There is a chain post making the rounds in my social networks. It asserts that gasoline vapors can affect how much fuel you actually get. To minimize the amount of vapor passed through the nozzle/meter you should:
- Pump gas at the slow setting
- Pump gas when the cars tank is half full or more
- Not pump gas when the delivery truck is refilling the big station tanks
The post reeks of a chain letter and unverified science.
Is there any truth to the premise that gasoline vapors impact the metering of fuel? In other words will a gas pump measure liquid fuel volume or any fluid fuel volume?
If the premise is true, do the 3 behaviors actually reduce fuel vapors?
How much does gasoline expand and contract when temperatures change?
TIPS ON PUMPING GAS I don't know what you guys are paying for gasoline.... but here in California we are paying up to $3.75 to $4.10 per gallon.
My line of work is in petroleum for about 31 years now, so here are some tricks to get more of your money's worth for every gallon:
Here at the Kinder Morgan Pipeline where I work in San Jose , CA we deliver about 4 million gallons in a 24-hour period thru the pipeline.. One day is diesel the next day is jet fuel, and gasoline, regular and premium grades. We have 34-storage tanks here with a total capacity of 16,800,000 gallons.
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.
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.
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. Unlike service stations, here where I work, every truck that we load is temperature compensated so that every gallon is actually the exact amount.
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.
To have an impact, we need to reach literally millions of gas buyers. It's really simple to do. I'm sending this note to about thirty people. If each of you send it to at least ten more (30 x 10 = 300)...and those 300 send it to at least ten more (300 x 10 = 3,000) and so on, by the time the message reaches the sixth generation of people, we will have reached over THREE MILLION consumers !!!!!!! If those three million get excited and pass this on to ten friends each, then 30 million people will have been contacted! If It goes one level further, you guessed it..... THREE HUNDRED MILLION PEOPLE!!! Again, all you have to do is send this to 10 people. How long would it take?