

| Subject: | Re: Gas consumption higher in winter? |
| From: | Dennis Haynes |
| Date: | Fri, 30 Nov 2012 17:40:43 -0500 |
In many marine and industrial application fuel consumption is often rated by pounds/hour or a metric equivalent. Dennis -----Original Message----- From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Marc Perdue Sent: Friday, November 30, 2012 5:11 PM To: vanagon@GERRY.VANAGON.COM Subject: Re: Gas consumption higher in winter? 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 >
Have something to add on this topic today? Revive this thread in the forum »