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'[EE] Fuel economy measurement across the globe'
2008\07\09@175844 by Bob Blick

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Apropos of the "best calculator" thread, I am curious about the
different methods of measuring vehicle fuel economy across the globe.
Being from the United States I am of course ignorant of what system
anyone else uses. But I am enlightened enough to know that other people
have different ways of doing things.

Just for the record, in case anyone is curious, in the USA we measure
fuel economy in Miles per Gallon, where a mile is about 1609 meters and
a gallon is about 3.78 liters.

And I bet that in parts of the United Kingdom they also use Miles per
Gallon, but maybe those are Imperial Gallons(4.54 liters).

For sure in true metric countries they must use metric units, but I have
heard it's reversed, and "Liters per 100 Kilometers" is a typical way of
specifying fuel economy. If this is so, is this the norm?

So if you want to chime in with how you specify fuel economy and where
you live, it would be much appreciated (and the information will be used
in an upcoming open source PIC project).

Thanks!

Cheerful regards,
Bob

--
http://www.fastmail.fm - A fast, anti-spam email service.

2008\07\09@180708 by piclist

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It's worse than just having various types of units.

You also have to define how you measure it.  Your MPG will vary bases on
how fast you are driving.  And if you have to speed up and slow down. Or
stop.  Or idle.  Or go up and down a hill.

The US recently changed how they calculate city milage, and suddenly all
the cars now get worse city fuel economy.  Well the stated numbers go
down, the actual economy (or lack of it) has not changed.

--
Ian Smith
http://www.ian.org

2008\07\09@182516 by Bob Blick

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On Wed, 9 Jul 2008 18:06:49 -0400 (EDT), spam_OUTpiclistTakeThisOuTspamian.org said:
> It's worse than just having various types of units.
>
> You also have to define how you measure it.  Your MPG will vary bases on
> how fast you are driving.  And if you have to speed up and slow down. Or
> stop.  Or idle.  Or go up and down a hill.

I think that part is generally understood.

But you didn't say where you live or what units you use.

> The US recently changed how they calculate city milage, and suddenly all
> the cars now get worse city fuel economy.  Well the stated numbers go
> down, the actual economy (or lack of it) has not changed.

There's a calculator(you can look at the source of the web page to see
the formula) to switch between the two, and also a link to the
measurement methods:

http://www.fueleconomy.gov/feg/ratings2008.shtml

Cheerful regards,

Bob

--
http://www.fastmail.fm - Or how I learned to stop worrying and
                         love email again

2008\07\09@182521 by Tomás Ó hÉilidhe

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I'm from Ireland, and we're neither fully metric nor fully imperial
here. For the most part we tend to be metric, but you'll hear imperial
measurements, especially for measuring distances in miles, a person's
weight in stones, and a person's height in feet.

Strangely enough we use "miles per gallon" over here, even though very
few people here know what a gallon is.

I myself tend to talk about how many miles I get for a tenner (i.e.
tenner = 10 Euro), which has dropped lately because of increased fuel
cost. My Toyota Starlet gets me 69.7 miles for a tenner, while my
Peugeot 205 gets 47.

If you wanted to be SI about it then go for "metres per cubic metre" :-D

One thing about volume:  I know at least one person who tries to buy his
petrol in the morning rather than later in the day because when it's
cooler it's denser, so you get more mass for the same amount of money.
As for how denser it is, I don't know.

For me, I make sure I get more fuel by stretching out the fuel tube so
that I don't leave the petrol station with the tube still full of petrol.


.....piclistKILLspamspam@spam@ian.org wrote:
{Quote hidden}

2008\07\09@182614 by Rolf

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Bob Blick wrote:
{Quote hidden}

Canadians typically express in litres/100km.
South Africans typically express in litres/100km too, but also in
km/litre sometimes (at least it was done 10 years or so ago).

Just by the way, in most 'metric' places it is litre, not liter, and the
SI unit is litre as well. You may want to get that right if you are
planning to support international markets... ;-)

Rolf

2008\07\09@191253 by Richard Prosser

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Bob,
Here in NZ litres/100km is the "official" measure, but km/litre is
common, and most of us oldies can still relate to mpg (the gallon
being the imperial variety). (After all we only went metric in 1976).

Richard P

2008/7/10 Rolf <learrspamKILLspamrogers.com>:
{Quote hidden}

> -

2008\07\09@193507 by M. Adam Davis

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On Wed, Jul 9, 2008 at 6:25 PM, Tomás Ó hÉilidhe <.....toeKILLspamspam.....lavabit.com> wrote:
> For me, I make sure I get more fuel by stretching out the fuel tube so
> that I don't leave the petrol station with the tube still full of petrol.

Interesting!  In the US the valve is in the handle (at the end of the
tube) so the fuel stays in the tube once you shut it off (but you got
the fuel from the tube at the beginning, so even though it's measured
at the pump it all evens out)

-Adam

--
EARTH DAY 2008
Tuesday April 22
Save Money * Save Oil * Save Lives * Save the Planet
http://www.driveslowly.org

2008\07\09@193932 by M. Adam Davis

face picon face
Thanks for asking this!  I had asked before but didn't get much
comment.  Now I nee to update my calculator:
http://driveslowly.org/13/mpg-and-savings-calculator

With options for
litres per 100km
litres per km
km per litre
miles per imperial gallon

Although, that nearly fills the problem space.  Need to keep it
simple, but I could make an advanced calculator with two options for
input, and three for output:
Volume units (Gallons, Imperial Gallons, Litres, Hogshead)
Distance units (Miles, KM, Furlongs)
Efficiency Measurement (Volume per distance, distance per volume)
Cost measurement (cost per volume, volume per cost, distance per cost,
cost per distance)

...should take care of the most common permutations, and allow for
simple expansion to add the odd measurements later...

-Adam


On Wed, Jul 9, 2008 at 5:58 PM, Bob Blick <EraseMEbobblickspam_OUTspamTakeThisOuTftml.net> wrote:
{Quote hidden}

> -

2008\07\09@195028 by Bob Blick

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You can probably leave out Irish Miles (6721 feet) and Scottish Miles
(5951 feet) since they were officially put to rest in the year 1592 :)

Cheers,

Bob

P.S. what is a good abbreviation for "metres per 100km"?


On Wed, 9 Jul 2008 19:32:27 -0400, "M. Adam Davis" <stienmanspamspam_OUTgmail.com>
said:
> Thanks for asking this!  I had asked before but didn't get much
> comment.  Now I nee to update my calculator:
> driveslowly.org/13/mpg-and-savings-calculator
>
> With options for
> litres per 100km
> litres per km
> km per litre
> miles per imperial gallon

--
http://www.fastmail.fm - mmm... Fastmail...

2008\07\09@195613 by Bob Blick

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On Wed, 09 Jul 2008 16:50:07 -0700, "Bob Blick" <@spam@bobblickKILLspamspamftml.net>
said:

> P.S. what is a good abbreviation for "metres per 100km"?


I guess the abbreviation for that would be 100000 or maybe 1E5 :)

But what I really wanted to write was "litres per 100km"

oops.

-Bob


--
http://www.fastmail.fm - Access your email from home and the web

2008\07\09@195836 by Richard Prosser

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2008/7/10 Bob Blick <KILLspambobblickKILLspamspamftml.net>:
> You can probably leave out Irish Miles (6721 feet) and Scottish Miles
> (5951 feet) since they were officially put to rest in the year 1592 :)
>
> Cheers,
>
> Bob
>
> P.S. what is a good abbreviation for "metres per 100km"?



10E-5 ??

RP

2008\07\09@200743 by Rolf

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Tomás Ó hÉilidhe wrote:
> One thing about volume:  I know at least one person who tries to buy his
> petrol in the morning rather than later in the day because when it's
> cooler it's denser, so you get more mass for the same amount of money.
> As for how denser it is, I don't know.
>
> For me, I make sure I get more fuel by stretching out the fuel tube so
> that I don't leave the petrol station with the tube still full of petrol.
>  
Apparantly this one has some basis of fact, but more in fiction. Yes,
the colder fuel is more dense, and thus you get more enery density from
the pump, but, it ignores a 'fact' about the ground the petrol station's
tank is buried in (pretty much every fuel station has an underground
storage tank...), and that is that the temperature underground is pretty
constant (for example, in Canada (well, in southern ontario where i have
a little experience with this) we often have geo-thermal house furnaces
that use the ground at about 5feet deep as a heat exchange. The ground
temperature at 5feet deep is about 10 degrees summer or winter - from
+30 in the summer to -30 in the winter). As a result, the fuel you get
in your car is going to be the same temperature regardless of when you
fill up.

The best you can hope for is that (in the summer) the fuel has been in
the tank for a while and cooled down from the deliver truck, and in
winter, it is fresh in the tank from the delivery truck.

More on that here:

http://www.snopes.com/inboxer/household/gastips.asp

and on geothermal heat pumps:

http://en.wikipedia.org/wiki/Geothermal_heat_pump

Rolf

2008\07\09@200933 by Rolf

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Richard Prosser wrote:
> 2008/7/10 Bob Blick <RemoveMEbobblickTakeThisOuTspamftml.net>:
>  
>> You can probably leave out Irish Miles (6721 feet) and Scottish Miles
>> (5951 feet) since they were officially put to rest in the year 1592 :)
>>
>> Cheers,
>>
>> Bob
>>
>> P.S. what is a good abbreviation for "metres per 100km"?
>>    
>
>
>
> 10E-5 ??
>
> RP
>  
Uhm... wouldn;t that be 10e5 not 10e-5?

Rolf

2008\07\09@201400 by olin piclist

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Rolf wrote:
>>> P.S. what is a good abbreviation for "metres per 100km"?
>
> Uhm... wouldn;t that be 10e5 not 10e-5?

Neither.  Try 1e5.

********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000.

2008\07\09@202205 by Tomás Ó hÉilidhe

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Rolf wrote:
>>> P.S. what is a good abbreviation for "metres per 100km"?
>>>    
>>>      
>>
>> 10E-5 ??
>>  
>>    
> Uhm... wouldn;t that be 10e5 not 10e-5?
>  


One metre is:    10 to the power of 0

100 km is:    (10 to the power of 2) multiplied by (10 to the power of
3), which gives a total of 10 to the power of 5

Because it's "per", you divide, so you've got:

   10e0    divided by    10e5

As you know with indices, you add for multiplication, and subtract for
division, so you're left with:

   10e(0-5)

which is:

   10e-5

2008\07\09@202300 by Jinx

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> For me, I make sure I get more fuel by stretching out the fuel tube
> so that I don't leave the petrol station with the tube still full of
petrol

I've heard that described as 'moral theft', because you're stealing off
the next customer

> Yes, the colder fuel is more dense, and thus you get more energy
> density from the pump

ISTR McLaren were investigated in a recent F1 race for having their
fuel bowser at less than regulation temperature

2008\07\09@202600 by Tomás Ó hÉilidhe

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Tomás Ó hÉilidhe wrote:
> Because it's "per", you divide, so you've got:
>
>    10e0    divided by    10e5


Crap that should have been:

   1e0    divided by     1e5

or:

  10^0    divided by    10^5

I hate when I make that mistake!


> As you know with indices, you add for multiplication, and subtract for
> division, so you're left with:
>
>    10e(0-5)


Again, should  be:

  1e(0-5)


> which is:
>
>    10e-5


So my final answer is:  1e-5   or   10 ^ -5


2008\07\09@202902 by Tomás Ó hÉilidhe

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Tomás Ó hÉilidhe wrote:
> Because it's "per", you divide, so you've got:
>
>    10e0    divided by    10e5



Oh God I'm wrong again.


1 metre is 10^1, not 10^0.


So if you've got metres per 100 km, then that's  m^1    /   m^5


Then that gives you:   m ^ -4


Hopefully this is the last time I correct myself on this!

2008\07\09@203117 by Tomás Ó hÉilidhe

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Jinx wrote:
>> For me, I make sure I get more fuel by stretching out the fuel tube
>> so that I don't leave the petrol station with the tube still full of
>>    
> petrol
>
> I've heard that described as 'moral theft', because you're stealing off
> the next customer


Well you have to consider that a lot of people do it accidentally as
well when they pull their car up and their petrol cap is on the wrong
side; they have to stretch the tube across their car, making sure that
no petrol gets left in the tube. Admittedly, I pull up to the wrong side
on purpose :-D

2008\07\09@225428 by Rolf

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Olin Lathrop wrote:
> Rolf wrote:
>  
>>>> P.S. what is a good abbreviation for "metres per 100km"?
>>>>        
>> Uhm... wouldn;t that be 10e5 not 10e-5?
>>    
>
> Neither.  Try 1e5.
>
> ********************************************************************
> Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
> (978) 742-9014.  Gold level PIC consultants since 2000.
>  
I guess it goes to show that two wrong exponents don';t make a right....
serves me right for shooting from the hip, just like the parent poster
... ;-)

Rolf

2008\07\10@004021 by Christopher Head

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Tomás Ó hÉilidhe wrote:
[snip]
| Oh God I'm wrong again.
|
|
| 1 metre is 10^1, not 10^0.
|
|
| So if you've got metres per 100 km, then that's  m^1    /   m^5
|
|
| Then that gives you:   m ^ -4
|
|
| Hopefully this is the last time I correct myself on this!
|
|

... and again... the number of metres in one metre is one, and 1 = 10^0,
not 10^1. (10^1 = 10). Also, the answer is 1e5 not 1e-5, because the
question was "how many metres per 100km". The answer to this question is
given by defining a fixed distance, expressing that distance in terms of
both units, then dividing the expressions. I select the fixed distance
to be 100km. There are 100,000 metres in 100km, and one 100km in 100km.
Thus divide 100,000 by 1 and get 100,000, which is 10^5 aka 1e5.

It would clearly be ridiculous to say that the number of metres per
100km is less than one: a metre is smaller than 100km, so clearly there
must be more than one metre in 100km.

Chris
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2008\07\10@044033 by Alan B. Pearce

face picon face
>ISTR McLaren were investigated in a recent F1 race for having
>their fuel bowser at less than regulation temperature

No they were suggesting that Williams had cooled their tank at the last
Brazilian GP, allowing them to fuel their car faster. Nothing came of the
claim though.

It could potentially be done at a GP, as the tanks used to fuel the cars are
exposed portable units, not underground.

2008\07\10@073008 by Gerhard Fiedler

picon face
Rolf wrote:

> Just by the way, in most 'metric' places it is litre, not liter, and the
> SI unit is litre as well.

Are you sure? I think that depends on the language the document you're
reading is written in, and AFAIK there's no "SI language standard".

In Germany the corresponding SI unit is called "Liter" and in Brazil it is
called "litro". AFAIK, both are "correct" (as is "liter" in the US).

To answer the original question: In Germany the only consumption unit in
use is l/100 km ("Liter [not litre] pro hundert Kilometer") and in Brazil
it's km/l ("kilómetros por litro [not litre]").

Gerhard

2008\07\10@075337 by olin piclist

face picon face
Tomás Ó hÉilidhe wrote:
>>>> P.S. what is a good abbreviation for "metres per 100km"?
>
> Because it's "per", you divide, so you've got:
>
>     10e0    divided by    10e5

Geesh folks, this is basic stuff.

Yes the "per" implies division, but you've got it backwards.  "meters per
100Km" means "the number of meters in 100Km", or 100Km / 1m.

Then you are confused about the XXeYY notation.  As far as I know, this came
from early attempts to express scientific notation in linear text,
specifically in Fortran floating point values.  XXeYY means "XX times ten to
the power of YY", or "XX * 10**YY" (where hopefully it's obvious to everyone
that ** is the exponent operator).  So 10e5 = 10 x 10**5 = 1,000,000, which
is wrong since you were tring to express 100,000.

> which is:
>
>     10e-5

Other than that the 10 should be a 1 and the -5 should be a 5 it's perfect.
The correct answer is 100,000 or 10**5 or 1e5.


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000.

2008\07\10@080041 by Tamas Rudnai

face picon face
Litre is French, isn't it? Or maybe also British English (like Centre vs.
Center - yep, Liter and Center are underlined with red on the British spell
checker). Anyway, for some reason I thought the SI is not Li<something>  :-)
but the equivalent cubic decimeter (ehh, decimetre :-) strange
French/British spellings).

Tamas


On Thu, Jul 10, 2008 at 12:29 PM, Gerhard Fiedler <
spamBeGonelistsspamBeGonespamconnectionbrazil.com> wrote:

{Quote hidden}

>

2008\07\10@080251 by olin piclist

face picon face
Sigh.  This nonsense is getting hard to believe.  Tomas, you earn a big fat
"Duh!", again.

Tomás Ó hÉilidhe wrote:
> Oh God I'm wrong again.
>
> 1 metre is 10^1, not 10^0.

No, it's not.  Check you're 8th grade math.  Any non-zero value to the power
of 0 is 1.  This applies to 10, being as how it's a non-zero value and all.
So 10^0 = 1, 10^1 = 10, 10^2 = 100, do you see the pattern yet?

> Then that gives you:   m ^ -4

This reminds me of the Monty Python skit "Ow, there's a bit of brain lodged
in me 'ead!".

Now you're raising meters to the -4th power.  The units aren't even right by
a factor of the 5th power of length.


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000.

2008\07\10@082138 by Tomás Ó hÉilidhe

picon face

Olin Lathrop wrote:
> Sigh.  This nonsense is getting hard to believe.  Tomas, you earn a big fat
> "Duh!", again.
>  

Count how many people responded with misinformation to my posts about
"integer promotion", and note that I didn't respond in a derogatory
manner to any of them. I didn't call them stupid, I didn't insult them
or ridicule them, I simply corrected them.

Yet, whenever Olin notices a mistake, he feels the need to be rude and
ridiculing, and the moderators accept it.

I think I have every entitlement to say here that the moderation scheme
in place on the Piclist is biased. Can I ask why Olin gets preferential
treatment in the moderation scheme?

2008\07\10@082638 by Rolf

face picon face
Gerhard Fiedler wrote:
> Rolf wrote:
>
>  
>> Just by the way, in most 'metric' places it is litre, not liter, and the
>> SI unit is litre as well.
>>    
>
> Are you sure? I think that depends on the language the document you're
> reading is written in, and AFAIK there's no "SI language standard".
>
> In Germany the corresponding SI unit is called "Liter" and in Brazil it is
> called "litro". AFAIK, both are "correct" (as is "liter" in the US).
>
> To answer the original question: In Germany the only consumption unit in
> use is l/100 km ("Liter [not litre] pro hundert Kilometer") and in Brazil
> it's km/l ("kilómetros por litro [not litre]").
>
> Gerhard
>
>  
Well, looking in to it further, litre is not even a base SI unit, which
is of course cubic meters m³. But, Wikipedia has an interesting article:
http://en.wikipedia.org/wiki/Litre

and also references the differences in spelling:
http://en.wikipedia.org/wiki/American_and_British_English_spelling_differences#-re.2C_-er

Interesting that the unit should normally be abbreviated as 'l', but
that is too much like '1', so, to avoid confusion it is symbolized with
'L', which is contrary to the 'norm' of only using upper-case symbols if
they abbreviate a person's name (like K for Kelvin).

In all, it seems to be a localization thing with mixed effectiveness.
For example, in Canada, I believe the (English) unit will be spelled
litre officially, but, because most of us have US-based spell checkers,
a good portion of us will be confounded by that and prefer liter. By way
of example, the 'officail' fuel consumption guide for 2008 in Canada is
here (4.8meg download):

http://www.oee.nrcan.gc.ca/transportation/tools/fuelratings/fuel-consumption-guide-2008.pdf

This clearly is a 'reference' work for Canadian consumers, and it has
the following info that Bob will/may find interesting:
the units are expressed as L/100km, and the spelling 'litre' is used
throughout. This 'conforms' with my understanding of both British and
Canadian usage of Litre.

Then you also have sites like CTV.ca (canadian news site) which has
mixed messages:
The following (incorrectly) uses liter:
http://toronto.ctv.ca/servlet/an/local/CTVNews/20080708/oil_dollar_080708/20080708/?hub=TorontoNewHome

while the next is interesting because it correctly names the car
'One-Liter' and describes the efficiency as one litre per 100 km
http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20080708/AUTOS_micro_gas_080708/20080708/

So, Canada has a mixed usage because of the US influence.

Rolf

2008\07\10@082859 by Artem Zezyulinskiy

flavicon
face
Not at all. In SI the volume is represented by m3 (cubic metre).
But li(-tre, -ter, -tro, etc) is allowed unit, and it = 1E-3 (m3) cubic
decimetre :)

http://en.wikipedia.org/wiki/SI_derived_unit

**
Tamas Rudnai a écrit :
{Quote hidden}

>>

2008\07\10@085657 by Justin Richards

face picon face
Hi Bob,

In Australian we tend to use l/100km, and my car gets about 11.5l/100km.

As with New Zealand many are happy also quoting in mpg.

Cheers

Justin

On 7/10/08, Artem Zezyulinskiy <RemoveMEartemzezspamTakeThisOuTsedatelec.com> wrote:
{Quote hidden}

>

2008\07\10@090214 by M. Adam Davis

face picon face
On 7/10/08, Rolf <EraseMElearrspamrogers.com> wrote:
> By way of example, the 'officail' fuel consumption guide for 2008 in
> Canada is here (4.8meg download):
>
> http://www.oee.nrcan.gc.ca/transportation/tools/fuelratings/fuel-consumption-guide-2008.pdf

That is really very nice and with a little bit of searching I find
that the US fuel economy database is downloadable:

http://www.fueleconomy.gov/FEG/download.shtml
I wonder if the canadian version is downloadable, and if there's a
unified EU version I can get.

Which is fantastic!  I'll have to add some new features to my website...

<giddy with excitement that will no doubt wear off once I actually
start trying to work with the data>

You can do searches for cars based on model/year, fuel economy, class,
etc from their website:
http://www.fueleconomy.gov/feg/findacar.htm

-Adam

--
EARTH DAY 2008
Tuesday April 22
Save Money * Save Oil * Save Lives * Save the Planet
http://www.driveslowly.org

2008\07\10@091232 by Tamas Rudnai

face picon face
In the other thread there was the Google Calc mentioned, so:
*11.5 l/100km = 20.453442 miles per gallon
**11.5 l/100km = 8.69565217 kilometers / l*
www.google.ie/search?hl=en&q=11.5l%2F100km+in+mpg&btnG=Google+Search&meta=
http://www.google.ie/search?hl=en&q=11.5l%2F100km+in+km%2Fl&btnG=Search&meta=

In case if anyone wonders.. :-)

Tamas


On Thu, Jul 10, 2008 at 1:56 PM, Justin Richards <RemoveMEjustin.richardsEraseMEspamEraseMEgmail.com>
wrote:

{Quote hidden}

> > --

2008\07\10@095506 by Michael Rigby-Jones

picon face

> On Wed, Jul 9, 2008 at 6:25 PM, Tomás Ó hÉilidhe <EraseMEtoespamspamspamBeGonelavabit.com> wrote:
> > For me, I make sure I get more fuel by stretching out the fuel tube so
> > that I don't leave the petrol station with the tube still full of petrol.

> {Original Message removed}

2008\07\10@101456 by Sean Breheny

face picon face
How does the valve at the end of the tube "know" whether the pump is
still feeding gas? It would seem to me that one could just hold the
handle at the nozzle end and keep the valve open.

Sean


On Thu, Jul 10, 2008 at 9:54 AM, Michael Rigby-Jones
<RemoveMEMichael.Rigby-JonesKILLspamspambookham.com> wrote:
>
>> On Wed, Jul 9, 2008 at 6:25 PM, Tomás Ó hÉilidhe <toeSTOPspamspamspam_OUTlavabit.com> wrote:
>> > For me, I make sure I get more fuel by stretching out the fuel tube so
>> > that I don't leave the petrol station with the tube still full of petrol.
>
>> {Original Message removed}

2008\07\10@104251 by olin piclist

face picon face
Sean Breheny wrote:
> How does the valve at the end of the tube "know" whether the pump is
> still feeding gas?

It doesn't.  The pump supplies a roughly constant pressure, and the valve at
the nozzle either lets gas thru or it doesn't.  The flow is measure and
accumulated in the pump.  There is a sensor in the nozzle that can tell when
liquid gets to its level and shut the nozzle off to prevent overfilling and
spilling.

This system makes a lot of sense.  Is it really different in Ireland or is
Tomas just confused?


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000.

2008\07\10@105131 by Michael Rigby-Jones

picon face


> -----Original Message-----
> From: spamBeGonepiclist-bouncesSTOPspamspamEraseMEmit.edu [KILLspampiclist-bouncesspamBeGonespammit.edu] On
Behalf
> Of Olin Lathrop
> Sent: 10 July 2008 15:45
> To: Microcontroller discussion list - Public.
> Subject: Re: [EE] Fuel economy measurement across the globe
>
> Sean Breheny wrote:
> > How does the valve at the end of the tube "know" whether the pump is
> > still feeding gas?
>
> It doesn't.  The pump supplies a roughly constant pressure, and the
valve
> at
> the nozzle either lets gas thru or it doesn't.  The flow is measure
and
> accumulated in the pump.  There is a sensor in the nozzle that can
tell
> when
> liquid gets to its level and shut the nozzle off to prevent
overfilling
> and
> spilling.
>
> This system makes a lot of sense.  Is it really different in Ireland
or is
> Tomas just confused?

I can't speak for Ireland, but every pump I have used in GB is as you
describe.

Regards

Mike

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2008\07\10@113519 by Carl Denk

flavicon
face
No, there is a small tube within the nozzle/valve assembly larger tube
that goes in the vehicle fill point. The vehicle fill point is
restricted, where the only legal nozzle (and there are exceptions) like
unleaded gasoline fits snuggly. When the tank is full and fuel backs up
(usually momentarily until air burps out), the smaller tube experiences
a sudden pressure change. The smaller tube is connected to a pressure
diaphragm which exerts force on the latch, including if hand held open,
and forces the valve which is spring loaded closed to close. This is a
safety device for the automatic fill. Some states do not permit
unattended filling and the automatic latch on the hand valve is missing.
Some vehicle gas caps can be jambed under the hand valve to keep it open
and the auto fill safety will shut the fuel off when fill, well at least
99% of the time. One should always stay very close to the fill point,
but not in line with being a target if fuel suddenly spurts out. Also
mind the static electricity issues.

see:
http://auto.howstuffworks.com/question25.htm
www.petrodirect.com/category.asp?cID=10&sort=T&VIEWALL=TRUE
http://www.opw-fc.com/product_category.aspx?cid=7

Sean Breheny wrote:
{Quote hidden}

>>> {Original Message removed}

2008\07\10@114748 by Nicola Perotto

picon face
In italy they use km/l or l/100 km, witchever sound best at the moment :-((
But the real problem is that the tests are not taken on the road... only
in laboratory!!!

Rolf wrote:
{Quote hidden}

2008\07\10@123419 by Tamas Rudnai

face picon face
> But the real problem is that the tests are not taken on the road... only
> in laboratory!!!

Yes, the actual consumption is dependent on too many things (including
driving skills and style, quality of fuel, actual settings of the engine,
road surface, tyres, air pressure - like if you are in a high mountain -,
temperature, if you are using the car only for short distances, and that
also involves particular extraction on the combustion chamber etc).

Same thing as with the acceleration or the highest speed, calculated numbers
on the 'datasheet' only - these numbers are good indicators though.

Tamas



On Thu, Jul 10, 2008 at 4:45 PM, Nicola Perotto <spamBeGonenicolaspamKILLspamnicolaperotto.it>
wrote:

{Quote hidden}

> -

2008\07\10@155345 by Richard Prosser

picon face
2008/7/11 Tamas Rudnai <.....tamas.rudnaispam_OUTspamgmail.com>:
> In the other thread there was the Google Calc mentioned, so:
> *11.5 l/100km = 20.453442 miles per gallon
> **11.5 l/100km = 8.69565217 kilometers / l*
> www.google.ie/search?hl=en&q=11.5l%2F100km+in+mpg&btnG=Google+Search&meta=
> http://www.google.ie/search?hl=en&q=11.5l%2F100km+in+km%2Fl&btnG=Search&meta=
>
> In case if anyone wonders.. :-)
>
> Tamas

That must be US gallons.
I make that 24.56 mp imperial gallon.

RP

2008\07\10@161246 by Tamas Rudnai

face picon face
> That must be US gallons.
> I make that 24.56 mp imperial gallon.

True - interestingly Google also knows this. Sorry I am just so amazed how
good is this calculator :-)
*11.5 l/100km = 24.5635698 miles per Imperial gallon*
http://www.google.ie/search?hl=en&q=11.5l%2F100km+in+miles+per+imperial+gallon&btnG=Search&meta=

Actually it is so weird to me these exotic measuring systems - gallon but
which, mile but which... Was looking at the different measurements at
Dictionary.com and so funny how many different measure are there for length
for example - and no one are related to decimal number system, many for 12
or 60 or some very exotic ones or is that only cryptic for me?

http://dictionary.reference.com/writing/styleguide/weights.html

Tamas


On Thu, Jul 10, 2008 at 8:53 PM, Richard Prosser <TakeThisOuTrhprosser.....spamTakeThisOuTgmail.com>
wrote:

{Quote hidden}

> -

2008\07\10@161559 by Bob Blick

face
flavicon
face
So far as I can gather, if they are anywhere in the UK, Australia, or
New Zealand, references to gallons are traditionally Imperial.

I have been experimenting with different Googles asking "1 gallon in
litres".

google.ca returns US gallons.

google.co.uk returns Imperial gallons.

google.com.au and google.co.nz return US gallons, seemingly a
contradiction to local custom.

It seems like a good reason to go all-metric :)

Cheerful regards,

Bob



On Fri, 11 Jul 2008 07:53:26 +1200, "Richard Prosser"
<.....rhprosserspamRemoveMEgmail.com> said:
{Quote hidden}

--
http://www.fastmail.fm - Send your email first class

2008\07\10@162554 by Tamas Rudnai

face picon face
Interesting observation. The Irish may hate the British Empire or not sure
the reason but google.ie seems returning US gallons...

Tamas




On Thu, Jul 10, 2008 at 9:15 PM, Bob Blick <spamBeGonebobblick@spam@spamspam_OUTftml.net> wrote:

{Quote hidden}

> -

2008\07\10@162853 by Matt Pobursky

flavicon
face
On 7/10/2008 7:21:09 AM, Tomás Ó hÉilidhe (RemoveMEtoeEraseMEspamspam_OUTlavabit.com) wrote:
> I think I have every entitlement to say here that the moderation scheme
> in place on the Piclist is biased. Can I ask why Olin gets preferential
> treatment in the moderation scheme?

Oh, now THAT'S funny!

Matt Pobursky
Maximum Performance Systems

2008\07\10@163301 by Richard Prosser

picon face
2008/7/11 Bob Blick <@spam@bobblickRemoveMEspamEraseMEftml.net>:
{Quote hidden}

That's Ok by me Bob. I was afraid that the conversion discussion would
denegrate to the "Furlongs per Hogshead" level anyway!

Interesting that the local google converter   assumes US gallons. I
wonder who we contact to get it changed - or at least make it clear
which gallon is being used.

RP

2008\07\10@163351 by Herbert Graf

flavicon
face
On Thu, 2008-07-10 at 13:15 -0700, Bob Blick wrote:
> So far as I can gather, if they are anywhere in the UK, Australia, or
> New Zealand, references to gallons are traditionally Imperial.
>
> I have been experimenting with different Googles asking "1 gallon in
> litres".
>
> google.ca returns US gallons.

See, and this to me is the reason I so dislike gallons. Whenever the
word "gallon" is used in Canada there is an ambiguity, is it the US
gallon or the imperial (British) gallon? Officially Canada is of course
metric, but gallon is still used from time to time, and there is always
confusion as to which gallon is referenced.

Another completely off topic, but REALLY annoying ambiguity is date
formats. Officially in Canada one permitted format is dd/mm/yyyy.
Unfortunately many people/companies use the American format which is
mm/dd/yyyy. So anytime I'm looking at a date in that format, and the day
field is <=12 I have no clue which one it is. Usually I have to find
another time that entity specified a date and hope it's a case where the
dd field is above 12. Very annoying, and I'm sure alot of errors have
happened because of it.

TTYL

2008\07\10@165433 by M. Adam Davis

face picon face
In theory the american format is mm/dd/yy while the EU format is dd-mm-yy.

Unfortunately many people use the wrong delimiter.

Personally I prefer dd-mmm-yy where mmm is the three letter
abreviation, as in 10-JUL-08.  No ambiguity there...

-Adam

On 7/10/08, Herbert Graf <EraseMEmailinglist4spam@spam@farcite.net> wrote:
{Quote hidden}

> -

2008\07\10@170505 by Tamas Rudnai

face picon face
In Hungary - and I believe in Japan as well - we use yy/mm/dd format. When
you say 01-02-03 for me sometimes is even more confusing which year are you
talking about, 2001 or 2003? :-)

Tamas




On Thu, Jul 10, 2008 at 9:54 PM, M. Adam Davis <@spam@stienmanspam_OUTspam.....gmail.com> wrote:

{Quote hidden}

2008\07\10@173013 by Rolf

face picon face
Tamas Rudnai wrote:
> In Hungary - and I believe in Japan as well - we use yy/mm/dd format. When
> you say 01-02-03 for me sometimes is even more confusing which year are you
> talking about, 2001 or 2003? :-)
>
> Tamas
>  
Which all boils down to the best format being yyyy/mm/dd with _any_
separator from '/' to nothing....

20080710
2008/07/10
2008-07-10
2008.07.10
2008_07_10

Then, add the time too, and you get...

20080710.172933
etc.

The big bonus is that alphanumeric sorting of such data will also
arrange it chronologically.
No issues with centuries.
No ambiguity.
Can make it part of filenames, URL's, etc.

Rolf

2008\07\10@173442 by Herbert Graf

flavicon
face
On Thu, 2008-07-10 at 17:29 -0400, Rolf wrote:
> Then, add the time too, and you get...
>
> 20080710.172933
> etc.
>
> The big bonus is that alphanumeric sorting of such data will also
> arrange it chronologically.
> No issues with centuries.
> No ambiguity.
> Can make it part of filenames, URL's, etc.

OK Rolf, now you're scaring me, that's exactly the format I use on a
daily basis...

In the words of Chris Griffin: GET OUT OF MY HEAD!!!

:)

TTYL

2008\07\10@174539 by Josh Koffman

face picon face
On Thu, Jul 10, 2008 at 1:33 PM, Herbert Graf <mailinglist4spamBeGonespamfarcite.net> wrote:
> See, and this to me is the reason I so dislike gallons. Whenever the
> word "gallon" is used in Canada there is an ambiguity, is it the US
> gallon or the imperial (British) gallon? Officially Canada is of course
> metric, but gallon is still used from time to time, and there is always
> confusion as to which gallon is referenced.

Agreed agreed agreed. It's also tricky due to our proximity to the US.
Juice and milk come in US gallon containers, not Imperial gallons.

> Another completely off topic, but REALLY annoying ambiguity is date
> formats. Officially in Canada one permitted format is dd/mm/yyyy.
> Unfortunately many people/companies use the American format which is
> mm/dd/yyyy. So anytime I'm looking at a date in that format, and the day
> field is <=12 I have no clue which one it is. Usually I have to find
> another time that entity specified a date and hope it's a case where the
> dd field is above 12. Very annoying, and I'm sure alot of errors have
> happened because of it.

I like to use yyyy/mm/dd when I'm timestamping files. That way they'll
sort correctly (by date) and make things a bit easier. If I'm in a
directory with only one kind of file then I do
yyyy_mm_dd_FileName.Ext. If there are multiple types of files I use
FileName_yyyy_mm_dd.Ext.

I guess not a perfect standard but works for what I'm doing for now.

Josh
--
A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools.
-Douglas Adams

2008\07\10@175957 by Tamas Rudnai

face picon face
> The big bonus is that alphanumeric sorting of such data will also
> arrange it chronologically.

Exactly. That's why we Hungarians were so lucky with the 70s - 80s computers
- we just kept our date and name format natively and used simple sorting
algorithms to get our database sorted :-) -- We use surname first, then
'firstname', but 'firstname' it is a bit confusing in this context. We were
only unlucky with the weird accents we use - not only because have to enter
and display, but also have to sort it right.

Tamas


On Thu, Jul 10, 2008 at 10:29 PM, Rolf <RemoveMElearr@spam@spamspamBeGonerogers.com> wrote:

{Quote hidden}

> -

2008\07\10@182703 by cdb

flavicon
face


:: In Australian we tend to use l/100km, and my car gets about
:: 11.5l/100km.
::
:: As with New Zealand many are happy also quoting in mpg.

I have never quite understood why metric centred fuel measurement uses
the L/100klm formula, to me MPG (imp or US) says - you've travelled so
far and used so much, of course if you used KPL you'd end up with
fractions or some bright spark would think your talking about Key
Perfomance Learnings or some such trash.

Peugeot 307 - 1100klms/tank  tank = 65 litres or if you prefer
5.6L/100Klm.

More diesel pumps in Australia please!

Colin
--
cdb, .....colin@spam@spamEraseMEbtech-online.co.uk on 11/07/2008

Web presence: http://www.btech-online.co.uk  

Hosted by:  http://www.1and1.co.uk/?k_id=7988359

Friendship multiplies the good of life and divides the evil.
Baltasar Gracian





2008\07\10@184157 by Herbert Graf

flavicon
face
On Fri, 2008-07-11 at 08:27 +1000, cdb wrote:
>
> :: In Australian we tend to use l/100km, and my car gets about
> :: 11.5l/100km.
> ::
> :: As with New Zealand many are happy also quoting in mpg.
>
> I have never quite understood why metric centred fuel measurement uses
> the L/100klm formula, to me MPG (imp or US) says - you've travelled so
> far and used so much, of course if you used KPL you'd end up with
> fractions or some bright spark would think your talking about Key
> Perfomance Learnings or some such trash.

I don't know why L/100km exists, but I do prefer it.

The reason is pretty specific to where I am, but here goes:

Since the speed limit in most areas results in people driving around
100km/h on average, that L/100km figure can often be changed to L/hour.

Since most people where I'm from refer to distances in number of hours
needed to get there (i.e. North bay is about 6 hours north of Toronto is
VERY commonly heard), it makes it REAL easy to figure out how much fuel
you need.

6 hours to North Bay, car gets 6L/100km, which is about 6L/hour, so
that's roughly 36L to get there.

This may sound strange to some, but that's how we do things! :)

TTYL

2008\07\10@190712 by Tamas Rudnai

face picon face
Hmm, L/hour, never thought that way, but makes sense when you stuck in the
traffic. Common measurement in airplanes anyway :-)

L/100km is convinient as you have a rough idea how much petrol/diesel you
need to get somewhere. Or maybe as we just got used to it.

Tamas



On Thu, Jul 10, 2008 at 11:41 PM, Herbert Graf <.....mailinglist4RemoveMEspamfarcite.net>
wrote:

{Quote hidden}

> -

2008\07\10@190951 by Gerhard Fiedler

picon face
Herbert Graf wrote:

> Another completely off topic, but REALLY annoying ambiguity is date
> formats. Officially in Canada one permitted format is dd/mm/yyyy.
> Unfortunately many people/companies use the American format which is
> mm/dd/yyyy. So anytime I'm looking at a date in that format, and the day
> field is <=12 I have no clue which one it is. Usually I have to find
> another time that entity specified a date and hope it's a case where the
> dd field is above 12. Very annoying, and I'm sure alot of errors have
> happened because of it.

2008-05-07 is the one that's least ambiguous. It's always yyyy-mm-dd. I
think there's an ISO standard for it.

Gerhard

2008\07\10@200950 by Tomás Ó hÉilidhe

picon face


M. Adam Davis wrote:
> Personally I prefer dd-mmm-yy where mmm is the three letter
> abreviation, as in 10-JUL-08.  No ambiguity there...

I use 2008-07-11 for today's date because it's language-independent.

2008\07\10@201306 by Tomás Ó hÉilidhe

picon face


Gerhard Fiedler wrote:
> 2008-05-07 is the one that's least ambiguous. It's always yyyy-mm-dd. I
> think there's an ISO standard for it.


And I bet it's 200 pages long :-D

2008\07\10@221619 by Sean Breheny

face picon face
Thanks for the reply, Olin, but I wasn't talking about how the pump
knows to stop pumping. As I understood it, several piclisters were
saying that the valve at the nozzle end normally stays closed to
prevent people from emptying the tube after the pump has shut down. I
was wondering how the valve at the nozzle end "knows" to close after
pumping is finished.  I would have thought that it would open whenever
the handle was squeezed closed.

Sean


On Thu, Jul 10, 2008 at 10:45 AM, Olin Lathrop
<.....olin_piclistSTOPspamspam@spam@embedinc.com> wrote:
{Quote hidden}

> -

2008\07\11@082005 by Gerhard Fiedler

picon face
Tomás Ó hÉilidhe wrote:

> Gerhard Fiedler wrote:
>> 2008-05-07 is the one that's least ambiguous. It's always yyyy-mm-dd. I
>> think there's an ISO standard for it.
>
> And I bet it's 200 pages long :-D

Bet how much? Think you lost... :)

Given the complexity of the issue, the number of different formats and the
many different ways dates are referred to, this standard is not excessive
at all, IMO.

ISO 8601:2004 Data elements and interchange formats -- Information
interchange -- Representation of dates and times

A good summary:
<www.cl.cam.ac.uk/~mgk25/iso-time.html>
Wikipedia, also good:
<http://en.wikipedia.org/wiki/ISO_8601>
More to the point, Wikipedia provides a direct download link for the ISO
document (40 pages):
<http://isotc.iso.org/livelink/livelink/4021199/ISO_8601_2004_E.zip?func=doc.Fetch&nodeid=4021199>

ISO's own summary:
<www.iso.org/iso/date_and_time_format>
Here you can buy it (not sure how this relates to the link published in
Wikipedia):
<http://www.iso.org/iso/catalogue_detail?csnumber=40874>

A short overview of the formats in list form, from an older version of ISO
8601 (1988):
<http://www.hydracen.com/dx/iso8601.htm>

The W3C take on this (they basically adopted a subset of ISO 8601):
<http://www.w3.org/QA/Tips/iso-date>
<http://www.w3.org/TR/NOTE-datetime>

Gerhard

2008\07\11@084611 by olin piclist

face picon face
Sean Breheny wrote:
> Thanks for the reply, Olin, but I wasn't talking about how the pump
> knows to stop pumping. As I understood it, several piclisters were
> saying that the valve at the nozzle end normally stays closed to
> prevent people from emptying the tube after the pump has shut down. I
> was wondering how the valve at the nozzle end "knows" to close after
> pumping is finished.  I would have thought that it would open whenever
> the handle was squeezed closed.

I'm not sure what you're asking as it's not making much sense.

The valve for starting and stopping gas flow when filling your car is in the
nozzle.  This valve is usually activated by a grip that you squeeze.  When
your tank is full this valve shuts off by itself, or you manually release
the grip to shut it off.  If you were to squeeze the grip again, more gas
would flow, but you'd also get charged for that.

The pump senses when you return the nozzle to the holder in the pump and
completes the billing.  On some pumps this is done by swinging a lever which
phisically locks the nozzle in place.  It won't be released until the next
billing has started.  Some pumps shut down the internal pump, but of course
it is turned on again when the nozzle is removed by the next customer.

I'm not really sure what you're asking.  Haven't you ever filled up a car
before?  If not, go with someone next time they do it.  It's really not
complicated, and it's pretty obvious how the system works when you look at
it.


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000.

2008\07\11@092735 by M. Adam Davis

face picon face
On 7/11/08, Olin Lathrop <olin_piclistEraseMEspam@spam@embedinc.com> wrote:
> Some pumps shut down the internal pump, but of course
> it is turned on again when the nozzle is removed by the next customer.

The modern gas stations where I've seen the 'back room' have a
variable frequency drive pump for each storage tank of fuel.  The
pumps feed all the dispensers.  This method is less expensive overall
and easier to stop in case of emergency.  Generally they don't buy a
large enough pump to feed all the dispensers at once, so when lots of
people are fueling you can tell it's fuelling more slowly than usual.
further, some stations buy smaller pumps for the less frequently used
fuels.

The dispensors aren't much more than payment machines with meters (and
ads) and safety equipment...

-Adam

--
EARTH DAY 2008
Tuesday April 22
Save Money * Save Oil * Save Lives * Save the Planet
http://www.driveslowly.org

2008\07\11@103543 by Sean Breheny

face picon face
Hi Olin,

I may be relatively young (28) but I've been driving for 10 years and
certainly have filled up a car before :)

Let me try to rephrase my question by giving an example.

Let's say I go to fill up. First, I slide my credit card and select
the type of gas I want. Then I remove the nozzle and place it into the
filler tube in the car. Next I squeeze the handle and the pump starts
pumping fuel.

When the tank fills and the nozzle detects gas next to the small holes
on the outside of the nozzle, it closes the valve at the nozzle and
the gas stops flowing. I could "top it off" by continuing to cycle the
handle through open and closed.

Now, I put the nozzle back into the holder on the pump and complete
the transaction. At this point, the entire tube from the pump to the
nozzle is still full of gas, right?

Now if I remove the nozzle from the holder again, without swiping my
card again, and then squeeze the handle, how come I don't get the
contents of the tube spilling out? Sure, the pump will not deliver
more gas into the tube, but I would think that the gas inside the tube
could still come out.

I can only think of a few ways this could be prevented:

1) suck the fuel back out of the tube into the pump
2) somehow enable the pump to signal the valve at the nozzle to remain
closed when there isn't an active transaction going on.
3) Have the entire connection from pump through to nozzle be so air
tight that no air could get back in to displace the gasoline so that
it will not come out unless the pump is pumping (I'm having trouble
trying to determine whether this would work as it seems that normally
even a tube which is sealed at one end and filled with liquid can
still be emptied from the other end).
4) have the valve at the nozzle end require a minimum pressure to open
(which is greater than the pressure developed by gravity on the
vertical height of gasoline in the tube)

My question is which of these is done (or what possibility did I not consider)

Thanks,

Sean


On Fri, Jul 11, 2008 at 8:48 AM, Olin Lathrop <RemoveMEolin_piclistspamspamBeGoneembedinc.com> wrote:
{Quote hidden}

> -

2008\07\11@105657 by Carl Denk
flavicon
face
In the USA, the EPA mandates certain spill prevention and leak detection
methods. One of these is, if the nozzle valve is open when the pump
starts ( or manifold valve in the case of many dispensers on one pump).
The unrestricted hose end will be interpreted as a broken hose leaking
and the mechanical (no electrical required) leak detector before the
dispenser hose will shut the flow off to a trickle. Reseting requires
fixing the leak (close the nozzle valve) and shutting off the source
(pump usually) briefly.

Here is a good description of the entire fuel dispensing system, above
described is "MLD"
http://www.acetank.com/Public/Solutions/ServiceStations/index.cfm?requesttimeout=100

Sean Breheny wrote:
{Quote hidden}

>> --

2008\07\11@120304 by olin piclist

face picon face
Sean Breheny wrote:
> Let's say I go to fill up. First, I slide my credit card and select
> the type of gas I want. Then I remove the nozzle and place it into the
> filler tube in the car. Next I squeeze the handle and the pump starts
> pumping fuel.
>
> When the tank fills and the nozzle detects gas next to the small holes
> on the outside of the nozzle, it closes the valve at the nozzle and
> the gas stops flowing. I could "top it off" by continuing to cycle the
> handle through open and closed.
>
> Now, I put the nozzle back into the holder on the pump and complete
> the transaction. At this point, the entire tube from the pump to the
> nozzle is still full of gas, right?
>
> Now if I remove the nozzle from the holder again, without swiping my
> card again, and then squeeze the handle, how come I don't get the
> contents of the tube spilling out? Sure, the pump will not deliver
> more gas into the tube, but I would think that the gas inside the tube
> could still come out.

It may be that even with a wide open valve that air can't get back up into
the hose to displace the gas.  There must be some elasticity in the hose and
you probably would get a little extra gas.

In any case, it would be fraud to try to take more gas from the pump after
you indicated you were done by placing the nozzle back into the holder.  If
you could get a meaningful amount of gas this way and there were enough
dirtbags that did this, there would be measures to prevent it.

This is all rather different from what Tomas was talking about.  Can someone
from Ireland comment of whether the system really is different over there,
or did Tomas just get confused in the excitement of thinking he was getting
something for nothing?


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000.

2008\07\11@124620 by Walter Banks

picon face
{Quote hidden}

In my mis-spent youth at 2am I remember being about 40 miles from
home and out of gas in a small town whose gas stations had long since
closed

We drained the hoses from a couple gas stations and got enough to get
home. This was back in the days when hoses were never locked to the
pumps.

w..

2008\07\11@133235 by M. Adam Davis

face picon face
Consulting the Oracle (google) we find this example:

http://www.opw-fc.com/product_category.aspx?cid=7

apparently some fuel nozzles (pump handles to us, fuel nozzle to the
industry) do allow one to dispense product from an unpressurized hose.

There are fuel nozzles, however, that will not dispense product until
the line is under pressure, preventing this sort of theft.  These
pressure sensitive nozzles are marketed more as spill and 'loss'
prevention.

-Adam

On 7/11/08, Sean Breheny <shb7spam_OUTspam@spam@cornell.edu> wrote:
{Quote hidden}

2008\07\11@190458 by cdb

flavicon
face
:: As I understood it, several piclisters were
:::: saying that the valve at the nozzle end normally stays closed to
:::: prevent people from emptying the tube after the pump has shut
:::: down. I
:::: was wondering how the valve at the nozzle end "knows" to close
:::: after
:::: pumping is finished.  I would have thought that it would open
:::: whenever
:::: the handle was squeezed closed.

Is there a syphoning effect happening at the pump when it is switched
off?  One of the reasons why some pumps seem to have a lag between
squeezing the trigger, fuel being dispensed (and annoyingly the meter
whizzes around before fuel has started to flow) is due to the fuel
station not priming it's pumps properly and leaking pump seals. So it
maybe that the hose is empty if the fuel is 'sucked' back into the
pump, though the primed pump should expel the air quickly when the
next user switches the pump back on.

( a fuel stations manager's trick to skim some extra money is not to
prime the pumps each day, the fuel dispensed that is registered, but
actually hasn't flowed, may be smallish, but over the course of a
day's trade, amounts to 100% profit.)

Colin
--
cdb, RemoveMEcolinEraseMEspamKILLspambtech-online.co.uk on 12/07/2008

Web presence: http://www.btech-online.co.uk  

Hosted by:  http://www.1and1.co.uk/?k_id=7988359








2008\07\11@195814 by Carl Denk

flavicon
face
The pumps are all submersible, and have a check valve after the pump
turbines (very close, the entire pump including motor, turbine and check
valve, probably less than 2 feet long). The entire system is liquid(and
for all practical purposes air too) tight, When the pump is turned on
for the first time (new, after maintenance or running the tank dry)
after being immersed in fuel, it will  self prime very quickly and the
air will get compressed in the piping, dispenser, and hose to the
nozzle. Opening the nozzle valve will allow the air to be expelled from
the system. Once this is done (should be done by the system operator,
and not customer) there should not be any air in the system, though it
would be possible to drain the liquid in the hose by turning off the
pump (read as including a manifold valve if multi dispenser system) and
opening the nozzle valve with the nozzle lower than it's attachment to
the dispenser. Most meters I have seen only measure liquid, and not air,
but this may not be always true. Older dispensers (1950's) had a glass
sight glass with a little turbine in it to verify there was flow, and no
air.

The nozzle valve is a spring loaded normally closed valve, otherwise,
when the pump is turned on there would be flow, which would not be safe
big time. The nozzle valve closes for 2 reasons: 1: Stop squeezing the
lever. 2: A full vehicle tank condition is sensed, and the valve is
closed automatically, no matter what is keeping the valve open, either a
hand, the auto fill latch, or a gas cap or something jambed under the
hand lever.

Stretching the hose might yield a fluid ounce or so, I don't consider it
worth my time. Draining the hose, is cheating the next customer since he
is going to get charged for it.

One item hasn't been discussed, vapor recovery. As a tank gets filled,
fuel vapors are displaced by fresh liquid. Conversely, as a tank is
emptied, fresh air is drawn in, unless there is another hose to allow
the vapors to transfer from the filled tank to the emptied tank. For
vehicle filling, there is a neoprene (usually black) accordion boot on
the tube that goes in the vehicle fill point sealing the area, and the
vapors leave the nozzle in a coaxial hose (it will be large diameter
than usual). For tank truck delivery, there is a separate hose the truck
drive must connect to return the vapors to the transport tank. Upon
return to the distribution terminal where we will assume the fuel is
delivered via a pipe line from some distant point, the fuel vapors are
condensed back to product. I have been told this could result in 5
gallons recovered from a 8000 gallon transport.

cdb wrote:
{Quote hidden}

2008\07\11@203507 by olin piclist

face picon face
Carl Denk wrote:
> The pumps are all submersible, and have a check valve after the pump
> turbines (very close, the entire pump including motor, turbine and check
> valve, probably less than 2 feet long). The entire system is liquid(and
> for all practical purposes air too) tight, When the pump is turned on
> for the first time (new, after maintenance or running the tank dry)
> after being immersed in fuel, it will  self prime very quickly and the
> air will get compressed in the piping, dispenser, and hose to the
> nozzle. Opening the nozzle valve will allow the air to be expelled from
> the system. Once this is done (should be done by the system operator,
> and not customer) there should not be any air in the system, though it
> would be possible to drain the liquid in the hose by turning off the
> pump (read as including a manifold valve if multi dispenser system) and
> opening the nozzle valve with the nozzle lower than it's attachment to
> the dispenser. Most meters I have seen only measure liquid, and not air,
> but this may not be always true.

This is generally how all pumps work I've seen in recent decades, but things
were not always so.  Back when I was in grade school we were driving thru
northern Arizona and New Mexico, and happened to need gas in the Hopi indian
reservation.  We had ask around a bit for where there was a gas station, but
eventually we were directed to a town on the top of a hill a few miles from
the main road.  The gas pump had a big upside down jar on top, looking
sortof like one of those replacable water jugs of office water coolers.
Except this jar was a bit bigger, glass, and on top of the pump at eye
level.  The gas station attendent asked how much gas we wanted, then worked
a mechanical pump by hand that caused the big glass jar to fill up.  It was
marked off in gallons.  Once he got to the gallons we requested, he stopped
pumping and the car was filled by gravity from the big jar.  Pretty cool.  I
vaguely remember gas cost in the low 30 cents per gallon range.

The cheapest gas I remember was in the middle of noplace Nevada (maybe Utah
or Arizona).  It was at a crossroads of two paved roads with a gas station
on 3 of the 4 corners with pretty much nothing else around for 10s of miles.
The gas price was 18 cents/gallon, which was a great deal even then.


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000.

2008\07\11@205549 by Carl Denk

flavicon
face
Yep, that was the equipment used in the 30's and 40's. By the 50's they
were all gone except for a few isolated instances. Today, they are
museum pieces. The neat thing of those devices, was, you could see the
fuel color and the quantity you were getting. Today we rely on the
electronics and we all know how good and how that can be hacked. In
Ohio, most states are similar, the county auditor has people that go
around with calibrated containers, and check the accuracy of the meters.
The dispenser if good, gets a dated seal sticker that is good for a
year. Some states check the quality of the fuel for purity and octane
rating, Ohio does not!

Last week, I picked up 40 gallons of off road (no highway tax) diesel
fuel for our tractor at the local distributor that services farmers and
businesses. I pumped from a 3000 gallon above the ground tank with a
pump/meter unit mounted on top. This was the exception to the
submersible tank setup. The nozzle tube was at least 1" diameter, no way
could you get it into a car fill point. :)

Olin Lathrop wrote:
{Quote hidden}

2008\07\12@014828 by Nate Duehr

face
flavicon
face

On Jul 10, 2008, at 6:12 PM, Tomás Ó hÉilidhe wrote:

>
>
> Gerhard Fiedler wrote:
>> 2008-05-07 is the one that's least ambiguous. It's always yyyy-mm-
>> dd. I
>> think there's an ISO standard for it.
>
>
> And I bet it's 200 pages long :-D



And if you're really unlucky, instead of using ISO standards, you have  
to live in the telecom world where the ITU is the place to go.  ITU  
standards will often have an Annex -- an add-on that changes the  
standard completely.

And if it's from ITU it costs big money to get a "real" copy.  And  
upon receiving it and reading it you find that it describes six  
different ways to do the same thing, therefore doesn't "define" a  
standard at all.

Start with ITU H.320, compare to H.323 -- one's ISDN, the other IP --  
but after that they're the same.  Then try to find all of the  
appropriate videoconferencing standards underneath H.323.  Then  
realize that you're looking for an audio answer and the overlying  
standard just calls out other standards, in this case... it's actually  
G.729.1 Annex C that you're REALLY trying to find.

And shake your head when you realize that G.729.1 and G.729.1 Annex C  
aren't even using the same technology or CODEC, but ended up the same  
number because G.729 was "extensible".

Did the above just this week... because some $20 software client said  
it did G.729.1 and the customer thought that meant it would do G.729.1  
Annex C.

And we pay for the privilege of having copies of this slop. :-)

--
Nate Duehr
.....natespamRemoveMEnatetech.com



2008\07\12@022217 by Nate Duehr

face
flavicon
face

On Jul 11, 2008, at 6:55 PM, Carl Denk wrote:

> Last week, I picked up 40 gallons of off road (no highway tax) diesel
> fuel for our tractor at the local distributor that services farmers  
> and
> businesses. I pumped from a 3000 gallon above the ground tank with a
> pump/meter unit mounted on top. This was the exception to the
> submersible tank setup. The nozzle tube was at least 1" diameter, no  
> way
> could you get it into a car fill point. :)


If it was the "standard" larger diesel nozzle size used by 18-
wheelers, the Volkswagen diesel cars not only can handle the larger  
diameter nozzle, but also have a special air return system (a valve  
activated by the larger nozzle being inserted opens an air "escape"  
valve that allows air to escape at a much faster rate from the fuel  
tank up through a tube to that plastic valve in the filler port.

This allows you to fill up at the much bigger nozzle pumps the trucks  
use at a horrendously fast rate.  But you'd better watch it closely  
because it'll easily overfill and cause a spill at those pumps.

You have to love VW engineers for including it, though.

Since this air return system also incorporates a small pocket of air  
molded into the top of the fuel tank, many VW diesel drivers will  
carry a few disposable latex gloves or similar and on long trips where  
they want the maximum fuel in the tank during a fill-up, they'll reach  
in with a finger and push the air valve open while using a regular  
"car sized" small diesel nozzle, which will allow for "topping off"  
the tank with quite a bit more fuel into that "air space" at the top.

It's a pretty significant amount of fuel, but I don't remember how  
much.  I didn't have gloves with me the day I messed with it on my  
wife's Jetta Wagon, and I smelled like diesel for the rest of the day,  
even with trying to wash it off... gloves highly recommended.  :-)

Meanwhile the thing's highway fuel economy is so high, that even if I  
watch my water and/or coffee intake when on a long road trip, the  
diesel car will always outlast my bladder -- "extra fillup" or a  
regular one.   One tank of fuel from just south of Mt. Rushmore, South  
Dakota to the south suburbs of Denver, CO is WAY too long to be in the  
driver's seat... I didn't even attempt it.  But I didn't have to fill  
up...

Not particularly interested in finding out what Deep Vein Thrombosis  
and pulmonary edema from a blood clot passing through my heart is like.

Only really messed with filling the car with the larger "truck" pumps  
once.  It was full so fast, it was amazing, even only opening the pump  
to the first "notch" on the locking mechanism.  WHOOOOSH.  Nice if you  
had to, but not really worth the nervousness that goes with it.

--
Nate Duehr
natespam@spam@natetech.com



2008\07\12@081730 by Carl Denk

flavicon
face
Agreed. I should of said, that the object of different size nozzles and
restrictions is to prevent using an improper fuel, either intentionally
or not, and the diesel nozzle won't fit in a gasoline either with or
without lead fill point. I was fueling a 1979 Ford Bronco (full size
SUV) in Helana Montana.THe vehicle required unleaded fuel since it had a
catalytic converter. I selected  gasohol dispenser, not reading that it
was not unleaded. The nozzle wouldn't fit, and then I read the label and
had to switch dispensers. Along the same lines, the off the road fuel is
dyed bright red! I have been told the red will persist in your tank for
a long time, and the fine for road use can be substantial, in the $1000's.

Our standby electric generator for the house backup fuel is highway use
gasoline. The 175 gallon tank is used mainly for road vehicles.

Most small aircraft can be fueled either gasoline or jet fuel since the
fill point is usually large enough. The fill point is required to be
labeled type fuel and capacity, but a plane crashing from wrong fuel is
not unusual :( Some are caused by the transport delivery driver filling
the wrong tank, or a mix up at refinery or terminal! The fuels are
different color and it is the pilots responsibility to check the color
and presence of water or other containments after fueling and before flight.

Nate Duehr wrote:
{Quote hidden}


'[EE] Fuel economy measurement across the globe'
2008\08\17@073745 by Dario Greggio
face picon face
for the records, it's "litro" in Italy, and "litri / 100Km" or "Km /
litro" in here :)

--
Ciao, Dario -- ADPM Synthesis sas -- http://www.adpm.tk

2008\08\17@171809 by Dario Greggio

face picon face
Olin Lathrop wrote:

> or did Tomas just get confused in the excitement of thinking he was getting
> something for nothing?

In Italy, tales are reported that, back in the 80s, you could jump over
the pipe and get some more fuel: urban myths also tell that you could
fill a scooter's tank doing that on some 4-5 pumps...


--
Ciao, Dario

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