| reply to IowaCowboy
Re: Weights and measures said by IowaCowboy:When you pay for a gallon of gas, it should be a true gallon of gas.
It is always a gallon of gas, but due to temperature fluctuations, it may not be the same mass due to higher densities in cold temperatures, and lower densities in warmer temperatures. |
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| said by talz13:It is always a gallon of gas, but due to temperature fluctuations, it may not be the same mass due to higher densities in cold temperatures, and lower densities in warmer temperatures. Which is why Costco pumps have a label on them now stating that they sell gas by volume not energy content. Some ambulance chaser thought they could win a lawsuit because the pumps weren't temperature compensating. |
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 BF69Premium
join:2004-07-28
Camden, TN | reply to talz13
said by talz13:said by IowaCowboy:When you pay for a gallon of gas, it should be a true gallon of gas.
It is always a gallon of gas, but due to temperature fluctuations, it may not be the same mass due to higher densities in cold temperatures, and lower densities in warmer temperatures. Small fluctuations are expected. If someone's data is off 20% that's an issue. Even 5% is an issue. |
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| reply to talz13
said by talz13:said by IowaCowboy:When you pay for a gallon of gas, it should be a true gallon of gas.
It is always a gallon of gas, but due to temperature fluctuations, it may not be the same mass due to higher densities in cold temperatures, and lower densities in warmer temperatures. In Canada, the gas is sold volumetric corrected to a temperature of 15C, which is the typical temperature of the gasoline in the underground tanks at the depth they are buried. Since the path of the gasoline in the above-ground portion of the pump is short there is no appreciable need to correct for the ambient atmospheric temperature.
You *might* gain some energy content advantage is you filled up in the winter just after the underground tanks were replenished, if the tanker had traveled 200 miles in -20F weather and chilled the gasoline. |
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Reviews:
 ·RoadRunner Cable
| reply to BF69
I agree. While I'm typically not for 'regulation', I would have to state that if companies that are using meters for profit, those meters should be certified for use by an independent company.
Eg. Household electric meters, gas meters, water meters, grocery store scales, gas station pumps, etc.
If AT&T is going to bill by the byte, then their billing must conform to a standard, and their devices must be certified for accuracy.
I should not be paying for external broadcast packets that do not make it to the LAN side of the modem, or corporate sniffers. |
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 cdruGo ColtsPremium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7 | reply to MaynardKrebs
said by MaynardKrebs:You *might* gain some energy content advantage is you filled up in the winter just after the underground tanks were replenished, if the tanker had traveled 200 miles in -20F weather and chilled the gasoline. To quantify that amount...
Gasoline expands about 1.2ml per liter per 1 degree C increase in temperature. The variation between -20F and the baseline 15C is approximately 44C. That gives you the equivalent additional energy as an extra 52.8mL at the baseline temp, or a 5.28% advantage. Putting that in terms of units Americans would understand, that's like getting an extra 7/8ths of a cup of gas per gallon.
It usually averages out though for non-ATC pumps. Because for tanks that you might get at -20F, you may also get gas at 80 or 90 degrees and you lose the advantage. |
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| said by cdru:.......That gives you the equivalent additional energy as an extra 52.8mL at the baseline temp, or a 5.28% advantage. Putting that in terms of units Americans would understand, that's like getting an extra 7/8ths of a cup of gas per gallon.
52ml is roughly 20% of a standard 8oz./250ml 'cup', or approximately 2 ounces or 1/4 cup.
Anyone have any idea what the typical temperature of gasoline is when it's held in above ground tanks at the refiners terminal, and how much hat temperature varies though the year in different climatic zones? |
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 chambercPremium
join:2008-08-05
Irving, TX
·Time Warner Cable
| reply to travelguy
said by travelguy:said by talz13:It is always a gallon of gas, but due to temperature fluctuations, it may not be the same mass due to higher densities in cold temperatures, and lower densities in warmer temperatures. Which is why Costco pumps have a label on them now stating that they sell gas by volume not energy content. Some ambulance chaser thought they could win a lawsuit because the pumps weren't temperature compensating. Take E85. A gallon has 1/3 less energy content, so therefore it takes 1/3 more E85 to go the same distance as gas.
I always laugh when I see people filling up with E85 thinking they're paying less, and yes, I ran two tanks of the crap to confirm. My gas mileage dropped from 12 mpg to 8. |
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