Are You Getting Ripped Off by 'Hot Gas' ??

[kch88]

Hmm. Good to know. I was just going off what I'd heard from people. I also used to wonder why older gas pumps only had two "odometer" type things measuring off quantity, when there were actually three types of gas. How does that work?

[Krazy Hawaiian]

They simply draw from the different brands tank. Heck Sunoco had at least 6 different types at one point all from one pump. For a long time Sunoco was some of the highest octane gas you could buy in the 70's.

Then came Unions purple race gas.... I ran it in my RD 400 2 stroke when I could get it. That was some really nasty gas.... almost 5 bucks a gallon and came in 55 gallon drums. Very few stations had it. Only one here did, Niu Valley 76 a mile from my house. The owner was a big drag racer.

[robert_s_hunter]

Originally Posted by kch88

Hmm. Good to know. I was just going off what I'd heard from people. I also used to wonder why older gas pumps only had two "odometer" type things measuring off quantity, when there were actually three types of gas. How does that work?

Well, the last mechanical pump I saw only dispensed one grade per pump. But that's been quite some time ago. I suspect that the pump you recall was actually an electronic pump that simply indicated what the flow was for the grade that was selected.

Modern pumps with one hose for all grades of gasoline are another of those things that seem to perplex people. When you select the grade of fuel you want, a valve is opened for the chosen supply-line and the fuel flows from that supply into the common delivery-line. While there may be some fuel from the previous transaction in the hose, it isn't of a significant enough volume to create an issue. In fact, the volume is far less than you might imagine, as the hose you see is actually TWO hoses. There is both a delivery-line and a return-line, the return-line venting the vapors from your fuel-tank for emissions-control purposes.

[Stangman33]

Originally Posted by robert_s_hunter

Two different issues..... I pointed out the F1 practice of freezing fuel to illustrate that temperature does indeed influence it's volume.

Currently, fuel is sold here by a simple measurement of it's absolute volume. As fuel expands when it's temperature rises, and contracts as it cools, this means that you are getting less energy (BTU's) when the fuel is "hot" than when it is "cold". So, when you buy fuel when it's reached it's hottest point during the day, you get fewer BTU's per dollar and vice versa. When a pump compensates for this thermal expansion, it adjusts the display to reflect an "equivalent" to the fuel's volume at a specific temperature. Then you would get a "gallon" of more than an absolute gallon, when the fuel is "hot", and less when the fuel is "cold". Thus, you would get EXACTLY what you've paid for..... Which the Europeans, and bulk fuel purchasers, already do.

On a modern fuel-injected vehicle, an engine's ECU adjusts it's fueling based on this principle. A simpler example would be the difference in the carb jetting between two otherwise identical engines, one running on gasoline (high BTU per volume) and one running on alcohol (low BTU per volume). The gas engine
would run much smaller jets due to the higher BTU content, while the alcohol engine would be jetted to flow a significantly higher volume of fuel, in order to provide each engine with the necessary BTU for proper operation.

The practice of freezing fuel in F1 was used to allow teams to put, what would have been at ambient temperature, more than 150L of fuel into a 150L tank. The fuel had to be heated before it was introduced into the engine in order to achieve optimum fuel atomization. A fuel at such a low temperature would actually cause a reduction in power.

Ok I thought we might have been on two different issues. Can you give the densities of gasoline at different temperatures? I've looked online for about an hour with no luck.

[robert_s_hunter]

Originally Posted by Stangman33

Ok I thought we might have been on two different issues. Can you give the densities of gasoline at different temperatures? I've looked online for about an hour with no luck.

Fuel densities may vary from grade to grade, refiner to refiner, and even locale to locale, due to differences in formulations. This is why the FIA and FIM have very specific standards for what they will allow a refiner to provide competitors as a "gasoline" for use in competition. You can get an insight into just how wildly things can vary, and how complicated it all is, by going to http://www.fim.ch/EN/rules/Sportifs/...GP_tech_en.pdf , and checking out pages 54-60. SEVEN pages, out of a total of just twenty pages of MotoGP regulations, just to address the fuel in a MotoGP bike's tank!!!

Also, you might find http://en.wikipedia.org/wiki/Gasoline an interesting bit of "light" reading. There is also a pretty good list of references linked there, that you can dig into if it strikes your fancy..... This would also be good reading material for those who don't understand why using a gasoline with an octane rating higher than absolutely necessary will actually cause a LOSS OF POWER.

[modette]

Originally Posted by kch88

Gas stations generally have 3 tanks. One high grade, one low grade, and one diesel. With the high grade and low grade together they mix them in certain quantities to get whatever octane rating they want.

Yes, it is acalled a "blender valve" in the pump. Older places used to have to have a tank for each grade...this little invention helped a lot. However you can adjust the valve to give more regular then Premium...hehehe Been known to be done.

A lot of stations (depends on your state) will use one Diesel tank (assuming they sell Diesel), and One big tank that will be divided up into compartments. Oh, I forgot about the K1 tank, stations will have this too, most will switch this tank from Race Gas to Kerosene as the weather changes...never buy Race Gas from these places). This is so they get around the tax per tank they have, because technically it is one tank that is split into many (usually 2, but can be more).

Also the tanks are double walled to provent leakage nowadays. They last a lot longer then 5-10 years.

As the fuel prices go up, that is more money the station owner has to put up front to get a product that may or maynot sell, and who knows if it will be a gain or a loss. If the owner had to buy 10,000 gallons of Ragular ($30,000 up front) $2.50 + .40 for tax = $3.00 and then they turn around and charge say $3.15 that equals $31,500...wow a whoppin $1,500 made on a perfect day.

But what if gas prices go down and the station down the street is now at $2.80 a gallon? You will have to bring yours down close to that if not the same to get customers to come in. So lets say $2.90 in hopes your customers won't drive the extra block (int he real world they do). So that is $29,000 a loss of $1,000. In the real world the loss could be greater or be a mix of gain and loss, meaning you make $200 per 10,000 Gallons.

This is why the store front is such a major player for the gas station in todays world. It helps off set the loss from gas sales, and turnes it into more gains then losses. Having a McDonalds that pays RENT is the ideal station...you always have money coming in from them being there. Also as they always stay open late, it is extra security so you are not robbed either (keeps the place busy with people).

Most gas station owners are not becoming rich from selling gas...sorry to say. Most make an honest living and maybe make big bucks if they start to own more then one or get lucky and an area becomes a major intersection. Between the $800K for most stations to the $5 Million for the big interstate ones...I would hate to have that payment, plus the upfront cost of the fuel, food, and other shit you buy, plus the property tax, the fuel tax, and the tank tax, not to mention the hassle with the EPA and test holes, and monitoring equipment. I'm happy to pay .15 cents .25 mark up on the gas.

[modette]

There is also triple-wall tanks too now.

Multi Compartment Above-Ground tank:
http://www.convault.com/drawings/OMfigs/fig3.jpg

Some good drawings and tells you how the tank needs to be installed:
http://www.xerxescorp.com/singlewall/pdf/imog02.pdf

Gas Prices and how they work:
http://www.howstuffworks.com/gas-price.htm

[robert_s_hunter]

Modette is right, the big money maker is the convenience store. Typical profit on gasoline sales is a matter of pennies.....

Our government entities make far more money from a gallon of fuel, than those big evil oil companies!

[the PNASTY]

Originally Posted by kch88

Gas stations generally have 3 tanks. One high grade, one low grade, and one diesel. With the high grade and low grade together they mix them in certain quantities to get whatever octane rating they want.

That's how the one I used to work at was set up.

[WesR6]

Modette is correct. I work in the petroleum industry and have been for 4yrs. We build/service Gas Stations in Michigan, Indiana, Ohio and Kentucky. In Michigan, most tanks are burried at least 6 feet below ground level. Almost all of the tanks installed these days are fiberglasx reinforced tanks. Double walled to prevent leaks. Inner tank holds the fuel, then you have about a 1 inch air gap all the way around the tank and then the outer firberglass layer. This also is a minimal form of insulation.

I'm not sure about the rest of the country but here in Michigan you are not likely to find gas above 60 degrees, even in the heat of summer due to the burriel depths and type of tanks.

To touch on a few points Krazy mentioned. As modette has stated, most dispensers around the country are now blenders. We have a sunoco that has 6 grades of gas but only two products on site. 93 octane Premium and 87 octane Regular. All 6 grades are a combination of the two products mixed at different ratios. 89 octane is generally 60/40 of reg/prem. If you see a site with alot of tanks, it may be an old 1 tank per grade site that has been converted to blenders. In this case they will make two tanks regular and two tanks premium that are siphoned together.

Lately we've been installing one or two tanks per site depending one what they need. If they are just running Regular/Premium/Diesel they may get away with one really large tank that has been compartmented, or one large and one small for diesel.

I don't really see this as a big problem for the reasons modette has already stated. They may make a little bit of money some days and then loose the next. The gas is there to get you onto their property with the hopes that you will come inside and buy something. CRINDS/DCRs (Credit at the dispensers) has changed the way they do buisness due to the fact that they fewer customers comeing inside.

Michigan watchs it's gas stations closely. They are all subject to random tests by DEQ and also Dept. of Agraculture. They will come around checking calibration and once that is complete they will take samples of the fuel and send it to their lab to be tested to make sure that it's actually what it is supposed to be. Not to mention the different service companys that also go around checking these same things through out the year.

Personally this temp thing may be an issue in some parts of the country but even then I don't see it being THAT big of an issue. I think someone is wanting to get rich quick/make a name for themselves.

-Wes

[Anthonyd5189]

I thought liquids cant be compressed, so how would temp effect the volume of gas your receiving.

Dont get me wrong, I get my gas at the coolest part of the day when I can because I have heard this before...but someone brought that up to my attention and I don't have an answer for it.

So if one of you guys could draw it out for me it would be much appreciated.

[bassholic]

i am not sure this should really matter, if it cost me $100 a yr so be it.

[robert_s_hunter]

Originally Posted by Anthonyd5189

I thought liquids cant be compressed, so how would temp effect the volume of gas your receiving.

Dont get me wrong, I get my gas at the coolest part of the day when I can because I have heard this before...but someone brought that up to my attention and I don't have an answer for it.

So if one of you guys could draw it out for me it would be much appreciated.

While a liquid can't be compressed (think of a "hydrauliced" cylinder), a liquid does indeed change in volume due to temperature variance. While water is unique, in that it's volume shift is inverse of that of other liquids, you can prove the point yourself. Take a can of your preferred beverage, and notice the sloshing sound due to the empty space above the liquid, and now place said can in your freezer overnight. In the morning, tell me what you discover about the thermal effect on the volume of a liquid.....

[robert_s_hunter]

Originally Posted by bassholic

i am not sure this should really matter, if it cost me $100 a yr so be it.

I'm in the transport business and believe me, it matters. Ultimately, you are the one paying my freight bill, with the cost of my service included in the price of every single thing you buy.

My trucks are currently equiped with 300gal tanks, and at the current national average price for diesel fuel of $2.853, it costs me $855.90 every time they fill up. Running an average of about 240K miles annually, and with fuel-economy averaging about 6.5mpg, that makes my fuel bill MORE THAN $105K PER TRUCK. This doesn't even take into account the fuel used to operate the temperature-control units on my trailers!!!

I CHALLENGE ANYONE TO CONTEND THAT EVEN A 1%-2% SHIFT ISN'T SIGNIFICANT AT THIS RATE. REMEMBER, YOU AS THE CONSUMER ARE HAVING TO PAY FOR MY INCREASED COSTS DUE TO MY NOT RECEIVING FULL VALUE AT THE PUMP.....

[Krazy Hawaiian]

^^^ as I said many posts ago.... even the smallest amount of expansion may seem insignificant on a large scale it runs into huge amounts....



and for the un believers in "expansion" and liquids, please take a sealed unopened soda can put it on your stove with the burner turned up high and watch the resultant expansion do its biz and be prepared to be covered with scalding soda..... cans of beans in the campfire also work


On second thought don't do that although the beans are a great prank