On Sunday, November 9, 2014 12:12:06 PM UTC-5, SMS wrote:
On 11/8/2014 11:27 AM, rbowman wrote:
wrote:

So all "discernable advantages" should be paid for by someone else
and provided to you for free?? Sounds a little bitopportunistic anda
lot like a bad case of "entitlement"

I won't mention politics but SMS's view that he is fully capable of
maintaining the pressure in his tires by checking it with a tire gauge but
the general populace is not and should be provided with a free benefit to
save themselves from themselves has a familiar ring to it.

You're not looking at the big picture. It's often not saving
_themselves_ from themselves, it's saving _us_ from _them_. If they have
a blowout and cause an accident, others are often involved. And do you
check the tire pressure of every vehicle that you or members of your
family get into?


And of course you have some data that shows nitrogen prevents blowouts,
right?




There are many instances of society imposing non-free requirements for
the common good. What ends up happening is the cost of those
requirements ends up to be fairly trivial once volumes go way up.


OMG, now you're suggesting mandating nitrogen. Good example of why
California is so screwed up.



If you recall the history of TPMS, it became mandatory in the U.S. in
2007 following the Firestone Tire tread separation issue which was
linked to more than 100 deaths. The tread separation was greatly
exacerbated by under-inflation. The cost of TPMS far exceeds the cost of
nitrogen for a vehicle's tires. A vehicle may go through 24 tires at a
cost of maybe 10¢/tire for nitrogen. But a TPMS system adds about $25 in
manufacturing cost to a vehicle.


But a TPMS system at least goes well beyond the minimal difference nitrogen
makes. If you pick up a nail and the tire is rapidly loosing air, TPMS
will tell you. The nitrogen will leak out about 5 secs slower than plain
air.


The government should not also require nitrogen, but it would be
extremely foolish for anyone to buy tires from a store that did not
inflate all the tires they sell with nitrogen.

How about mandating that all cars be painted bright neon yellow. It's just common sense that bright colors reduce accidents, save lives. OMG, won't somebody please think of the children! Only a fool would buy a car without
it being neon yellow.

On Sunday, November 9, 2014 1:31:44 PM UTC-5, dpb wrote:
On 11/09/2014 11:16 AM, SMS wrote:
On 11/8/2014 1:10 PM, dpb wrote:
On 11/07/2014 9:58 AM, SMS wrote:
...

Not true. There is a discernible advantage, but not one that is worth
paying anything extra for. Just never buy tires at a retailer that does
not include nitrogen inflation at no extra charge.

Don't fool yourself that you're not paying for it -- it may not be
itemized, but trust me, it's in there...

You don't understand how retailers set prices. It's not based on fixed
percentage over their costs, it's based on the market.
..

Trust me, however they build their advertising cost structure, the cost
of the product and services _IS_ in there. You're not getting anything
"free", you just don't know where it is in the final check.

It's like the colleague of mine years ago who had some specific expenses
rejected on an expense account for work travel. The next submittal
totalled the same net amount but the items in question were nowhere to
be seen. Same thing here.

The reason Costco just includes nitrogen is that it makes good business
sense. It reduces their costs by reducing warranty returns for both
treadwear and road hazard.

Now you're back to what you promised not to do any more without specific
evidence.

--



Here's what one respected auto authority has to say on the subject:

http://www.edmunds.com/car-care/shou...-nitrogen.html

The Green Cap on Your Tire Could Take Green From Your Wallet

http://www.edmunds.com/car-care/shou...-nitrogen.html

Based on cost, convenience and actual performance benefit, we don't think nitrogen is worth it. A much better use of your money would be to buy a good tire-pressure gauge and check your tires frequently.

And Consumer Reports did a test:

http://www.consumerreports.org/cro/n...tudy/index.htm

"The test started on September 20, 2006 and the final measurements were taken on September 20, 2007. The results show nitrogen does reduce pressure loss over time, but the reduction is only a 1.3 psi difference from air-filled tires. The average loss of air-filled tires was just 3.5 psi from the initial 30pressure setting. Nitrogen-filled tires lost an average of 2.2 psi from the initial 30 psi setting.


Bottom line: Overall, consumers can use nitrogen and might enjoy the slight improvement in air retention provided, but it's not a substitute for regular inflation checks."


Now at least that is some real data. Over a year, ~ 1 PSI difference in
pressure. And that was with CR purging the tires 3 times to get all the
air out before the final nitrogen filling. And that is supposed to
translate to less warranty claims at Costco? Less blowouts? Less carnage
on the roads? Give me a break.

On Sunday, November 9, 2014 6:35:04 PM UTC-5, SMS wrote:
On 11/9/2014 10:31 AM, dpb wrote:
On 11/09/2014 11:16 AM, SMS wrote:
On 11/8/2014 1:10 PM, dpb wrote:
On 11/07/2014 9:58 AM, SMS wrote:
...

Not true. There is a discernible advantage, but not one that is worth
paying anything extra for. Just never buy tires at a retailer that does
not include nitrogen inflation at no extra charge.

Don't fool yourself that you're not paying for it -- it may not be
itemized, but trust me, it's in there...

You don't understand how retailers set prices. It's not based on fixed
percentage over their costs, it's based on the market.
..

Trust me, however they build their advertising cost structure, the cost
of the product and services _IS_ in there. You're not getting anything
"free", you just don't know where it is in the final check.

It is not free. It is included. But the price would not go down if it
was not included. That is the key thing to understand. Companies set
prices based on the market, not how much it costs them to manufacture a
product or provide a service.

You really need to take a course in economics 101. Yes, companies set their
prices based on market demand. But what you're suggesting is that if a product
is changed to leave things out, that it will not have an effect on the demand
curve for that product. Obviously there are people who believe nitrogen is valuable and if it's not in a tire they buy, they will pay less, go somewhere else, etc. That shifts the demand curve which is what then lowers the market price for a tire without it.

On 11/10/2014 2:59 AM, SMS wrote:
On 11/9/2014 6:00 PM, dpb wrote:
On 11/09/2014 5:34 PM, SMS wrote:
...

It is not free. It is included. But the price would not go down if it
was not included. That is the key thing to understand. Companies set
prices based on the market, not how much it costs them to manufacture a
product or provide a service. U.S. automakers would all be gone if they
tried to price their vehicles based on the cost of parts and labor and
then marking it up the same percentage as Toyota or Honda.
...

Nonsense on the latter; whether they would reduce pricing on the removal
of the amenity/service is a totally different question--more than likely
they'd just take the marginally higher return.

Certainly if the price structure is not reflective of the cost of
producing the product or service they won't last long...

But they do last. The only reason the big 3 were producing small cars
was because of government requirements that their fleet MPG be at a
certain level. They would much rather have produced only high margin,
high profit, low MPG models. They set their small car prices at market
prices, and lost money on them in order to increase the fleet mpg.

Again, can you show actual data backs up that hypothesis? It would
certainly behoove any company to build the high margin, high profit
items over a lesser-producing product; not much to fault them on there.
The government should've stayed out of it imo...

That they have re-emerged as profitable having reworked the ridiculous
overhead costs of the medical and labor contracts pretty much negates
the whole contention, anyway. That was different time, different place...

--

On 11/9/2014 6:00 PM, dpb wrote:
On 11/09/2014 5:34 PM, SMS wrote:
...

...

Certainly if the price structure is not reflective of the cost of
producing the product or service they won't last long...

But they do last. The only reason the big 3 were producing small cars
was because of government requirements that their fleet MPG be at a
certain level. They would much rather have produced only high margin,
high profit, low MPG models. They set their small car prices at market
prices, and lost money on them in order to increase the fleet mpg.

One last comment on your pricing naivete then I'll mark 'Ignore Thread'
before letting this inanity continue further...

Even if they did purposely price a portion of the fleet below cost, (and
I'm certainly not at this point willing to concede that was really so)
it's still the overall cost/revenue for the entire company that's the
significant number. You can think of the loss-leader car as the N throw
away at Costco--it's in their overall cost structure just as the two
bookshelves were in the revised expense account the colleague
resubmitted--it was covered up by using per diem rates instead of
actuals to the point of making up the difference and such. Again, it's
the overall that matters, not each individual piece necessarily.

--

On 11/10/2014 5:58 AM, trader_4 wrote:
....

And Consumer Reports did a test:

http://www.consumerreports.org/cro/news/2007/10/tires-nitrogen-air-loss-study/index.htm

"The test started on September 20, 2006 and the final measurements
were taken on September 20, 2007. The results show nitrogen does
reducepressure loss over time, but the reduction is only a 1.3 psi difference
from air-filled tires. The average loss of air-filled tires was just 3.5
psi from the initial 30pressure setting. Nitrogen-filled tires lost an
average of 2.2 psi from the initial 30 psi setting.


....

Now at least that is some real data. Over a year, ~ 1 PSI difference in
pressure. And that was with CR purging the tires 3 times to get all the
air out before the final nitrogen filling. And that is supposed to
translate to less warranty claims at Costco? Less blowouts? Less carnage
on the roads? Give me a break.

+25

I rarely find anything in CR that I think very useful, but here's a case
where they actually seem to have done something of value.

And they illustrate the trouble with "statistics" produced by
proponents--or at least one needs be aware of how can be twisted along
the way.

That 1.3 psi average differential in pressure drop sounds like a lot
when expressed as a percentage of the air-filled --

(2.2/3.5 - 1)*100% = -37%

That seems sizable but if recast as the loss relative to the air the
increase in rate is

(3.5/2.2 - 1)*100% = +59%!!!

It's the latter number the proponents are fond of bandy'ing about to
make one think it's a really, really, big deal.

But, as you point out on the realistic scale of what does it mean to
actual tire pressure, it's only 1.3 psi out of 30 psi or

(3.5-2.2)/30*100% = 4.3%

And, on a more timely basis, that translates to only something barely
over a tenth of a pound difference per month.

It all just "shows to go ya'" one has to be aware of what the divisor is
in such comparisons--decreasing it grossly inflates the percentages as
1/x--inf as x--0 very rapidly as x gets smaller.

So in the larger scheme of things that is what really matters; namely
the actual tire pressure, it just isn't that big of a difference to be a
significant factor in whether a tire is/isn't under-inflated. It's
still going to be the maintenance the owner/operator supplies that's the
controlling factor by far.

The one question I've not taken time to actually calculate is what would
be the water vapor contribution of, say, 50% RH at 70F cold inflation
pressure to see what drop there is owing to the freezing of the water to
essentially remove that contribution. Of course, for highway driving
it's unlikely except in the truly most extreme cold that air temperature
wouldn't rise to above freezing, anyway, restoring a significant
fraction of that loss...

--

On Mon, 10 Nov 2014 00:53:54 -0800, SMS
wrote:

On 11/9/2014 6:15 PM, Vic Smith wrote:

What if the tires are 40 bucks cheaper at the store?

You're making up ridiculous stories, but yes, that would make a
difference. I have compared tire costs many times and Costco is always
much cheaper out the door. Usually at least $100. And that includes
nitrogen inflation.

You can make up "what ifs" until you're blue in the face but that does
not change the facts.

It's not a "what if" for anybody who gets a discount price on tires.

On 11/10/2014 2:53 AM, SMS wrote:
....

... I have compared tire costs many times and Costco is always
much cheaper out the door. Usually at least $100. And that includes
nitrogen inflation.

....

Never seen a Costco service truck show up in the field to handle the
combine traction tire during harvest (at about 10 PM last time, too, not
anything unusual, "just business"). I'll stay with the real dealership
on whom I can count when I need 'em, thankyewverymuch.

A few bucks differential on an inexpensive light vehicle tire is just
noise...

--

"dpb" wrote in message ...
On 11/08/2014 8:58 PM, Jeff Strickland wrote:
...

The set the bead without the core inside of the stem. The air comes out
in a few seconds, they install the core then fill with nitro. I don't
see how this is difficult.

That's still atmospheric pressure of this nasty, wet air everybody's so
concerned about...



But the ratio is so low that it's kinda like the heat in your freezer when
you put a candle inside. I'm all but certain the candle makes heat, but the
ice cubes are not going to melt, so the freezer is still a freezer.

On 11/10/2014 9:36 AM, Jeff Strickland wrote:

"dpb" wrote in message ...
On 11/08/2014 8:58 PM, Jeff Strickland wrote:
...

The set the bead without the core inside of the stem. The air comes out
in a few seconds, they install the core then fill with nitro. I don't
see how this is difficult.

That's still atmospheric pressure of this nasty, wet air everybody's
so concerned about...



But the ratio is so low that it's kinda like the heat in your freezer
when you put a candle inside. I'm all but certain the candle makes heat,
but the ice cubes are not going to melt, so the freezer is still a freezer.

Are you certain...have you calculated the actual fill percentage and
compared that to the 95% claimed needed to be effective? I've not taken
(nor am I going to) the time but it's the underlying question.

I've seen reference to purge cycles; the question is is that a routine
needed when using N to make it effective to the extent it is, anyways,
(which really isn't much as shown in another subthread). Interestingly
enough, our Costco tout hasn't answered/responded to any of the more
factual aspects of the topic.

--

On Mon, 10 Nov 2014 07:50:59 -0600, dpb wrote:

On 11/9/2014 6:00 PM, dpb wrote:
On 11/09/2014 5:34 PM, SMS wrote:
...

...

Certainly if the price structure is not reflective of the cost of
producing the product or service they won't last long...

But they do last. The only reason the big 3 were producing small cars
was because of government requirements that their fleet MPG be at a
certain level. They would much rather have produced only high margin,
high profit, low MPG models. They set their small car prices at market
prices, and lost money on them in order to increase the fleet mpg.

One last comment on your pricing naivete then I'll mark 'Ignore Thread'
before letting this inanity continue further...

Even if they did purposely price a portion of the fleet below cost, (and
I'm certainly not at this point willing to concede that was really so)
it's still the overall cost/revenue for the entire company that's the
significant number. You can think of the loss-leader car as the N throw
away at Costco--it's in their overall cost structure just as the two
bookshelves were in the revised expense account the colleague
resubmitted--it was covered up by using per diem rates instead of
actuals to the point of making up the difference and such. Again, it's
the overall that matters, not each individual piece necessarily.
But anyone who has spent any time immersed in the automotive business
KNOWS certain vehicles are always sold at a loss - certain very
popular models have never earned the company a cent, and others lost
money for several years before becoming "mainstream" and making money.

For years, Toyota lost money on every Hilux sold in North America, but
they sold them for what they could get for them to allow them to
import more Celicas, Coronas, and Corollas - models they could sell
all they could get and more.

The same has happened with virtually every other manufacturer/dealer
at one point or another.

On 11/10/2014 12:25 AM, rbowman wrote:
nestork wrote:

Here in Manitoba we have a publically owned auto insurance company
called "Autopac". I pay about $800 per year for insurance on my 1998
Chevy Cavalier, and I'm told that's pretty good compared to for-profit
insurance companies operating in other provinces.

Even factoring in the exchange rate, that's pretty steep.


If that is liability insurance, it sounds about right. Depends on where
you live, policy limits, etc. I'm paying about $1000 for full coverage
on a two year old car.

On 11/10/2014 10:03 AM, dpb wrote:
On 11/10/2014 9:36 AM, Jeff Strickland wrote:
"dpb" wrote in message ...
....

That's still atmospheric pressure of this nasty, wet air everybody's
so concerned about...
....
But the ratio is so low that it's kinda like the heat in your freezer
when you put a candle inside. I'm all but certain the candle makes heat,
but the ice cubes are not going to melt, so the freezer is still a
freezer.

Are you certain...have you calculated the actual fill percentage and
compared that to the 95% claimed needed to be effective? I've not taken
(nor am I going to) the time but it's the underlying question.
....

Actually, it's not that tough to get pretty good estimate...

14.7/(14.7+30) = 0.33 -- 33% air by fraction of total pressures. So
w/o purge you're only going to be 2/3rds or so N...

--

Ed Pawlowski wrote:
On 11/10/2014 12:25 AM, rbowman wrote:
nestork wrote:

Here in Manitoba we have a publically owned auto
insurance company
called "Autopac". I pay about $800 per year for
insurance on my
1998 Chevy Cavalier, and I'm told that's pretty good
compared to
for-profit insurance companies operating in other
provinces.

Even factoring in the exchange rate, that's pretty steep.


If that is liability insurance, it sounds about right.
Depends on
where you live, policy limits, etc. I'm paying about
$1000 for full
coverage on a two year old car.

I'm paying 950 for 2 vehicles with full coverage. Ones about
10yrs old the other about 8, I guess I've got a good deal
then

On 11/10/2014 1:02 PM, ChairMan wrote:
Ed wrote:
On 11/10/2014 12:25 AM, rbowman wrote:
nestork wrote:

Here in Manitoba we have a publically owned auto
insurance company
called "Autopac". I pay about $800 per year for
insurance on my
1998 Chevy Cavalier, and I'm told that's pretty good
compared to
for-profit insurance companies operating in other
provinces.

Even factoring in the exchange rate, that's pretty steep.


If that is liability insurance, it sounds about right.
Depends on
where you live, policy limits, etc. I'm paying about
$1000 for full
coverage on a two year old car.

I'm paying 950 for 2 vehicles with full coverage. Ones about
10yrs old the other about 8, I guess I've got a good deal
then

Can't compare just rates; need to know about limits of liability,
deductibles, all that other stuff that changes the rates drastically for
differing levels of the same basic coverage items.

And, liability in particular is _very_ jurisdiction dependent. In VA it
was roughly 3X the KS rate for the same vehicle/coverage and that was 40
yr ago. I'd expect it to be an even wider disparity now.

--

On Mon, 10 Nov 2014 12:53:38 -0600, dpb wrote:

On 11/10/2014 10:03 AM, dpb wrote:
On 11/10/2014 9:36 AM, Jeff Strickland wrote:
"dpb" wrote in message ...
...

That's still atmospheric pressure of this nasty, wet air everybody's
so concerned about...
...
But the ratio is so low that it's kinda like the heat in your freezer
when you put a candle inside. I'm all but certain the candle makes heat,
but the ice cubes are not going to melt, so the freezer is still a
freezer.

Are you certain...have you calculated the actual fill percentage and
compared that to the 95% claimed needed to be effective? I've not taken
(nor am I going to) the time but it's the underlying question.
...

Actually, it's not that tough to get pretty good estimate...

14.7/(14.7+30) = 0.33 -- 33% air by fraction of total pressures. So
w/o purge you're only going to be 2/3rds or so N...
Actually, a whiole lot more than that. Aprox 1/3 will be 80%
nitrogen, and 2/3 will be 98% =/- Notrogen - so closer to 96%
nitrogen.

On Mon, 10 Nov 2014 13:11:35 -0600, dpb wrote:

On 11/10/2014 1:02 PM, ChairMan wrote:
Ed wrote:
On 11/10/2014 12:25 AM, rbowman wrote:
nestork wrote:

Here in Manitoba we have a publically owned auto
insurance company
called "Autopac". I pay about $800 per year for
insurance on my
1998 Chevy Cavalier, and I'm told that's pretty good
compared to
for-profit insurance companies operating in other
provinces.

Even factoring in the exchange rate, that's pretty steep.


If that is liability insurance, it sounds about right.
Depends on
where you live, policy limits, etc. I'm paying about
$1000 for full
coverage on a two year old car.

I'm paying 950 for 2 vehicles with full coverage. Ones about
10yrs old the other about 8, I guess I've got a good deal
then

Can't compare just rates; need to know about limits of liability,
deductibles, all that other stuff that changes the rates drastically for
differing levels of the same basic coverage items.

And, liability in particular is _very_ jurisdiction dependent. In VA it
was roughly 3X the KS rate for the same vehicle/coverage and that was 40
yr ago. I'd expect it to be an even wider disparity now.
Here in Ontario, insuring with the same company, you can pay twice as
much if you drive in Toronto vs, say, Wiarton.

On Mon, 10 Nov 2014 12:53:38 -0600, dpb wrote:
On 11/10/2014 10:03 AM, dpb wrote:
....

Actually, it's not that tough to get pretty good estimate...

14.7/(14.7+30) = 0.33 -- 33% air by fraction of total pressures. So
w/o purge you're only going to be 2/3rds or so N...
Actually, a whiole lot more than that. Aprox 1/3 will be 80%
nitrogen, and 2/3 will be 98% =/- Notrogen - so closer to 96%
nitrogen.


That's so, yes...the 1/3rd is air:N, my bad.

OK, guess that may be "close enough" to make some difference. Wonder
what the Consumer Reports test data would've been if they'd just done N
fill instead of purge.

--

wrote:

Here in Ontario, insuring with the same company, you can pay twice as
much if you drive in Toronto vs, say, Wiarton.

That's understandable, particularly if you spend much time on the Mac and
Jack Speedway.

On Mon, 10 Nov 2014 18:51:33 -0700, rbowman
wrote:

wrote:

Here in Ontario, insuring with the same company, you can pay twice as
much if you drive in Toronto vs, say, Wiarton.

That's understandable, particularly if you spend much time on the Mac and
Jack Speedway.
Worse yet, the Don Valley Parking lot or downtown

"dpb" wrote in message ...
On 11/10/2014 10:03 AM, dpb wrote:
On 11/10/2014 9:36 AM, Jeff Strickland wrote:
"dpb" wrote in message ...
...

That's still atmospheric pressure of this nasty, wet air everybody's
so concerned about...
...
But the ratio is so low that it's kinda like the heat in your freezer
when you put a candle inside. I'm all but certain the candle makes heat,
but the ice cubes are not going to melt, so the freezer is still a
freezer.

Are you certain...have you calculated the actual fill percentage and
compared that to the 95% claimed needed to be effective? I've not taken
(nor am I going to) the time but it's the underlying question.
...

Actually, it's not that tough to get pretty good estimate...

14.7/(14.7+30) = 0.33 -- 33% air by fraction of total pressures. So w/o
purge you're only going to be 2/3rds or so N...

--

That cannot be right, but I have no idea the formula that is needed.

An "empty tire", one with 1 atmosphere of air inside will not pollute with
any significance the contents it takes to bring that tire to 30+ psi. The
empty tire will contain air, no doubt. But filling the tire to 30 psi will
most certainly result in a dillution of the "empty" contents to far less
than 1/3. Surely the anology of a candle in the freezer has to be pretty
accurate, even if not the same type of thing.

An "empty," balloon has air inside, and filling it with helium still results
in a balloon that floats.

On 11/11/2014 9:30 AM, Jeff Strickland wrote:
"dpb" wrote in message ...
....

Actually, it's not that tough to get pretty good estimate...

14.7/(14.7+30) = 0.33 -- 33% air by fraction of total pressures. So
w/o purge you're only going to be 2/3rds or so N...

--

That cannot be right, but I have no idea the formula that is needed.
....

It _IS_ right for what it is... _Air_:N ratio. I just didn't go ahead
to then account for the 80% N content in the entrained air (as clare
pointed out the oversight). See the followup there.

All it takes for the He balloon to float is that the density be less
than that of air--nothing even close to the 95% fraction would be
required so it's not a useful comparison.

I was thinking the ratio wouldn't be quite so high altho the 80% N in
air is the saving grace; just hadn't computed the actual fraction
previously.

It would be interesting to see the CR data/experiment w/ a control
population that were just backfilled w/ N alongside the purged set they
did just to see if it showed up.

After the above computation I'll concede it is sufficient to likely be
able to produce the net savings of roughly 1.3 lb less diffusion
pressure drop over a year than air; I'll still contend that isn't
sufficient difference to be of any real value to the end user.

In large part that that's so can be shown because the temperature swing
from yesterday afternoon's high of 80 F to this morning's low of 19F
(it's all the way up to 22 F now at 10 AM) results in a pressure swing
of (20+460)/(80+460)*30 psi = -3.3 psi or 2.5X that annual loss
differential. It's just not significant difference in what happens w/ N
in lieu of air for passenger car applications.

So the car this morning is underinflated but by this time two weeks from
now if were to correct for it it'll be back to seasonal normals and
they'd be over-pressured by about that much.

--

On 11/11/2014 9:50 AM, dpb wrote:
On 11/11/2014 9:30 AM, Jeff Strickland wrote:
"dpb" wrote in message ...
...

Actually, it's not that tough to get pretty good estimate...

14.7/(14.7+30) = 0.33 -- 33% air by fraction of total pressures. So
w/o purge you're only going to be 2/3rds or so N...

--

That cannot be right, but I have no idea the formula that is needed.
...

It _IS_ right for what it is... _Air_:N ratio. I just didn't go ahead to
then account for the 80% N content in the entrained air (as clare
pointed out the oversight). See the followup there.

*ADDENDUM*

...It _IS_ right for what it is... _Air_:N ratio....

More precisely, it's Air:Total ratio.

And, to explain if don't see it, it's simply the absolute pressure ratio
instead of gauge pressures. 14.7 is normal atmospheric pressure; hence
when the tire gauge reads '0' that's what's there. The total pressure
when the gauge reads 30 psi is then roughly 45 psia (or 30 psig).

Dalton's Law says partial pressures are additive.

--

On 11/11/2014 10:30 AM, Jeff Strickland wrote:


An "empty," balloon has air inside, and filling it with helium still
results in a balloon that floats.



Most empty balloons I've seen were collapsed
flat before filling.


-
..
Christopher A. Young
Learn about Jesus
www.lds.org
..

On 11/10/2014 9:14 AM, wrote:

For years, Toyota lost money on every Hilux sold in North America, but
they sold them for what they could get for them to allow them to
import more Celicas, Coronas, and Corollas - models they could sell
all they could get and more.

The same has happened with virtually every other manufacturer/dealer
at one point or another.

Yep. Prices are usually set at "what you can get" not your cost plus
some fixed mark-up. There are some exceptions, but not many. A _LOT_ of
people don't understand this, not just djb. Now it is true that some
companies drop products if they are losing money on them and there is no
other reason to keep the product line (but often there are reasons that
make sense).

Costco prices would be no lower if they did not provide nitrogen. It's
just not they way retail works.

On Tuesday, November 11, 2014 2:15:31 PM UTC-5, SMS wrote:
On 11/10/2014 9:14 AM, wrote:

For years, Toyota lost money on every Hilux sold in North America, but
they sold them for what they could get for them to allow them to
import more Celicas, Coronas, and Corollas - models they could sell
all they could get and more.

The same has happened with virtually every other manufacturer/dealer
at one point or another.

Yep. Prices are usually set at "what you can get" not your cost plus
some fixed mark-up. There are some exceptions, but not many. A _LOT_ of
people don't understand this, not just djb. Now it is true that some
companies drop products if they are losing money on them and there is no
other reason to keep the product line (but often there are reasons that
make sense).

Costco prices would be no lower if they did not provide nitrogen. It's
just not they way retail works.

Economics 101 says you're wrong.

On Tue, 11 Nov 2014 07:30:07 -0800, "Jeff Strickland"
wrote:


"dpb" wrote in message ...
On 11/10/2014 10:03 AM, dpb wrote:
On 11/10/2014 9:36 AM, Jeff Strickland wrote:
"dpb" wrote in message ...
...

That's still atmospheric pressure of this nasty, wet air everybody's
so concerned about...
...
But the ratio is so low that it's kinda like the heat in your freezer
when you put a candle inside. I'm all but certain the candle makes heat,
but the ice cubes are not going to melt, so the freezer is still a
freezer.

Are you certain...have you calculated the actual fill percentage and
compared that to the 95% claimed needed to be effective? I've not taken
(nor am I going to) the time but it's the underlying question.
...

Actually, it's not that tough to get pretty good estimate...

14.7/(14.7+30) = 0.33 -- 33% air by fraction of total pressures. So w/o
purge you're only going to be 2/3rds or so N...

--

That cannot be right, but I have no idea the formula that is needed.

An "empty tire", one with 1 atmosphere of air inside will not pollute with
any significance the contents it takes to bring that tire to 30+ psi. The
empty tire will contain air, no doubt. But filling the tire to 30 psi will
most certainly result in a dillution of the "empty" contents to far less
than 1/3. Surely the anology of a candle in the freezer has to be pretty
accurate, even if not the same type of thing.

An "empty," balloon has air inside, and filling it with helium still results
in a balloon that floats.

An "empty" balloon has virtually no air because it is "flat" The same
can be said for a tube, but not a tire. A tire has it's full volume of
air at 1 atmosphere. That 1 apmosphere is roughly 80% nitrogen.
Inflate to 3 atmospheres is 3 times the mass - correct? So 2 thirds of
the volume is 96-98% nitrogen and 1 third is 80% nitrogen. Lets say
the nitrogen fill is 98%., so 98+98+80/3=92%.

Close enough anyway, unless it takes the addition of more than twice
the volume of the tire to raise the pressure to 3 atmospheres from 1.

On Tue, 11 Nov 2014 11:15:27 -0800, SMS
wrote:

On 11/10/2014 9:14 AM, wrote:

For years, Toyota lost money on every Hilux sold in North America, but
they sold them for what they could get for them to allow them to
import more Celicas, Coronas, and Corollas - models they could sell
all they could get and more.

The same has happened with virtually every other manufacturer/dealer
at one point or another.

Yep. Prices are usually set at "what you can get" not your cost plus
some fixed mark-up. There are some exceptions, but not many. A _LOT_ of
people don't understand this, not just djb. Now it is true that some
companies drop products if they are losing money on them and there is no
other reason to keep the product line (but often there are reasons that
make sense).

Costco prices would be no lower if they did not provide nitrogen. It's
just not they way retail works.
The only way Costco's regular prices would be lower is if someone
else was selling the same tire for less and they didn't want to loose
market share. If they can sell 100 at a dollar profit they make more
than selling 48 at 2 dollars profit

On Tuesday, November 11, 2014 5:41:26 PM UTC-5, wrote:
On Tue, 11 Nov 2014 11:15:27 -0800, SMS
wrote:

On 11/10/2014 9:14 AM, wrote:

For years, Toyota lost money on every Hilux sold in North America, but
they sold them for what they could get for them to allow them to
import more Celicas, Coronas, and Corollas - models they could sell
all they could get and more.

The same has happened with virtually every other manufacturer/dealer
at one point or another.

Yep. Prices are usually set at "what you can get" not your cost plus
some fixed mark-up. There are some exceptions, but not many. A _LOT_ of
people don't understand this, not just djb. Now it is true that some
companies drop products if they are losing money on them and there is no
other reason to keep the product line (but often there are reasons that
make sense).

Costco prices would be no lower if they did not provide nitrogen. It's
just not they way retail works.
The only way Costco's regular prices would be lower is if someone
else was selling the same tire for less and they didn't want to loose
market share. If they can sell 100 at a dollar profit they make more
than selling 48 at 2 dollars profit

That's part of it. The other part is that an important part of where
supply and demand curves meet for a product are the total cost of
production. Nitrogen costs money. Unless you believe that it actually
saves the tire company money, by less warranty claims, less customers
coming back, etc, which I don't. If you add cost to a product, then
economics 101 says that the result is a higher market equilibrium price.

That's the economics behind it. What Costco actually does, none of us
know. They management could set the price based on astrology. But SMS
keeps insisting that costs have nothing do to with it. That's just not
true. Costs directly affect prices. It doesn't have to be that Costco
figues their cost and adds X%. Per the above, market forces determine the
price, but costs are directly involved in what the price is. Also, IDK
about Costco, but typically businesses know their costs, keep and eye
on their margins, etc. I would be surprised if Costco didn't know to
the penny how much their cost is to install a tire, including the nitrogen
and they keep that in mind when setting the price.

trader_4 wrote:

I would be surprised if Costco didn't know to
the penny how much their cost is to install a tire, including the nitrogen
and they keep that in mind when setting the price.

I'm late to the party so maybe someone's also mentioned this, but
perhaps Costco figures if someone is dumb enough think they have to
drive miles to top up their tires instead of doing it in the comfort
of their own garage they might also, while there, go in and buy an
impulse flatscreen.

On 11/11/2014 1:17 PM, trader_4 wrote:
On Tuesday, November 11, 2014 2:15:31 PM UTC-5, SMS wrote:
On 11/10/2014 9:14 AM, wrote:

For years, Toyota lost money on every Hilux sold in North America, but
they sold them for what they could get for them to allow them to
import more Celicas, Coronas, and Corollas - models they could sell
all they could get and more.

The same has happened with virtually every other manufacturer/dealer
at one point or another.

Yep. Prices are usually set at "what you can get" not your cost plus
some fixed mark-up. There are some exceptions, but not many. A _LOT_ of
people don't understand this, not just djb. Now it is true that some
companies drop products if they are losing money on them and there is no
other reason to keep the product line (but often there are reasons that
make sense).

Costco prices would be no lower if they did not provide nitrogen. It's
just not they way retail works.

Economics 101 says you're wrong.

But Marketing 432 says that I'm right.

Read this book: http://www.amazon.com/dp/0387769994 and you will gain
an understanding of how prices are set.

On 11/11/2014 2:41 PM, wrote:
On Tue, 11 Nov 2014 11:15:27 -0800, SMS
wrote:

On 11/10/2014 9:14 AM, wrote:

For years, Toyota lost money on every Hilux sold in North America, but
they sold them for what they could get for them to allow them to
import more Celicas, Coronas, and Corollas - models they could sell
all they could get and more.

The same has happened with virtually every other manufacturer/dealer
at one point or another.

Yep. Prices are usually set at "what you can get" not your cost plus
some fixed mark-up. There are some exceptions, but not many. A _LOT_ of
people don't understand this, not just djb. Now it is true that some
companies drop products if they are losing money on them and there is no
other reason to keep the product line (but often there are reasons that
make sense).

Costco prices would be no lower if they did not provide nitrogen. It's
just not they way retail works.
The only way Costco's regular prices would be lower is if someone
else was selling the same tire for less and they didn't want to loose
market share. If they can sell 100 at a dollar profit they make more
than selling 48 at 2 dollars profit

Remember, including nitrogen probably makes Costco far more money than
not including it, despite the small extra cost they incur for the
nitrogen generators.

The key is to adopt a strategy that increases volume. Including nitrogen
enables them to attract more customers and the extra profit from selling
more tires more than offsets the cost of nitrogen, especially because
the cost of the nitrogen generators is now amortized over more units.
There are side benefits of the nitrogen as well in terms of lower
warranty costs and lower labor costs.

There is a general ignorance, among those that have never taken any
marketing coursework, about pricing strategy.

On 11/12/2014 4:22 AM, trader_4 wrote:

I would be surprised if Costco didn't know to
the penny how much their cost is to install a tire, including the nitrogen
and they keep that in mind when setting the price.

You keep making the error of believing that price are set based solely
on the retailers costs, when so much more goes into pricing strategy.

Look at gas stations. Right now you can buy a gallon of top tier
gasoline in my area for $2.80 or $3.60. There is essentially no
difference in the quality of the gasoline. The retailers are buying fuel
from the same refinery and the wholesale cost is almost the same.

Why does a station charge 80¢ per gallon more, knowing that they will
sell far less volume? There are valid reasons for this that have nothing
to do with their costs.

On 11/12/2014 9:03 AM, scarecrow wrote:
trader_4 wrote:

I would be surprised if Costco didn't know to
the penny how much their cost is to install a tire, including the nitrogen
and they keep that in mind when setting the price.

I'm late to the party so maybe someone's also mentioned this, but
perhaps Costco figures if someone is dumb enough think they have to
drive miles to top up their tires instead of doing it in the comfort
of their own garage they might also, while there, go in and buy an
impulse flatscreen.

Tires are very high margin items, like mattresses. You want to maximize
your sales volume. Prices are set to maximize profit, they are not set
by calculating expenses and then adding some percentage to that.
Costco's strategy is to maximize profit by increasing their market share
by pricing things competitively.

Costco also seems to have a corporate philosophy of not being sleazy.
They never charged separately for valves or road hazard and they never
set tire prices artificially low and then tried to make it up with high
mounting and balancing prices. Even now you see tire stores advertise
that they'll meet Costco's tire prices but when you see the total price
it's much higher even though they meet the basic price per tire.

"SMS" wrote in message
...
Costco also seems to have a corporate philosophy of not being sleazy. They
never charged separately for valves or road hazard and they never set tire
prices artificially low and then tried to make it up with high mounting
and balancing prices. Even now you see tire stores advertise that they'll
meet Costco's tire prices but when you see the total price it's much
higher even though they meet the basic price per tire.


The way I price tires is to ask for the total out the door price including
tax and anything else.

As you say , some places dollar you to death adding things on like mounting
and valve stems. The way I look at it is I am not buying a tire to take
home, I want it on the car and ready to drive off. I doubt very many
people go to a store and buy tires and take them home. Maybe a few to make
planters out of, but usually those are old tires.




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SMS wrote:

On 11/12/2014 9:03 AM, scarecrow wrote:

I'm late to the party so maybe someone's also mentioned this, but
perhaps Costco figures if someone is dumb enough think they have to
drive miles to top up their tires instead of doing it in the comfort
of their own garage they might also, while there, go in and buy an
impulse flatscreen.

Tires are very high margin items, like mattresses.

If your argument is correct and tires really do last longer with
nitrogen then it appears that Costco is shooting themselves in the
foot since they would have less repeat sales over time, not more.

You want to maximize
your sales volume. Prices are set to maximize profit, they are not set
by calculating expenses and then adding some percentage to that.
Costco's strategy is to maximize profit by increasing their market share
by pricing things competitively.

From what I've read so far you have no clue why Costco does what it
does. It's pure guesswork on your part.

Costco also seems to have a corporate philosophy of not being sleazy.
They never charged separately for valves or road hazard and they never
set tire prices artificially low and then tried to make it up with high
mounting and balancing prices.

When I was a Costco member I could almost always find the same or
better deal on a high dollar item elsewhere. But the two stores near
me are always packed so what do I know. Or maybe it should be there's
one born every second?

On Thu, 13 Nov 2014 14:50:44 -0500, "Ralph Mowery"
wrote:


"SMS" wrote in message
.. .
Costco also seems to have a corporate philosophy of not being sleazy. They
never charged separately for valves or road hazard and they never set tire
prices artificially low and then tried to make it up with high mounting
and balancing prices. Even now you see tire stores advertise that they'll
meet Costco's tire prices but when you see the total price it's much
higher even though they meet the basic price per tire.


The way I price tires is to ask for the total out the door price including
tax and anything else.

As you say , some places dollar you to death adding things on like mounting
and valve stems. The way I look at it is I am not buying a tire to take
home, I want it on the car and ready to drive off. I doubt very many
people go to a store and buy tires and take them home. Maybe a few to make
planters out of, but usually those are old tires.




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http://www.avast.com
I used to buy ALL of my tires "cash and carry" - and take them home
and install and balance them. That was when I had easy access to the
equipment. Now that I don't have easy free access to the equipment, I
buy them installed on the rim and balanced. All told, I bought a lot
more bare, uninstalled tires than I have installed.
But I am, admittedly, not your average customer.

On Thu, 13 Nov 2014 13:32:05 -0700, scarecrow
wrote:

SMS wrote:

On 11/12/2014 9:03 AM, scarecrow wrote:

I'm late to the party so maybe someone's also mentioned this, but
perhaps Costco figures if someone is dumb enough think they have to
drive miles to top up their tires instead of doing it in the comfort
of their own garage they might also, while there, go in and buy an
impulse flatscreen.

Tires are very high margin items, like mattresses.
Actually, the margin on tires is QUITE slim. If you are going to get
rich selling tires, you will have to sell a lot of them. One place
where I worked we sold over 1000 sets of snow tires each winter out of
a 3 bay service station. I'm sure we made more on the installation
than on the tires back in 1969-71. The wholesaler might make a better
margin than the retailer - and Costco is, in effect, both so they can
afford to sell them for less than the average independent shop - for
sure.

If your argument is correct and tires really do last longer with
nitrogen then it appears that Costco is shooting themselves in the
foot since they would have less repeat sales over time, not more.

No, because people will buy tires from places that sell tires that
last - so the customer comes back to buy more tires if the tires stand
up well - they buy tires elsewhere if they do not - -with price being
a secondary consideration in many cases.
And the average car owner owns a car long enough to wear out about 1
1/2 sets of good tires.- so they will be in to buy the next set of
tires for their next car more likely than for this one.

You want to maximize
your sales volume. Prices are set to maximize profit, they are not set
by calculating expenses and then adding some percentage to that.
Costco's strategy is to maximize profit by increasing their market share
by pricing things competitively.

From what I've read so far you have no clue why Costco does what it
does. It's pure guesswork on your part.

Costco also seems to have a corporate philosophy of not being sleazy.
They never charged separately for valves or road hazard and they never
set tire prices artificially low and then tried to make it up with high
mounting and balancing prices.

When I was a Costco member I could almost always find the same or
better deal on a high dollar item elsewhere. But the two stores near
me are always packed so what do I know. Or maybe it should be there's
one born every second?
Used to be there were great deals at costco in Canada - now I can
usually buy just about anything for less elsewhere if I look hard
enough. The advantage of Costco is they have EVERYTHING under one
roof.

I'm not a member any more - found it wasn't worth it for me.

On Thu, 13 Nov 2014 17:35:36 -0500, wrote:

The advantage of Costco is they have EVERYTHING under one
roof.

So does my Walmart. And you don't have to pay to get in...

On Thursday, November 13, 2014 2:01:06 PM UTC-5, SMS wrote:
On 11/11/2014 1:17 PM, trader_4 wrote:
On Tuesday, November 11, 2014 2:15:31 PM UTC-5, SMS wrote:
On 11/10/2014 9:14 AM, wrote:

For years, Toyota lost money on every Hilux sold in North America, but
they sold them for what they could get for them to allow them to
import more Celicas, Coronas, and Corollas - models they could sell
all they could get and more.

The same has happened with virtually every other manufacturer/dealer
at one point or another.

Yep. Prices are usually set at "what you can get" not your cost plus
some fixed mark-up. There are some exceptions, but not many. A _LOT_ of
people don't understand this, not just djb. Now it is true that some
companies drop products if they are losing money on them and there is no
other reason to keep the product line (but often there are reasons that
make sense).

Costco prices would be no lower if they did not provide nitrogen. It's
just not they way retail works.

Economics 101 says you're wrong.

But Marketing 432 says that I'm right.

Read this book: http://www.amazon.com/dp/0387769994 and you will gain
an understanding of how prices are set.

Look, you've made all kinds of extraordinary claims here, without a shred
of proof. You've claimed that all tire manufacturers recommend nitrogen.
I quickly provided you with a link and reference to what Michelin says
about nitrogen. And they clearly aren't endorsing it. Their position is
closer to "use it if you want". You claimed nitrogen leads to less warranty
claims, less customer returns, again with no proof at all. In reality, the
only test data I've seen was at Consumer Reports, where they purged tires,
left them filled with N for a year and wound up with about 1 PSI difference.
How that translates to any of the wild claims, IDK.

As to how pricing is set in free markets, you don't know what you're talking
about. I know perfectly well how businesses set prices. They set them
based on maximizing profits and no book is going to change that. From the
fact that they don't directly set the selling price just based on their
costs, you incorrectly conclude that the cost has no effect. It does. It
affects the demand curve for the product. Apparently there are people like
you who believe nitrogen is a very important item. Therefore, economics 101
tells us that those people are willing to pay more for tires that are mounted
with them. That creates a different demand curve for tires with nitrogen as
opposed to tires without. Many people who pay X for a tire with regular air
will pay X+ for a tire with nitrogen. That leads to higher prices.

Now, as I've said before, neither you nor I know for sure how Costco sets it's
tire prices. It could be that they throw a dart at a board. It could be that
they lose money on every tire sold and don't give a damn. But economics
is a science and the expected result in a free market when you increase the
cost of production is higher prices. Prices go up to maintain the same margins.