

| Subject: | Re: Gas consumption higher in winter? |
| From: | Marc Perdue |
| Date: | Fri, 30 Nov 2012 17:10:48 -0500 |
Wouldn't they have to heat the gas in the underground storage tanks? The ground temp usually runs 45-55 degrees F below the frostline . . . On Fri, Nov 30, 2012 at 4:56 PM, Dave Mcneely <mcneely4@cox.net> wrote: > ---- OlRivrRat <OlRivrRat@comcast.net> wrote: > > This from Wikipedia > > Which is in complete agreement with what I said, as is the other site you > referenced. But, I did not know that a standard commercial gallon was > measured at 60 F. To compensate, the pump would have to measure the > temperature, and integrate an algorithm to adjust the metered volume to > what that volume would be if the temperature were 60 F. Since chips and > programming are now cheap, that would not be hard to do, but it would add a > tiny increment to cost. > > thanks for the links. mcneely > > > > "The US liquid gallon > > > > The US gallon, which is equal to 3.785411784 litres is legally defined > > as 231 cubic inches.[1] [2] There are four quarts in a gallon, two > > pints in a quart and sixteen fluid ounces in a pint. In order to > > overcome the effects of expansion and contraction with temperature > > when using a gallon to specify a quantity of material for purposes of > > trade, it is common to define the temperature at which the material > > will occupy the specified volume. For example, for purposes of trade, > > the volume of petroleum products[3] and alcoholic beverages[4] are > > both referenced to 60 �F (16 �C)." > > > > So lets say that the gas you pump is @ 60� in the > > UndergroundStorageTank, after a short period of time in your GasTank > > it will adjust to AmbientTemp' so in the Summer it will Expand to More > > Gal's & in the Winter it will Shrink to Less Gal's. > > I started looking into this thanks to Costco (where, until > recently, > > I never bought gas) as there is a Sticker on their pumps that states > > that the Gal' of Gas that they charge you for is 231CuIn as measured > > by the pump. > > This is an interesting PDF ~ > www.nh.gov/agric/news/documents/weights-fuel-temperature.pdf > > ~ I stumbled on to it earlier when I Googled "gas pump gallon volume" > > > > ORR ~ DeanB > > > > > > > > On 30 Nov , 2012, at 12:28 PM, Dave Mcneely wrote: > > > > > ---- OlRivrRat <OlRivrRat@COMCAST.NET> wrote: > > >> Also keep in mind that the vol' of a > > >> Gal'OfGasoline @ 80� is 233.7CuIn > > >> > > >> & @ 30� it is 227.0CuIn so you actually have less GasByVolume in your > > >> tank in the Winter > > >> > > >> than in the Summer but I haven't really thought through what effect > > >> that might have on > > > > > > Hmmmm........... . Do you mean that a gallon is not always a > > > gallon? Is the gallon you cite a gallon at standard temperature and > > > pressure (O C, 760 mm Hg) but a bit bigger at warmer temperatures? > > > Because a gallon is a measure of volume. The fuel may expand and > > > shrink, but then it won't be a gallon any more, it'll be something > > > else. > > > > > > Now, if you cited a variable volume for a given mass of fuel (again, > > > the weight but not the mass could vary depending on where the > > > measurement was made), then we'd be getting somewhere. If you want > > > the same exact amount of fuel regardless of conditions, you need to > > > deal with mass, so as to have the exact same number of molecules. > > > > > > If you put in a gallon of fuel at one temperature, then the stuff > > > expands as it warms up, there is still no more fuel in the tank, it > > > just takes up more volume, more than a gallon. Same if it shrinks, > > > it now takes up less volume, less than a gallon. The amount of fuel > > > does not vary, just the space it occupies. > > > > > > If you buy a gallon of fuel that is cold, and another time buy a > > > gallon of fuel that is warm, the second time you get less fuel. > > > > > > All this would suggest that one might get better mileage (miles per > > > gallon) in winter, since by burning a gallon of fuel, one burns more > > > fuel, but other variables seem to obviate that. At least they do > > > for me, as I get poorer mileage in winter, by subjective judgement, > > > anyway. Of course, to be sure, we'd need a controlled experiment > > > that is probably beyond our ability to design and carry out given > > > the limitations of available vehicles and ability to control > > > variables. > > > > > > mcneely > > > > -- > David McNeely >
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