Costco Might Fix Hot Fuel Ripoff
Vermonters get a better deal on gas than Texans. Fuel expands in the heat and shrinks in the cold, so 5 gallons of "hot fuel" won't get your car as far as 5 gallons of regular. Oilmen know this, and that's why at various points in the supply chain volume gets adjusted for the industry standard temperature of 60° F. The retail pump isn't one of them. That might start to change if a proposed class-action lawsuit settlement with Costco as a defendant goes through. Under the terms, Costco would fix its pumps in the bottom half of the country so that they dispense fuel at 60° F. If it goes through, it would be a precedent-setting consumer victory. After all, you want a Tiger in your tank, not a Heat Miser, don't you?
Costco offer would fix hot fuel [Kansas City Star] (Photo: whatatravisty)
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Didn't someone look into this a while back and determine that because the tanks were stored underground the temperature is pretty constant all over?
I think so. I remember someone doing the math with the expansion ratio pertaining to heat and it came out to be like 3 cents more expensive for a 10 gallon tank of gas when pumping it at 90 degrees compared to 60 degrees.
@Stanwell: Does the ground stay at a constant temperature of 60°F? I'm no expert but I would assume that in the summer when the temperature is consistently 100°F, the temperature of the gas is probably a lot higher than 60°F.
Also, when the gas is transported in a metal container to the station, the temperature of the gas is probably a lot closer to the outside temperature.
Gasoline expands by 1% for every 10C or 18F. Given the price variability within a single city, this seems like a non-issue.
@Stanwell: Consumer Reports, of all people, debunked the myth that ambient temperature affected the amount of gas that flowed from the pump. In short, the environmental temperature had no effect whatsoever on how much gas one actually received (since the flow temperature always stayed fairly constant).
The article makes a point of this as well.
So hot fuel is not like summer and winter air?
I was somehow under the impression-- very possibly mistaken-- that the ground below a certain depth maintained a fairly constant temperature through most of the US, and that the tanks at most gas stations are deep enough that they aren't affected much by the temperature above ground. The temperature of the gas as it goes INTO the tank is a different matter, of course...
This only holds true in the storage tank underground only. A tank holding 1000gal at 60F will hold 1028.8gal at 90F (Change in Volume = .00096 * Initial Volume * Change in Temperature). However, this is a rare occasion as most tanks are so far underground they experience at most a 5 degree fluctuation throughout a specific season. In effect, temperature has no effect at the pump; as far as your wallet is concerned anyway.
While it is true that gas does expand and contract with temperature, 99% of all gas pumps (by law) already account for this. They do this because they measure how much is pumped not with a volumetric flow meter, but with a mass flow meter. The difference is that a volumetric flow meter only measures a specific size of fluid, meaning that if the gas has expanded, it will measure higher than before. A mass flow meter measures the mass contained in the fluid, which is independent of the fluid's density (thus volume) at that specific time. With a mass flow meter, it should dispense the same quantity of gas at 1000F as it would at -20F.
The only way that I can see this holding any ground is if there are pumps still measuring with volume flow meters, or if the pumps have been tampered with.
@ecwis: At the depth that these tanks are under ground it would be pretty close to a constant 60°F.
The main temp change would probably occur in the trucks hauling it to the station, but even then it is a large volume of liquid so it would take quite a while to raise the temperature even a few degrees. Then this slightly warmer gas is mixed in with some ground temperature gas and cools down a bit. As it sits under ground it goes back down closer to the 60 or whatever the ground temperature is.
Even the busiest stations only get one tanker full of gas every day or 2 so it isn't like gas is constantly being added at a warmer temperature.
Hold on, the pumps there don't adjust for temperature?
All the ones I've ever used explain they will adjust the volume you pay for to temperature match whatever the temperature should be (I can't remember what it is here, it isn't in Fahrenheit, of course).
If the pumps do that, you pay the same for the same fuel at any temperature.
@Phexerian: I actually performed this calculation last year and found it to be something along that order of magnitude.
Although, if one really cares that much about 3 cents...
@Stanwell: I work at a gas station in central Texas of all places and I don't really understand all of this. I am able to read the actual temperature of my tanks and get the current temp in about 5 seconds.
I had a customer that actually asked me about this and I printed out my current temp for him to see. It was about 97 degrees randomly one day and the temp for one tank was about 75 degrees F and the other tank was at 76 degrees F. That is only 15 degrees more than the industry standard.
Furthermore, this was only 30 minutes after we had a delivery of about 8 thousand gallons in our 12 thousand tank.
Doesn't seem like that big of a deal, the tanks are underground and isn't the ground temperature under ground about the same no mater the temperature outside?
The pumps at my costco in the chicago burbs have a little sticker on them that says they aren't temperature corrected.
@C.S.M. Technophile: Do you have a source for your contention that "99% of all gas pumps (by law) already account for this"? That would seem to conflict with the entire contents of the original article (linked above) and the lawsuite.
From my understanding, in the US, '99% of all pumps' do NOT account for this and there is no such law. Please prove us wrong by pointing at the law.
Since Costco had to be sued to get them to do this across 20+ states, i would imagine that you are completely wrong..
Now THAT would be awesome! I try to fill up first thing in the morning or late in the evening, especially down here in S. Central TX. That expanding gas is no joke in the heat we get here.
@benh57: My apologies. I intended to include that this was Colorado, and assumed that this applied most everywhere else. It was my understanding pumps that utilized volumetric flow meters were no longer in production, thus unlikely to still be widespread.
While I don't have the link where my figure (99%) was originally sourced, I personally received it at the last Society of Automotive Engineers meeting I attended back in March, and took it in blind faith.
So in order to compensate for the tiny percentage of difference in fuel volume, we're going to force Costco to pay lawyers millions of dollars and install millions more dollars in gas storage cooling units.
I'm sure the consumer will NEVER end up paying for any of that. This is clearly a fantastic idea.
@Frank Murphy: You didnt get winter air for your tires? I am supprised you were able to drive safely!
@supercereal:
I've read several reports that average losses due to nothing more than the pump dispensing AVERAGE amounts of gas... can be much higher than losses due to temperature. One driver can fill up getting up to 20% more gas while the next guy fills up getting 20% less at some stations. The temp is the same, the rate of flow is average only in the long run. While this is supposed to be regulated and consistently checked and adjusted, it can vary by a huge amount at some stations, and even at different pumps at one station.
Your best bet is to try to use different pumps often, because you don't know whether you're getting shorted every visit.
I consulted with a Canadian refiner/distributor for a few years and wanted to point out the pumps you mention in the story won't actually cool/heat fuel to 60F, they'll dispense VOLUME equivalent of that temperature.
It's been the law in Canada for many years. Yes, the temperature of underground gas tanks is pretty stable so the correction at the pump is small (but shame on Costco anyway.)
The real issue is the delivery of heating fuel. A delivery truck driving around all day in the baking sun. Wonder if anyone's checked whether those trucks are volume corrected??
yet ANOTHER reason why I LOVE Costco.
if only they sold the 97% fat-free Hebrew National hot dogs... (those are impossible to find in bulk!) but everything else associated with Costco is awesome.
@Andrew Farris: 20%?! So you're saying that someone getting 10 gallons of gas can actually get 12 gallons or 8 gallons of gas?
@Julius Seizure. Jim to my Peeps: But that is diesel, which has different properties than gas. Also, in all the trucks I have seen, the counter counts down from the initial fill in the morning, and the last person gets the last of the oil. My oil company likes to use my house as a "empty the truck" stop, so I routinely get receipts with the end reading of 000.00.
If I can get some people to quit repeating this myth, can the other gas stations take those stupid spam boxes off the pumps that tell you about all the "great deals inside"?
@supercereal: Even if it did fluctuate, it is not that much of a difference. You are talking like less than teaspoon worth in 50 gallons.
"Vermonters get a better deal on gas than Texans."
Average gas price in Vermont: $1.946/gallon
Average gas price in Texas: $1.810/gallon
This lawsuit is idiotic. Any differences are already built into the pricing. What's next "people who buy regular get a better deal than people who buy premium"?
@David Schwartz: "Any differences are already built into the pricing."
You really think that? Let me introduce you to something called "state and local taxes". Not to mention "proximity to refinery."
The lawsuit is, indeed, idiotic.
@cjdmi: Yep. It is pure bull. We are talking about a change of 0.5% per every 5° Centigrade or 9° Farenheit. The difference, then, between -40°F and 120°F (I think these are reasonable extremes between the coldest and warmest in the continental US) is going to be about 9%.
Seriously, though, how often are these -40° and +120° temperatures going to be encountered? With tanks generally being underground for myriad reasons, they just don't vary that much.
@Stanwell: The temperature underneath the ground is about 50F. No, this can vary due to the consistency of the soil, but I couldn't see it getting higher than 60F.
That doesn't mean that the gasoline will always match the soil temperature, but after a few hours it will probably be close. If you're really worried about it, buy your gas early in the morning, or you can ask for a gasoline temperature, like Nick Van Duyn suggested.
20%? Looking at standards, it's more like .4%
Per [www.consumerwatchdog.org] expansion is .069% per F.
Looking at it - they assume the gasoline is at 90F, which yields a 2.5% difference between it and 60F gasoline.
At $3.50/gallon, this makes a 'mere' 7 cents difference per gallon. In my experience, the difference between winter and summer gas is higher.
Personally, I think that 30 is assuming high, and the cost for retrofitting pumps is expensive, thus the end result to consumers for fixing this inequality would be higher gas prices even for temperature adjusted gallons.
@Stanwell: Having driven a refueling truck for several years, I can attest to two things:
A.) The liquid in a fuel truck tends to stay significantly cooler than ambient temperature for many hours. However, since many fuel distribution centers use above-ground storage tanks, which will tend to average within about 10°F of ambient temperature. This also means that transferring it to underground tanks will leave the fuel warmer for a similar period of time.
B.) Fuel stored in underground tanks cools to around 58° and will remain at that temperature pretty much year-round, depending on the depth of the tanks. I will grant that at higher latitudes this temperature may be cooler (say, in central or northern Canada and Alaska, where summertime temps barely break 70°, if ever) but in the continental US, the average should be about 60°.
What's going to be the hot limiter in this issue isn't the temperature of the fuel, but rather the temperature of the automotive fuel tanks, likely to be significantly warmer, which will expand the fuel over time. If you fill your tank in the morning and let the car sit, you'll either see the fuel spill out the overflow or a flooded carburator. The only way to prevent this loss is to make sure you don't overfill your tank on hot days. This will not affect the amount of fuel you purchase and such legislation as discussed is literally a waste of time and taxpayer money.
That handy Wikipedia page has the formula for volume change based on temperature AND the coefficient of thermal expansion for gasoline.
5 gallons of gasoline at 60F expands to 5.02 gallons at 100F. Hope you don't let any gas drip out of the nozzle when you're done pumping!
More importantly, the cost of outfitting gas pumps (which will be passed on to the consumer) to correct for thermal expansion probably outweighs the "extra" gas dispensed.
@Andrew Farris:
Check the pump. If you see a certification sticker on that pump that is listed as still valid (not outdated) then that specific pump was measured for accuracy. There is no such thing as 'average' flow--the pump is measure for actual volume pumped.
Impossible. If the pump is certified by the state, the amount pumped should be no different at 50° than it is at 90°. Ten gallons is ten gallons. However, that ten gallons that might fill a car's gas tank in the winter might overflow that same tank in the summer.
@benh57:
Look at the pump itself. If it has a State Certification sticker, then the pump does account for this.
@David Fields: Thanks for the info. That's what I was going to point out. The temperature of the fuel tank in your car is going to have more of an effect than the outside temperature. Tanks are underground for a reason. Having wide swings in temperature of fuel while stored would wreck havoc on how many gallons they have and what can fit.
Also, think of caves, or even a ditch. The ground is much cooler there than the surface temperature.
My dad works for an oil company and has worked in maintenance on these things and now is in charge of construction of gas stations and has a lot of contact with tank installers. If I question the veracity of stories like this, I go to him first.
The millions that Costco will have to pay to fix this "problem" will only get passed onto the customers through higher prices overall in their store.
There will be no savings to Costco customers.
@Firethorn: Thank you. No one seems to have noticed your post yet, but the coefficient of thermal expansion is low enough to where this is pretty much irrelevant.
@David Fields: OMG my head hurts so much after reading your post. 10 gallons is 10 gallons -> a 10 gallon tank in winter will hold the same amount of volume in summer (actually, slightly more, since metal does expand a bit when hot, but it's a negligible difference). In addition, yes, assuming the pump is a perfect meter, it will pump the same VOLUME of gas be it summer or winter. What people are discussing here is the DENSITY / MASS of the gasoline you put in your car. If the gasoline is hot, it will be less dense, and you will have less mass per gallon = less energy per gallon, effectively increasing the cost of the energy you are getting from your gas. It's a pretty negligible change, but it's there.
@Firethorn:
That .069% per F. or 'mere' 7 cents difference per gallon adds up to billions for class action lawyers and just pennies for individual consumers.
@larrymac:
Living within 15 miles of a refinery, I can tell you that your latter statement, "proximity to refinery' is a farce. I've seen more than once how stations hundreds of miles from a refinery and almost 50 miles from a distributor have lower prices than stations within 2 mile of those same refineries/distributors. In all actuality, that remoteness is WHY their prices are lower; they have to charge less to pull customers away from the more visible stations.
@synergy: yes it is, you're wasting your time. try doing a few tanks when you fill up cold, and a few tanks when you fill up hot, compare your mpg, calculated as 'miles between fillups, as recorded by your odometer / tripmeter' / 'volume of fuel pumped' (do not use an on board computer for this calculation) and see if you see any variation. Any temperature effects will be significantly less than your normal driving variations.
I live in Arizona and have friends who get gas from Costco. This ain't good.
This whole scandal is BS from the start. The volume correction is just that, a CORRECTION for the volume change as a result of temperature change.
Your engine doesn't care how many gallons of fuel it's using, it cares how many moles (an expression of the number of molecules). There are fewer moles in a gallon of hot gas. That's what the CORRECTION takes care of. You're paying the same money for the same moles no matter what the temperature. They just sell gas in volumetric units (gallons in the US, litres in the rest of the world) rather than moles because people understand volume, but have to take a chemistry course to understand moles.
They should sell it by mass (pounds in the US, kilograms elsewhere), then we could dispense with all this silliness as it would be both understandable and immune to temperature fluctuations.
@ecwis: Below a few feet, the ground does stay a constant temperature. That temperature isn't 60°F everywhere, though - it's the average year-round temperature for that place. In upstate NY, that's around 52°F; in Arizona, it's around 68°F.
If you want to know what it is in your area, look up a local commercial cave and see if the cave temperature is listed.
@lincolnparadox: The temperature underground is about 50°F -- somewhere in Canada. It varies from place to place. (See my reply to ecwis above.) There isn't much of the US where the underground temperature is that low.
@Geekybiker: The Costco I work at has the same pumps. As a matter of fact, when I started at Costco I worked in the gas station, and there's a giant ass sticker explaining temperature regulations and the cause of expansion and shrinking.
Here's what everyone needs to understand; the majority of Costco members are oblivious and don't know how/care to read signs.
Honestly, this is just a little ridiculous. What about air inflation in tires? When a tire runs hot, the air expands. Cold? The molecules contract. Are we going to start filing lawsuits against gas stations that charge for air?
The gods either love maple syrup or hate Texas.