Date: Fri, 30 Nov 2012 17:40:43 -0500
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Gas consumption higher in winter?
In-Reply-To: <CAEwp_cQtUHe92JEX6dMr00wo0_wC2yf_2FzLK4kRF9kK5fKEYA@mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"
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 @ 60º 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 @ 80º
> > >> is 233.7CuIn
> > >>
> > >> & @ 30º 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
>
| 
