When Is A Gallon of Gas Not A Gallon of Gas?
You probably heard one of the ways to increase your gas mileage is by filling your vehicle during the coolest part of the day. I thought about this as I stood in 107° heat, feeding my car’s nasty gasoline habit, looking at the State’s calibration sticker on the pump and trying not to go into a heat-induced delirium. Or maybe I did because it occurred to me that the State had certified that that I should be getting a gallon of gas. Yet gas changes its density with temperature. High temperature, less gas per volume. So how can the State say that my gallon of gas is in fact a gallon of gas?
This question became like a bad song stuck in my head. It intrigued me enough that I had to do a little research. Apparently, a gallon of gas has been standardized at 231 cubic inches at 60°F since the 1920s. The thing about gasoline is that it expands as the temperature rises. As the temperature goes up, there’s less gasoline in that cubic inch. The reverse is true as well. The colder it gets, the more gasoline energy is available in that cubic inch. So if you are the owner of a gas station, you got to love those hot summer days when mother nature helps you overcharge for a gallon of gas without you having to do a thing. Of course, if you live in a generally cold climate, the consumer is the one reaping this benefit. This explains why gas pumps in Canada have temperature adjusting devices. We can’t have oil companies and gas retailers losing money during those cold months, now can we.
What about Canada’s warmer neighbor to the south? I learned that while the gas industry routinely makes price adjustments to its wholesalers based on the temperature fluctuations, the consumers see none of this. But don’t worry. It looks like a few other people have wondered about this discrepancy too. I learned that more than 20 lawsuits have been filed in seventeen states by truck drivers and motorists. These lawsuits seek to have gas pumps fitted with temperature compensation equipment so that when you pay for a gallon of gas, you get a gallon of gas regardless of how warm or cold it is. The response from the fuel industry is … it would cost them too much. I guess it would. It’s as if you bought five apples from someone and they can get away with giving you just four apples. Of course it would “cost” them money if they were forced to give you what you paid for in the first place.
As I read more about this gas cost verses temperature, I wondered if there might be a balancing of costs between gas stations and consumers over the course of a year. If you bought the same dollar amount of gas every day for one year, who would come out ahead? You or the gas station? So here is a picture that shows the average yearly temperature in the US during 2001. The red line shows our 60°F demarcation line.
In our little scenario, if you were buying gas north of the red line everyday, it looks like you’d benefit. If you were selling gas south of the red line, then you would be benefiting at your customers’ expense. Of course, this picture and our little scenario are misleading. I’ve lived in places where where it has been 40° in the morning and 70° by the afternoon. And there are studies that there’s much more traveling done in the summer than in the winter. So I guess it can’t really be argued that there is a balancing in cost between gas stations and the customers.
Until the courts sort this out, I don’t know what you and I can do about it. For now, all we can do is gas up during the coolest part of the day. And yesterday started out at 80° for me … maybe I should just move to Alaska.
Popularity: 16% [?]
You probably heard one of the ways to increase your gas mileage is by filling your vehicle during the coolest part of the day. I thought about this as I stood in 107° heat, feeding my car’s nasty gasoline habit, looking at the State’s calibration sticker on the pump and trying not to go into a heat-induced delirium. Or maybe I did because it occurred to me that the State had certified that that I should be getting a gallon of gas. Yet gas changes its density with temperature. High temperature, less gas per volume. So how can the State say that my gallon of gas is in fact a gallon of gas?
This question became like a bad song stuck in my head. It intrigued me enough that I had to do a little research. Apparently, a gallon of gas has been standardized at 231 cubic inches at 60°F since the 1920s. The thing about gasoline is that it expands as the temperature rises. As the temperature goes up, there’s less gasoline in that cubic inch. The reverse is true as well. The colder it gets, the more gasoline energy is available in that cubic inch. So if you are the owner of a gas station, you got to love those hot summer days when mother nature helps you overcharge for a gallon of gas without you having to do a thing. Of course, if you live in a generally cold climate, the consumer is the one reaping this benefit. This explains why gas pumps in Canada have temperature adjusting devices. We can’t have oil companies and gas retailers losing money during those cold months, now can we.
What about Canada’s warmer neighbor to the south? I learned that while the gas industry routinely makes price adjustments to its wholesalers based on the temperature fluctuations, the consumers see none of this. But don’t worry. It looks like a few other people have wondered about this discrepancy too. I learned that more than 20 lawsuits have been filed in seventeen states by truck drivers and motorists. These lawsuits seek to have gas pumps fitted with temperature compensation equipment so that when you pay for a gallon of gas, you get a gallon of gas regardless of how warm or cold it is. The response from the fuel industry is … it would cost them too much. I guess it would. It’s as if you bought five apples from someone and they can get away with giving you just four apples. Of course it would “cost” them money if they were forced to give you what you paid for in the first place.
As I read more about this gas cost verses temperature, I wondered if there might be a balancing of costs between gas stations and consumers over the course of a year. If you bought the same dollar amount of gas every day for one year, who would come out ahead? You or the gas station? So here is a picture that shows the average yearly temperature in the US during 2001. The red line shows our 60°F demarcation line.
In our little scenario, if you were buying gas north of the red line everyday, it looks like you’d benefit. If you were selling gas south of the red line, then you would be benefiting at your customers’ expense. Of course, this picture and our little scenario are misleading. I’ve lived in places where where it has been 40° in the morning and 70° by the afternoon. And there are studies that there’s much more traveling done in the summer than in the winter. So I guess it can’t really be argued that there is a balancing in cost between gas stations and the customers.
Until the courts sort this out, I don’t know what you and I can do about it. For now, all we can do is gas up during the coolest part of the day. And yesterday started out at 80° for me … maybe I should just move to Alaska.
Popularity: 16% [?]
Written by sprezzaturon in: ,breast reduction,breast size,socialism,XM |5 Comments »
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Excellent post! I’ve been purchasing my petrol in the morning as often as possible, and I have noticed the difference! My mileage goes from 24 mpg to 20 mpg when I purchase while the temperatures are up. Thanks for sharing, your post makes perfect sense even for those of us who know little about science.
I really enjoyed this. I never gave it any thought – just fill up when I happen to be out, low on gas, and driving by a gas station. They do tell us on our local news not to fuel up when it is extremely hot and humid, but I think that has to do with the atmosphere and ozone and not with helping us save money.
Susan: I’m working on a follow-up post that gives actual numbers for your gas mileage and your dollars-per-gallon cost. Hopefully, you’ll enjoy that one too!
Anna: I was hoping that my post made sense. As I mentioned previously, I’ll be posting some practical numbers for us in the near future. Thanks for writing!
Thanks for such a great post and the review, I am totally impressed!
I love when I have free time to check out blogs online. I learn a lot from then and many are very funny. Keeping a smile on my face while relaxing is always a pleasure! Thanks for sharing yours.