Tricks to get more of your money's worth for every gallon...

[sirwilliam]

Not sure if this was posted already. This was sent to me today and is very interesting as well as logically feasible:

I don't know what you guys are paying for gasoline.... 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 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. 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 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 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 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.

Hope this will help you get the most value for your money.

[Phibs]

Step 2:

Don't buy an STI, oh wait.... wrong forum!

[Bluestreak2006]

^Hah... Oh what I really dont get that great mileage. Crap

[WRXWagon2112]

Has anyone vetted this through Snopes.com yet?

--Alan

[Sabre]

Nope... but I was told by someone that adding a little (as in a cap ful) of acetone... been meaning to bring that up in a separate thread actually.

Looks like according to Wikipedia that it (Acetone) was debunked by Mythbusters.

[bbyevochick]

interesting

[Mr Kleen]

Has anyone vetted this through Snopes.com yet?

--Alan

Snopes says: Research In Progress

[zaxrex]

If any of you have worked in construction, you will know that you can find a nice cold place if you dig 5 inches of soil below the surface. Even less if you are going through concrete. Hell, anybody who has ever tried just moving paving stones in a walkway can remember how the ground is much cooler. That is all during the day. At night do the same thing, and the freshly exposed ground is warmer than the ambient temperature

Where are these underground tanks? Oh wait, thats right. UNDERGROUND. The daily temperature 10 feet underground changes so little, that your driving style will have more effect on what you get from your tank than the time of day you fill, up.

Coefficient of volumetric thermal expansion for gasoline is 0.000950/degree Celsius, water BTW is 4 times less at 0.000210, but still not buckets of difference.
Say you have a small rural station with a 500 gal underground tank with the EPA mandated triple barrier envelope.

Scratch that, let’s go worst case scenario. That tank is above ground with no insulation and immediately stays the same temperature as the air and you had a 30 degree F temp swing over night. To make it easy, call that difference 17 deg C. The theoretical maximum volume difference in that tank would be 8 gallons. 1.6% difference. You can find more variation than that in the prices at different stations of the same brand. And that is the worst case, and that is a lot when your buddy is talking about the 16,800,000 gallon tank farms. For them that would be a worst case scenario of 268800 gallons -- a crap-load of course. But then again, diesel, JP8, jet-A, and kerosene (the other petroleum products he deals with) have much lower expansion coefficients.

I would be absolutely shocked if the maximum liquid temperature difference over a three day period for a 500 gal underground tank was more than 3 deg C. That is 1/6 of the worst case scenario, 0.03% difference.

Take the extra time in the morning. Check your tire pressure and tap out your air filter. You just saved yourself a trip to the fill-up station on your way to work. And since you just inspected the condition of your tires while you were down there checking the pressure, you are probably safer this way as well.

[Phibs]

^^^ +1, well said zak!

[chicken n waffles]

dude, i was totally just going to say everything zak just said.

[avriette]

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.

My god! Somebody should invent a filter for fuel lines!! They'd be F-in rich!