This roof serves as zero clearance between the gas and the atmosphere, so it minimizes the evaporation.
*Snopes says that doing this will mean you fill up your tank twice as often. At 8 minutes per trip to the station (including driving there, paying, filling up, and getting back on the road), this will take 7 hours/year to achieve a roughly $62/year savings.
Another reminder, if there is a gasoline truck pumping into the storage tanks when you stop to buy gas, DO NOT fill up; most likely the gasoline is being stirred up as the gas is being delivered, and you might pick up some of the dirt that normally settles on the bottom.
*Snopes agrees that dirt and sludge do get stirred up when tanker is refilling, but gas stations are required to have filters and our cars also have fuel filters.
So, my personal opinion about all of this is - why not give it a try? Gasoline is now $3.60/gallon here in Charlotte (and that's for the cheapest stuff) and I just about cry every time I fill-up. Automobiles definitely run better (and it's just safer) to keep a gas tank more full. You've got to buy gas at some point, why not the morning? And are we in such a rush in our lives that we can't pump the gas on the low setting? Even if it's not saving us a dime, isn't it better to not release all those vapors for us to breath in while standing there pumping the gas? Doing these little tiny things saves you at the bare minimum about $100/year. I don't know about you - but I could find a way to spend an extra $100! :)