F Y I on Fuel

[ASmartMan]

Hey All

I pasted this from an e-mail someone sent me, I edited out parts of it because some of this e-mail was political in nature.

BUT most things said do make some sense, now exactly how MUCH of a difference (in % saved) is debatable, but I still thought it was worthy of sharing.




TIPS ON PUMPING GAS

I don't know what you guys are paying for gasoline.... but here in California we are also paying higher, up to $3.50 per gallon. But 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 Sa n 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 afterno on or in the evening....your gallon is not exactly a gallon. In the petroleum business, the specific gravity and the te mperature of the gasoline, diesel and jet f uel, 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. 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 & nbsp;pumping on the fast rate, some other liquid that goes to your tank becomes vapor. Those vapors are being
sucked up and back in to 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 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 the evaporation. Unlike service stations, here where I work, every truck that we load is temperature compensated so tha t every gallon i s 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 f the dirt that
normally settles on the bottom. Hope this will help you get the most value for your money.




ASM

[jwight]

ASM, some see the tank as half full, while others see it as half empty!

[rgaus]

Thanks, ASM. Good advice. For a "little" bit of free gas, try elevating a hose that has a "loop" in it. In other words, some hoses come directly down from the top of the pump and extend to your vehicle. Some hoses however, are longer and have a loop at the bottom. By lifting the upper end of the hose and removing the loop after your "fill", the extra fuel in that loop will drain into your tank for free! Hmm. Wonder if you could just go around to all the other pumps and drain those as well....
Ron Gaus, asmartcar.com

[Old smart]

The coefficient of expansion of gasoline is 0.00069 per degree F either side of 60F (the international standard temperature for petroleum calculations). Deep ground temperature where a gas station's storage tanks are located is prettly consistantly 55F in most parts of the country/world. If ten US gallons of gas were drawn out at 55F and allowed to heat up to 75F, the expansion would amount to just over one US liquid pint, though the weight (mass) would remain the same. The car's ECU meters air and fuel by mass not volume, so it would negate the expansion - in warm temperatures, fluffier air and fluffier gas to go with it. And a little less power because the swept volume of the intake stroke doesn't change.

[jwight]

Is the point of the post that since the meters on the pump don't compensate for temperature (or expansion), the volume of gas going into the tank may be less than 1 gallon, even though the pump shows 1 gallon?

[SmartAzz]

http://www.consumeraffairs.com/news0.../hot_fuel.html

[jwight]

Bookmarked that site! Great article.

[SmartAzz]

Glad you like it Consumer Affairs is a great resource and worth checking out sometimes, they even post auto recalls and related things.

[Fredvon4]

The originator is in the end of the game where millions of gallons per day are transfered some way, and the bottom line significance is real and calculated.

Most states have a division that certifies that the price per unit is accurate at the pump but not necessarily the unit per unit indication...depends on the state board of weights and measures

In the Army, the expansion and evaporation are real and costly factors we pay attention to. I hate to say how many times one of my fuel handlers would go to the tank farm with the aircraft refueling tanker (5000 gallons) and pump too much into the tank on a cool morning... not expecting to do the refueling exercise until late afternoon.

The Texas sun heats the tank to the point where the expanding fuel is peeing all over mother earth... and trust me, we have more problems then just the loss of an expensive fuel... now we have to clean up the spill and get the eco folks to certify the clean up.

Back to gas stations and car use; Our fuel use if of such small volume that over the life time of the car if all the factors are on the very extreme (out of calibration meters and highest expansion ratios) I bet there is only a two or three gallon variance from absolute reality

100,000 Miles @40mpg avg = 2500 gallons in 5~7 years
250,000 miles @40mpg avg = 6250 gallons in about 9~14 years

0.01% = 0.25 or 0.625
0.10% = 2.5 or 6.25
0.25% = 6.25 or 15.625
0.5% = 12.5 or 31.35
1% = 25 or 62.5

So with the coefficient of expansion of gasoline is 0.00069 per degree F I suspect the error may be more in the 0.01%~0.10% range vs the 1% range for the life of the vehicle...and thus not worthy of more more then an interesting factoid...certainly not worth changing any refueling habit in hopes of saving a few pennies (relatively speaking)

[SmartAzz]

Originally Posted by Fredvon4

...certainly not worth changing any refueling habit in hopes of saving a few pennies (relatively speaking)

Welp, as someone who has another vehicle that makes, ahem, less then 40mpg I'll make the effort when I can to get the chillier petrol vs the hot fuel - might as well IMHO, why give them any miniscule advantage when ripping us off