| tips on pumping gas
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| gotMDX |
I'd like to share this info.......a friend emailed this to me....
TIPS ON PUMPING GAS--GOOD INFO
I don't know what you are paying for gasoline....Here in
California we are pay, up to $3.50 per gallon. My line of work is in petroleum, 31 years now, so here are some tricks to get your money's worth for every gallon.
at 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 diesel the next day jet fuel, and gasoline, regular and premium grades. We have 34-storage tanks with a total capacity of 16,800,000gallons.
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 theafternoon or in the evening....your gallon is not exactly a gallon. In the petroleum business, the specific gravity and the temperature of 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 last mode. If you look you will see that the trigger has three (3) stages: low, middle, and high. In slow mode you should be pumping on low speed, 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 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 for your money.
One of the most important tips is to fill up when your gas tank is HALF FULL or HALF EMPTY. 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 evaporation. Unlike service stations, where I work, every truck 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. |
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| laborlitigator |
| Excellent tips. Thank you! |
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| hammermdx |
| I never fill my vehicles if there is a delivery being made, you are right about that. Life is too short to worry about the other stuff......:4: |
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| G. COLTON |
The part about the delivery truck possible stirring up trash in the storage tank has some merit.
Otherwise, if you follow this advise for the next ten years you may save $1.00.
GAS PUMPING TIPS
g |
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| highcountrymdx |
You gotta wonder if a lot of this is just so much 'urban myths'. For example, just how much does the temperature of fuel in a tank buried 10 feet below the surface vary from night to day. I'm betting not much if at all.
I've often heard the one about stirring up the dirt in the underground tank. Is it really true? And, aren't there filters located somewhere in the filling station pumping system?
Now, let's look at the claimed advantages of keeping the vehicle tank full to minimize fuel tank vapors. All modern emission control systems include a canister of activated carbon that removes these vapors from the vehicle fuel tank and return them to the engine to be burned. The vehicle fuel tank systems are a closed system, specifically designed to prevent vapors from escaping.
Finally, about fill rates. That myth has been around forever. Sounds like it makes good sense, as all good rumors do. But has anyone ever tested the difference in gallons billed and gallons delivered due to vapors created as a result of gasoline delivery rates? It's probably so small as to be virtually non existent. Now, fill rates for transporters at the fuel farm could be a different story. Maybe. |
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| gotMDX |
[QUOTE]Originally posted by hammermdx
I never fill my vehicles if there is a delivery being made, you are right about that. Life is too short to worry about the other stuff......:4: [/QUOTE
I, too, will surely not fill mine when there's a delivery truck around! I'm trying(again?) to stay fit and filling up the X will be another early morning errand for me before hitting the gym. I'll try the nozzle thingy and see if it helps at all. It might take a couple of months to see if I'm getting more for my gas $$$. |
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| JeffK |
Dear HighCountryMDX:
Thank you!
Sanity reigns!
IMHO, this is nothing more than Urban myths and as G.Colton correctly points out, even if true, your savings may be $1.00 over 10 years!
JeffK |
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| jhue |
From what I've found via a little Googling:
The thermal coefficient of expansion for gasoline is .00095 per degree C. Round it up and say .001, or 1/10th of 1%. The remaining question is, what is the temperature difference between night and day of the gasoline passing through the pump when the volume is measured? I don't know the answer to this, though I do know it's nowhere near the difference in air temperature between night and day. I'm going to guess that it's no more than 1/3rd the difference in air temperature, so if the difference in air temperature is 30 degrees F (78-108 typical daily range in desert southwest in summer), the difference in gasoline temperature is maybe around 10 degrees F or 6 degrees C. So if you're buying $200 worth of gas a month, that 10 degree F difference is worth about $1.20, or about 100x G. Colton's uneducated guess.
The following link points out that most gas pumps are calibrated to 60 degrees F, while the average temperature of gas pumped in California is about 75 degrees F, resulting in about a 1% overcharge. Note that this has nothing to do with temperature differences between night and day, it has to do with the difference between the pump calibration temperature and the average gasoline temperature.
http://www.oilwatchdog.org/articles/?storyId=5821 |
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| JeffK |
Thanks for the post. I am sure mathematics are correct, however:
Some of you may have a wine cellar or if not then you know of someone who does.
The purpose of the wine cellar is to keep wine at a fairly constant temperature.
Remember, this is thousands of gallons of gas in an underground sealed tank. I suggest that the difference in temperature between night and day is minimal at best and probably not measurable at all during a 12 hour period. Week to week, maybe, month to month yes.
The biggest difference will be seasonal: Warmer in summer and cooler in winter.
JeffK |
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| psu1994ca |
I agree with the last post. That list of things that you can do to save money is really a bunch of crap. In theory they may be true... but as was mentioned before, the Tanks are below the ground so they stay at a constant temperature. The fuel trucks can stir up sediment, but they lines have filters. They will not pump if the filters clog.
My wife worked for BP for 7 years and now Chevron. We joke about comments like this all the time.
The only real tip is do not top off your tank because the gas that will not go down into the tank is sucked back up in the hose with the vapors.
You can google this and find a lot of Blogs where they talk about why this e-mail (that has been going around for a long time) is not all based on fact. My Favorite line is:
I've been in petroleum pipeline business for about 31 years, currently working for the Kinder-Morgan Pipeline here in San Jose, CA.
My Aunt used to work for AT & T for 27 years, but she still didn't know squat about how a telephone worked
If you buy into this... I will forward you the e-mail about how the GAS OUT (no one gets gas on Tuesdays) is going to work! |
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| jhue |
It's not clear to me where the volume of gasoline is measured when you're pumping gas. If it is measured underground, or near the storage tank, then I agree with you, the temperature is not going to vary much. But if the measuring is done closer to, or in the pump as I suspect it is, there is more opportunity for the fuel to rise in temperature as it moves from the underground tank to the pump.
I guess it wouldn't be that hard to just stick an instant read thermometer in the fuel stream as you're pumping and put this argument to rest once and for all. |
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| psu1994ca |
quote:
Originally posted by jhue
It's not clear to me where the volume of gasoline is measured when you're pumping gas. If it is measured underground, or near the storage tank, then I agree with you, the temperature is not going to vary much. But if the measuring is done closer to, or in the pump as I suspect it is, there is more opportunity for the fuel to rise in temperature as it moves from the underground tank to the pump.
I guess it wouldn't be that hard to just stick an instant read thermometer in the fuel stream as you're pumping and put this argument to rest once and for all.
Lets say it is measured at the nozzle... and it is 100 degrees out... if the gas was cool when it left the tank and now it is in a sealed pump.... where would it expand to? The pumps have to be designed to not leak... they do not have a secondary storage location and and I am sure they do not allow fuel to flow backwards...
even if it could expand under the conditions... how much could it effect your 17 gallon pump? Keep in mind the pump would only hold a few gallons MAX for safety. |
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