Some interesting facts regarding gasoline expansion with temperature:
25 gal of gasoline at 30?F expands to 26 gal at 90?F. (It expands 1% for every 15?F rise in temperature.
In the U.S. gas is sold by oil companies to wholesalers in units called “US Petroleum Gallons,” which is defined as 231 cu. in. of volume at 60?F.(Meters on fuel tanker pumps are temperature compensated.)
In the U.S. gas is sold retail at gas stations in units called “US Standard Gallons,” which is defined as 231 cu. in. of volume regardless of temperature.
In Canada meters at gas stations are temperature compensated, so that a liter of Canadian gas is only a true liter (1000 cu. cm.) at about 15?C. If one buys gas in Canada on a day when the temperature falls below 15?C, the actual gas volume delivered by the pump is reduced.
In California many gas stations run the gasoline through piping mazes in the roofs of the canopies over the pumps to warm it from the temperature of the subterranean tanks. The STATED reason is that when the cold gasoling warms up in the tanks of the cars it will outgas and cause air pollution. That might be the case if the car just sat there and didn’t burn up gasoline driving away. I have noticed that most cars do leave the gas stations.
In California many gas stations run the gasoline through piping mazes in the roofs of the canopies over the pumps to warm it from the temperature of the subterranean tanks. The STATED reason is …
So you think the gas stations are doing a little ‘pre-warming’ for the sake of the environment? What a noble idea!
Or perhaps it is to ‘lighten-up’ the weight a car has to carry after leaving the gas station? Don’t think this does not add up to big $$$:
Temperature compensation for fuel) is a
tremendous windfall for fuel dealers across
the country, in the amount of millions of
dollars annually.
I am a Metrologist [one of the weights
and measures guys) and we set the
measures which compare the volume of gas
sold at the pumps.
Fuels nationwide are measured to be sold at
60 degrees F [except in Hawaii which
is at 85F]. Meters at the gas station are not
temperature compensated. When the ambient
temperature is above 60 degrees, you get
less fuel (thus less BTU’s) for you money,
of the “expanded” fuel in the dealers tank
is sold until it is gone. If they buy 1000
gallons, they are selling through the meter,
much more. This is based simply on the
cubical coefficient of expansion.
Most states have an average temperature of
more then 60 degrees F, including us in Maine in the
summer time. Of course, in the winter, this
situation is reversed, but in terms of
degree days, we are the minority.
Fuel producers and dealers have resisted
temperature compensation of fuels for many
years. It is funny the in Canada they
embrace it, and temperature compensated
meters are at every gas station in the
country.
Also, your concept of selling fuel by weight
would be rather difficult owing to the
weight of proprietary additives in most
fuels.
Your answer about the small amount of fuel
lost is kind of like the old saying
“I lose a little on every transaction–but
I make it up in volume!”
George O’Connor
I heard Tom and Ray answer a question from a
listener in Chapel Hill, NC regarding a bet
he had on whether to fill out his gas tank in
the cooler morning/evening as opposed to the
midday. Their answer was that it was true
that the cooler temps increased the density
of the gas in the tank, but that the increase
was too small to really matter. I think the
answer was only half right. I agree
that the density does increase as temps cool
down, but it can make a sizable difference
when we factor in geography and scale.
Certainly in the cool air of Chapel Hill or
in the Frozen North of Boston it will not
matter much. But here in Lost Wages, Nevada
and other places around the country where it
is hot and hotter all year round, when you
consider the 30 degree temp. range in a
single day along with the fact that there are
hundreds of gas stations and millions of
drivers in these areas and the gas tanks at
stations are not too far below our ground
with its already warm mean ground temp,
having everyone fill out their tanks in the
early morning or evening will have an effect.
Newscasters here Lost Wages regularly remind
listeners in the summer when we get into 3
digit tempts to do just that.
What might be insignificant at
a personal level becomes significant when
scaled up to the social level.
Geoffrey Frasz, Las Vegas, NV
Aloha,In Hawaii,state law requires our gallon of gas to be 1% greater volume due to the higher average ambient temp.80 VS. 60 degrees on the mainland.Just another advantage of living in Paradise.OK,I gotta go surfing.Maholo Lopaka Honolulu
It’s not just increased demand that sends summertime gasoline prices soaring. It’s also the increased temperature.
As the temperature rises, liquid gasoline expands and the amount of energy in each gallon drops. Since gas is priced at a 60-degree standard and gas pumps don’t adjust for any temperature changes, motorists often get less bang for their buck in warmer weather.
Consumer watchdog groups warn that the temperature hike could cost consumers between 3 and 9 cents a gallon at the pump.
The effect could cost U.S. drivers more than $1.5 billion in the summertime ? including $70 million to drivers in Arizona alone, according to the House Subcommittee on Domestic Policy, which recently addressed it in hearings. The committee’s chair, Rep. Dennis Kucinich, D-Ohio, has long been an advocate on the issue and has new clout as a member of the congressional majority.
Gas retailers say forcing stations to adjust their pumps would be too costly, and they asked Kucinich to call off the hearings and wait for more studies.
The issue has driven trial lawyers to file as many as 20 federal lawsuits accusing retailers of using simple physics to take advantage of consumers. Challenges have been filed in Alabama, Arkansas, California, Florida, Kansas, Missouri and New Jersey, among other states, and some are seeking class-action status.
The latest lawsuit, filed last week in federal District Court in Georgia, claims that distributors have been “unjustly enriched” by tens of millions of dollars. They did so by paying taxes on the fuel based on the colder industry standard but pocketing the taxes collected from customers when the temperature soars, it alleged.
The “hot fuel” effect is a matter of simple physics.
Almost a century ago, the industry and regulators agreed to define a gallon of gasoline as 231 cubic inches at 60 degrees. But as the mercury rises and gasoline expands, it takes more than a gallon of gas to produce the same amount of energy. The opposite is true when gasoline contracts in colder weather.
U.S. gas retailers ignore the temperature swings and always dispense fuel as if it’s 60 degrees. As a result, gas is an average of about 5 degrees warmer than the federal standard, according to a study analyzed by Dick Suiter of the National Institute of Standards and Technology.
According to the National Oceanic and Atmospheric Administration, the average U.S. temperature in May was 63 degrees; average for all of 2006 was 55 degrees. But drivers fare worst in Southern and Western states where the temperatures are the most consistently warm.
The average temperature in Tucson in May was 78 degrees.
Increased demand also sends gas prices higher during the peak summer travel season, so the effect of paying more for less in the warmer months is more pronounced.
The impact isn’t lost upon Carl Rittenhouse, a carpet worker from the north Georgia town of Chatsworth.
“You can tell the difference between the time you fill up in the morning or night, or if you fill up in the middle of the day,” said Rittenhouse, who joined one of the lawsuits. “All you have to do is look at the fumes.”
Lawmakers join discussion
The debate is now reaching Washington.
Sen. Barbara Boxer, D-Calif., recently urged California lawmakers to take action. And Kucinich earlier this month called a hearing on the issue, calling it “Big Oil’s double standard.”
“People are paying for gasoline they’re not getting,” said Kucinich, who is running for president.
Lawmakers don’t have to look far for possible solutions.
In frigid Canada, where cold temperatures were giving consumers an edge, many gas stations voluntarily backed a program to add pumps that automatically adjust volumes based on temperature.
During the energy crisis in the 1970s, tropical Hawaii decided to set a base fuel temperature of 80 degrees, meaning that consumers there get more bang for their buck because retailers now dispense 234 cubic inches of gas per gallon rather than 231.
The federal government is considering a similar change as well. The National Conference on Weights and Measures is to vote in July on whether to allow temperature regulation by retailers.
The upcoming decision is worrying some fuel distributors, who say the new equipment could force some independent dealers out of business.
NATSO, a trade group representing truck stop owners, estimates that each retrofitted pump could cost between $1,500 to $3,800.
“The average truck stop has 20 pumps,” said Mindy Long, a spokeswoman for the group. “The burden on them would be phenomenal.”
NATSO and other gas retailers have formed a group called PUMP ? the Partnership for Uniform Marketing Practices ? which is calling for more studies on the issue before taking any action.
Well,I feel so much better knowing Rep. Dennis Kucinich, D-Ohio is on it!!!
quote:
[Lack of] temperature compensation for fuel is a tremendous windfall for fuel dealers across the country, in the amount of millions of dollars annually …
I could not agree more with your entire post.
I’m glad I started this thread.
Listening to your answer to the caller about
pumping gasoline at a lower temperature to
get more carbon for your buck reminded me
that I had just read an article I just read
last week (I believe it was in the Wall
Street Journal).
It seems that the pumps are calibrated to
deliver one gallon at 60 degrees F. The feds
are considering requiring all pumps to be
modified to compensate for temperature
variations. I don’t recall the differences
they calculated, but they were fairly small.
I don’t suppose the volume coefficient of
expansion of gasoline is a very large number.
Of course, the cost of retrofitting the pumps
is fairly high and the small gas stations are
saying they could not afford to do this. Your
government at work. Someone there doesn’t
have much to do.
quote:
[i]The feds are considering requiring all pumps to be modified to compensate for temperature variations. I don’t recall the differences they calculated, but they were fairly small. I don’t suppose the volume coefficient of expansion of gasoline is a very large number.
Of course, the cost of retrofitting the pumps is fairly high and the small gas stations are saying they could not afford to do this. Your government at work. Someone there doesn’t have much to do.[/i]
A car with a 20 gal tank that gets 25 mpg with gasoline at 60?F will get 490 miles per fill-up with 90?F gasoline and 510 miles with 30?F gasoline. That is the difference. It’s not small given the total number of cars.
The volumetric coefficient of expansion of gasoline is 1% per 15?F. Give a toot if there is anything else you would like to know.
The small gas stations in Canada decided they could afford the cost of retrofitting their pumps when they saw how much money they were losing in cold-climate Canada. All the gas stations in Canada voluntarily changed their pump meters to temperature-compensated meters at their own expense.
Yes, your government at work. It’s more difficult when we have to deal with people like you.
The typical storage tank is buried 10 feet underground where there is very little temperature variation. I think you will find 60 degrees fuel temperature is a good year-round average. Most of the expansion and contraction occurs in your tank, after YOU own the fuel, not the oil company…
Don’t worry,with man made global warming it won’t matter.But,these folks would find something else to complain about.
I am providing an article under the fair use clause about the topic of Hot Gas.
Hot Gas in the News
Is ‘hot fuel’ costing motorists?
Lawyers, politicians argue about how weather
affects prices at the pumpBy Greg Bluestein
The Associated PressJune 25, 2007
ATLANTA – It’s not just increased demand
that sends summertime gasoline prices
soaring. It’s also the increased temperature.As the temperature rises, liquid gasoline
expands and the amount of energy in each
gallon drops. Since gas is priced at a
60-degree standard and gas pumps don’t adjust
for any temperature changes, motorists often
get less bang for their buck in warmer weather.Consumer watchdog groups warn that the
temperature hike could end up costing
consumers between 3 and 9 cents a gallon at
the pump – adding up to hundreds of millions
of dollars each year.The effect could cost U.S. drivers more than
$1.5 billion in the summertime, including
$228 million to drivers in California alone,
according to the House Subcommittee on
Domestic Policy, which recently addressed it
in hearings. The committee’s chair, Rep.
Dennis J. Kucinich, D-Ohio, has long been an
advocate on the issue and has new clout as a
member of the congressional majority.Gas retailers oppose forcing stations to
adjust their pumps as costly, and asked
Kucinich to call off the hearings and wait
for more studies.The issue has driven trial lawyers to fire
off as many as 20 federal lawsuits accusing
retailers of using simple physics to take
advantage of consumers. Challenges have been
filed in Alabama, Arkansas, California,
Florida, Kansas, Missouri and New Jersey,
among other states and some are seeking
class-action status.The latest lawsuit, filed last week in
federal district court in Georgia, claims
that distributors have been “unjustly
enriched” by tens of millions of dollars.
They did so by paying taxes on the fuel based
on the colder industry standard but pocketing
the taxes collected from customers when the
temperature soars, it alleged.“I don’t believe gas retailers should collect
more in purported taxes than they pay the
government,” said Bryan Vroon, one of the
attorneys in the Georgia suit. “Gas prices
are high enough without the over-collection
of taxes.”The “hot fuel” effect is a matter of simple
physics.Almost a century ago, the industry and
regulators agreed to define a gallon of
gasoline as 231 cubic inches at 60 degrees.
But as the mercury rises and gasoline
expands, it takes more than a gallon of gas
to produce the same amount of energy as a
regular gallon in colder weather.U.S. gas retailers ignore the temperature
swings and always dispense fuel as if it’s 60
degrees. As a result, gas is an average of
about five degrees warmer than the federal
standard, according to a study analyzed by
Dick Suiter of the National Institute of
Standards and Technology. But it’s worst in
southern and western states where the
temperatures are the most consistently warm.According to the National Oceanic and
Atmospheric Administration the average U.S.
temperature in May was 63 degrees; average
for all of 2006 was 55 degrees.The impact isn’t lost upon Carl Rittenhouse,
a carpet worker from the north Georgia town
of Chatsworth.“You can tell the difference between the time
you fill up in the morning or night, or if
you fill up in the middle of the day,” said
Rittenhouse, who joined one of the lawsuits.
“All you have to do is look at the fumes.”The debate is now reaching Washington.
Sen. Barbara Boxer, D-Calif., recently urged
California lawmakers to take action. And Rep.
Kucinich earlier this month called a hearing
on the issue, calling it “Big Oil’s double
standard.”“People are paying for gasoline they’re not
getting,” said Kucinich, who is running for
president.Lawmakers don’t have to look very far for
possible solutions.In frigid Canada, where cold temperatures
were giving consumers an edge, many gas
stations voluntarily backed a program to add
pumps that automatically adjust volumes based
on temperature.During the energy crisis in the 1970s,
tropical Hawaii decided to set a base fuel
temperature of 80 degrees, meaning that
consumers there get more bang for their buck
because retailers now dispense 234 cubic
inches of gas per gallon rather than 231.The federal government is considering a
similar change as well. The National
Conference on Weights and Measures is to vote
in July on whether to allow temperature
regulation by retailers.The upcoming decision is worrying some fuel
distributors, who say the new equipment could
force some independent dealers out of
business. NATSO, a trade group representing
truck stop owners, estimates that each
retrofitted pump could cost between $1,500 to
$3,800.“The average truck stop has 20 pumps,” said
Mindy Long, a spokeswoman for the group. “The
burden on them would be phenomenal.”NATSO and other gas retailers have formed a
group called PUMP – the Partnership for
Uniform Marketing Practices – which is
calling for more studies on the issue before
taking any action.They have a powerful ally in Rep. Bart
Gordon, the Tennessee Democrat who chairs the
House Committee on Science and Technology. In
a May letter to the National Academy of
Sciences, he suggested the idea of
retrofitting pumps may be “premature.”The trucking companies and motorists behind
the lawsuits hope they could force
politicians to act quicker.“You’re not getting as much as what you’re
paying for, really,” said Rittenhouse, the
north Georgia motorist. “Most folks don’t
have a clue. But it’s costing them.”Copyright ? 2007, The Associated Press
quote (by Caddyman):
The typical storage tank is buried 10 feet underground where there is very little temperature variation. I think you will find 60 degrees fuel temperature is a good year-round average.
Caddyman, you are absolutely WRONG !!! Large gas stations monitor the gasoline temperature in their tanks in order to correct their volume measurements when testing for tank leakage. The results are printed out on a little slip of paper which looks like a gasoline receipt.
Here is one:
You will see that the temperatures in the two tanks are 82.5?F and 82.4?F, and not the 60?F year-round average as you erroneously claim. Also notice that the total measured tank volume is 33,683 gallons while the temperature corrected tank volume is 33,343 gallons, or a difference of 340 gallons. Those 340 gallons are “heat-created” gallons that the station got for free; only the consumer is paying for it.
quote (by Caddyman):
Most of the expansion and contraction occurs in your tank, after YOU own the fuel, not the oil company…
Yeah, sure … tell me about it.
Where in the world is there a buried tank that sees 82 deg F? Nowhere I have ever lived. My basement is a consistently lower temp than 82 deg ( more like 60 deg F) due to the relatively constant temp underground. This is the reason why heat pumps work in so many areas of the country. For the vast majority of the continental US, a tank buried up to 10 ft underground isn’t going to be 82 deg F.
At any rate, the difference in fuel bought between cool mornings and hot afternoons (especially at stations with above ground storage!) amounts to far more than the 1/10 of a cent that was jokingly thrown out as the “gain” on the show…
quote (by anonymous ?)
Where in the world is there a buried tank that sees 82 deg F? Nowhere I have ever lived. My basement is a consistently lower temp than 82 deg ( more like 60 deg F) due to the relatively constant temp underground. This is the reason why heat pumps work in so many areas of the country. For the vast majority of the continental US, a tank buried up to 10 ft underground isn’t going to be 82 deg F.
First of all, I don’t know why I bother to respond to a post by someone who calls themselves Anonymous. Do you have a name, or are you a member of the Federal Witless Protection program?
Those gas tanks are doubled lined fiberglass with an air space between fiberglass layers. I don’t want to compute the R-factor of the walls (at least not for you), but the R-factor is high. The tanks are filled with gasoline at air temperature the day the gasoline is delivered. Think about it: Hot delivered gasoline, large volume of gasoline, high R-factor of double fiberglass storage walls = low rate of heat outflow into surrounding ground.
Get a Fluke Meter with a heat probe and actually measure the temperature of gasoline as it comes out of the underground storage tanks. Real data. I have witnessed it. I don’t want to hear anecdotal stories about the temperature in your basement.
Do you really think I fabricated that temperature receipt from a truckers’ stop near Kansas City which I posted above? Temps of 82?F in the tanks?
Nice to hear from you again, Anonymous. I’ll post a reply if you ever come back again with a real name.
In Russia vodka is sold in grams instead of in mililitres. I suppose it’s to prevent people from thinking they are getting ripped off for the reasons you cite. Drinking is serious business in Russia like driving is in the US.
I said “average”. In January, the station owner, if different from the company who refined the fuel, will be “short” those same gallons as the liquid temperature slips below 60 degrees. Over say a two year period, the volume measurement equals out and 60 degrees will be very close to the actual average temperature. I suspect fuel dispensers in the near future will automatically compensate volume for temperature and tankwagon loads will be temperature corrected too…