andy levy <andy-dml@levyclan.us> wrote:
: On 10/10/2006 22:09, Eric Hufstedler wrote:
:>> Hm. Interesting. I don't remember them changing that much. But a
:>> 10 deg. C change in temperature for 20 litres of gasoline
:>> increases the volume by almost 10%...? Wow. (Free gas!)
:>
:> Yep, that's why "they" say to buy gas in the morning, since the
:> pumps charge by volume, not weight.
: "They" also seem to forget that the gas is stored in underground tanks
: where the temperature is more or less constant. For the amount of time
: the gas is above ground where it can warm up, it won't warm up 10 degrees C.
Yep - I have heard gas station owners complaining about this -
when the semi arrives with their fuel, the fuel will basically be
at ambient temperature, or possibly more if the truck has been
sitting in the hot sun. The fuel gets dumped into their underground
tanks where it cools and shrinks, so not all of the fuel that they
purchased can be pumped back out into cars; for a busy station, this
can apparently really add up over the course of the year.
I suppose the stations in areas where we get cold weather
would benefit from the opposite effect; the fuel in the semi
would get nice and cold and then warm up and expand when it
hits the underground storage tanks.
This all assumes of course that the fuel is metered from
the truck, as opposed to a fixed amount being metered at the
distillery, all of which is simply dumped into the tanks at
the station. If that's the case, then it may just cancel
itself out, if the distillery is also using underground tanks.
Based on the stickers that Jason has seen, it sounds like they
might be compensating for this though, so maybe its a moot issue.
Anyhoo, just figured I'd throw that in there, as I have
heard gas station owners complaining about this in the past.
I definitely agree with Andy though, even a tractor trailer
taking on hundreds of gallons at a time probably wouldn't see
an appreciable benefit from this effect; as long as it is in
underground storage tanks, that gas is going to be coming out
of the pump at the same temperature year round. Some stations
do store it in above ground tanks, but even then, I don't see
thousands of gallons of gas varying in temperature a whole lot
from day to night, certainly not enough to bother waking up so
early in the morning. ;-)
--
-Jon-
.- Jon Steiger -- jon@dakota-truck.net or jon@jonsteiger.com -.
| '96 Kolb Firefly, '96 Suzuki Intruder, Miscellaneous Mopars |
`-------------------------------- http://www.jonsteiger.com --'
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