Nitrogen in Car tyres

[Camdor]

Does this actually work? Noticed Kwik Fit are saying nitrogen extends
tyre life by 25% and fuel economy by 10%. They are chargin £1.50 per
tyre to inflate it with nitrogen.

I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

[Clive George]

Post by Camdor
Does this actually work? Noticed Kwik Fit are saying nitrogen extends
tyre life by 25% and fuel economy by 10%.

They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

[Andy Cap]

Post by Clive George
They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

FROM THE KWIK FIT SITE :-

" Nitrogen

Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.

Having a tyre that does not deflate means you will improve fuel consumption and
will probably improve safety standards too. It’s not yet standard practice but
Nitrogen could well be here to stay as a result. "

Andy C

[Clive George]

Post by Andy Cap

Post by Clive George
They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.
Having a tyre that does not deflate means you will improve fuel consumption and
will probably improve safety standards too. It’s not yet standard practice but
Nitrogen could well be here to stay as a result. "

Yes, and do you believe everything you read on the kwik fit site? :-)

The second half of the first paragraph is written by somebody who really
doesn't have a clue about what they're talking about. They could at
least have had somebody proof read it so it actually says what they want
it to.

[Andy Cap]

Post by Clive George

Post by Andy Cap
FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.
Having a tyre that does not deflate means you will improve fuel consumption and
will probably improve safety standards too. It’s not yet standard practice but
Nitrogen could well be here to stay as a result. "

Yes, and do you believe everything you read on the kwik fit site? :-)
The second half of the first paragraph is written by somebody who really
doesn't have a clue about what they're talking about. They could at
least have had somebody proof read it so it actually says what they want
it to.

I never said I believed it ! ;-)

I was quite happy with your explanation. I simply pasted it for reference.

Andy C

[misterroy]

Post by Clive George

Post by Andy Cap

Post by Clive George
They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.
Having a tyre that does not deflate means you will improve fuel consumption and
will probably improve safety standards too. It’s not yet standard practice but
Nitrogen could well be here to stay as a result. "

Yes, and do you believe everything you read on the kwik fit site? :-)
The second half of the first paragraph is written by somebody who really
doesn't have a clue about what they're talking about. They could at
least have had somebody proof read it so it actually says what they want
it to.

http://wiki.answers.com/Q/How_does_the_size_of_a_nitrogen_molecule_compare_to_that_of_oxygen

[harry]

Post by Clive George

Post by Andy Cap

Post by Clive George
They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.
Having a tyre that does not deflate means you will improve fuel consumption and
will probably improve safety standards too. It’s not yet standard practice but
Nitrogen could well be here to stay as a result. "

Yes, and do you believe everything you read on the kwik fit site? :-)
The second half of the first paragraph is written by somebody who really
doesn't have a clue about what they're talking about. They could at
least have had somebody proof read it so it actually says what they want
it to.

http://wiki.answers.com/Q/How_does_the_size_of_a_nitrogen_molecule_co...- Hide quoted text -
- Show quoted text -

Years ago there was a system for getting oxygen out of air by a
membrane "filter" and very high pressure. It never caught on.
This might be it.
http://www.freepatentsonline.com/5296110.html

[Gordon Henderson]

Post by harry
Years ago there was a system for getting oxygen out of air by a
membrane "filter" and very high pressure. It never caught on.
This might be it.
http://www.freepatentsonline.com/5296110.html

Actually it sort of has caught on - in certian fields, and it's used
to produce oxygen rich gas rather than Nitrogen rich - up to 40-50%
O2 depending on the equipment... And who mght use it - Scuba divers who
want Nitrox...

Gordon

[dennis@home]

In article

Post by harry
Years ago there was a system for getting oxygen out of air by a
membrane "filter" and very high pressure. It never caught on.
This might be it.
http://www.freepatentsonline.com/5296110.html

Actually it sort of has caught on

Probably not.. zeolite absorbs the oxygen at about 1.3 atmospheres and then
releases it when the pressure drops.
So you can concentrate oxygen from air with a simple compressor and a couple
of valves, choosing different valve timing will produce oxygen depleted air
(~nitrogen) to blow up your tyres. I can't imagine them using one that
requires high pressures when they can do it with low pressures.

- in certian fields, and it's used
to produce oxygen rich gas rather than Nitrogen rich - up to 40-50%
O2 depending on the equipment... And who mght use it - Scuba divers who
want Nitrox...
Gordon

[dennis@home]

Post by harry
Years ago there was a system for getting oxygen out of air by a
membrane "filter" and very high pressure. It never caught on.
This might be it.
http://www.freepatentsonline.com/5296110.html

You can extract the oxygen quite easily using something called zeolite, its
used in oxygen concentrators for medical use.
The remaining air must be mainly nitrogen and is probably OK for inflating
tyres.
I would imagine you can buy machines to do this just for the tyre business.

[d***@yahoo.co.uk]

Post by ***@home

Post by harry
Years ago there was a system for getting oxygen out of air by a
membrane "filter" and very high pressure. It never caught on.
This might be it.
http://www.freepatentsonline.com/5296110.html

You can extract the oxygen quite easily using something called zeolite, its
used in oxygen concentrators for medical use.
The remaining air must be mainly nitrogen and is probably OK for inflating
tyres.
I would imagine you can buy machines to do this just for the tyre business.

Many larger pubs and Clubs have such machines on rental from one of
the big gas names such as B O C or Air liquide .
The nitrogen produced is blended with Co2 to the different ratios
required by the various lagers and keg bitters and keg stouts. It
cuts down on the amount of Co2 that has to be delivered, and the
systems were introduced about 15 years when the marketing men
convinced themselves that the public wanted beer to be served all
"creamy".Previously it was almost only Guinness that needed the
nitrogen mixture.
What is now that branch of air liquide was then Calor and I well
remember a local landlord aghast at being told that Calor gas were
going be fitting such a system in his pub. He had got the wrong end of
the stick somewhat though the beer he sold may well have been improved
if it had tasted of propane.

G.Harman

[John]

Post by Clive George

On Tue, 05 Oct 2010 17:49:23 +0100, Clive

Post by Clive George
They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.
Having a tyre that does not deflate means you will improve fuel consumption and
will probably improve safety standards too. It’s not yet standard practice but
Nitrogen could well be here to stay as a result. "

Yes, and do you believe everything you read on the kwik fit site? :-)
The second half of the first paragraph is written by somebody who really
doesn't have a clue about what they're talking about. They could at least
have had somebody proof read it so it actually says what they want it to.

Probably cheaper to buy Nitrogen than to service and insure a compressor.

[Jerry]

"John" <***@ntlworld.com> wrote in message news:d3Lqo.49367$***@newsfe16.ams2...

<snip>
:
: Probably cheaper to buy Nitrogen than to service and insure a
compressor.
:

Except hat just about every power tool, including the tyre
changing machines, in the workshop need to such a compressed air
supply...

[Lobster]

Post by Andy Cap

Post by Clive George
They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.

Cool. So where am I going to get my hands on this new wonder-mix of
nitrogen and oxygen, then? I'd definitely be prepared to pay a premium
for that, rather than just using poxy air.

David

[The Natural Philosopher]

Post by Lobster

On Tue, 05 Oct 2010 17:49:23 +0100, Clive

Post by Clive George
They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.

Cool. So where am I going to get my hands on this new wonder-mix of
nitrogen and oxygen, then? I'd definitely be prepared to pay a premium
for that, rather than just using poxy air.

well largely air is a mixture of nitrogen, and oxygen. With a few things
like CO2 thrown in as well.

Post by Lobster
David

[Lobster]

Post by The Natural Philosopher

Post by Lobster

On Tue, 05 Oct 2010 17:49:23 +0100, Clive

Post by Clive George
They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.

Cool. So where am I going to get my hands on this new wonder-mix of
nitrogen and oxygen, then? I'd definitely be prepared to pay a premium
for that, rather than just using poxy air.

well largely air is a mixture of nitrogen, and oxygen. With a few things
like CO2 thrown in as well.

No shit, Sherlock...!?

[dennis@home]

Post by The Natural Philosopher
well largely air is a mixture of nitrogen, and oxygen. With a few things
like CO2 thrown in as well.

I think they may already know that. ;-)

[Dave Baker]

Post by The Natural Philosopher

Post by Lobster

Post by Andy Cap
FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that's exactly what
motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it's possible to negate the issue of slow deflation,
which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.

Cool. So where am I going to get my hands on this new wonder-mix of
nitrogen and oxygen, then? I'd definitely be prepared to pay a premium
for that, rather than just using poxy air.

well largely air is a mixture of nitrogen, and oxygen. With a few things
like CO2 thrown in as well.

WHOOOOOOSH.

[Adrian]

Post by Dave Baker

Post by The Natural Philosopher

Post by Lobster
Cool. So where am I going to get my hands on this new wonder-mix of
nitrogen and oxygen, then? I'd definitely be prepared to pay a
premium for that, rather than just using poxy air.

well largely air is a mixture of nitrogen, and oxygen. With a few
things like CO2 thrown in as well.

WHOOOOOOSH.

'ere, Dave. I think you've just picked a nail up in that tyre.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Lobster

Post by Lobster
Cool. So where am I going to get my hands on this new wonder-mix of
nitrogen and oxygen, then? I'd definitely be prepared to pay a premium
for that, rather than just using poxy air.

I've got some I can sell you. I'll send a boxful, ok?

[ARWadsworth]

Post by Grimly Curmudgeon
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Lobster

Post by Lobster
Cool. So where am I going to get my hands on this new wonder-mix of
nitrogen and oxygen, then? I'd definitely be prepared to pay a
premium for that, rather than just using poxy air.

I've got some I can sell you. I'll send a boxful, ok?

The bottled stuff is so much better.

Adam

[george [dicegeorge]]

Post by ARWadsworth

Post by Grimly Curmudgeon
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Lobster

Post by Lobster
Cool. So where am I going to get my hands on this new wonder-mix of
nitrogen and oxygen, then? I'd definitely be prepared to pay a
premium for that, rather than just using poxy air.

I've got some I can sell you. I'll send a boxful, ok?

The bottled stuff is so much better.
Adam

itd be cheaper if i posted you some condensed in an envelope-
just dilute it with air.

[ARWadsworth]

Post by george [dicegeorge]

Post by ARWadsworth

Post by Grimly Curmudgeon
We were somewhere around Barstow, on the edge of the desert, when
the drugs began to take hold. I remember Lobster

Post by Lobster
Cool. So where am I going to get my hands on this new wonder-mix of
nitrogen and oxygen, then? I'd definitely be prepared to pay a
premium for that, rather than just using poxy air.

I've got some I can sell you. I'll send a boxful, ok?

The bottled stuff is so much better.
Adam

itd be cheaper if i posted you some condensed in an envelope-
just dilute it with air.

Just stick it into a jiffy bag. If it leaks I can then empty the air pockets
of the packaging to save myself a few pence.

[Dave]

Post by Lobster

On Tue, 05 Oct 2010 17:49:23 +0100, Clive

Post by Clive George
They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.

Cool. So where am I going to get my hands on this new wonder-mix of
nitrogen and oxygen, then? I'd definitely be prepared to pay a premium
for that, rather than just using poxy air.

Any garage with a compressor. Here is a quote from the wikki

Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen.

Can you see what Kwik Fit are doing?

Dave

[ARWadsworth]

Post by Dave

Post by Lobster

On Tue, 05 Oct 2010 17:49:23 +0100, Clive

Post by Clive George
They're probably careful not to actually say that, because without
any qualification it's a lie. The improvements are comparing
correctly inflated tyres with underinflated ones, and it's
entirely possible to do that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a
byproduct of the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for
aircraft tyres, but that was to blow out any flames from when the
brakes used to explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to
explode like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years.
Nitrogen is completely safe. And by using it in a mixture with
oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.

Cool. So where am I going to get my hands on this new wonder-mix of
nitrogen and oxygen, then? I'd definitely be prepared to pay a
premium for that, rather than just using poxy air.

Any garage with a compressor. Here is a quote from the wikki
Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen.
Can you see what Kwik Fit are doing?
Dave

Errrrm.

I rather suspected that Lobster knew that:-)

[Dave]

Post by ARWadsworth

Post by Dave

Post by Lobster

On Tue, 05 Oct 2010 17:49:23 +0100, Clive

Post by Clive George
They're probably careful not to actually say that, because without
any qualification it's a lie. The improvements are comparing
correctly inflated tyres with underinflated ones, and it's
entirely possible to do that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a
byproduct of the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for
aircraft tyres, but that was to blow out any flames from when the
brakes used to explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to
explode like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years.
Nitrogen is completely safe. And by using it in a mixture with
oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.

Cool. So where am I going to get my hands on this new wonder-mix of
nitrogen and oxygen, then? I'd definitely be prepared to pay a
premium for that, rather than just using poxy air.

Any garage with a compressor. Here is a quote from the wikki
Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen.
Can you see what Kwik Fit are doing?
Dave

Errrrm.
I rather suspected that Lobster knew that:-)

So did I :-)

Dave

[Dave Liquorice]

Post by Andy Cap
FROM THE KWIK FIT SITE :-

<snip>

Post by Andy Cap
And by using it in a mixture with oxygen ...

Sounds bit like ordinary air to me?

Post by Andy Cap
to inflate your tyres the theory is that it s possible to negate the
issue of slow deflation, which is caused by oxygen slowly infusing
through the tyre wall from the atmosphere.

How can something coming into the tyre from outside cause deflation?

I've seen some completey wrong stuff in the past but that really does
take the biscuit.

[Dave]

Post by Dave Liquorice

Post by Andy Cap
FROM THE KWIK FIT SITE :-

<snip>

Post by Andy Cap
And by using it in a mixture with oxygen ...

Sounds bit like ordinary air to me?

Post by Andy Cap
to inflate your tyres the theory is that it s possible to negate the
issue of slow deflation, which is caused by oxygen slowly infusing
through the tyre wall from the atmosphere.

How can something coming into the tyre from outside cause deflation?
I've seen some completey wrong stuff in the past but that really does
take the biscuit.

The only time I have seen the wrong gas used to inflate things was when
I had the job as site supervisor at a primary school and the teachers
inflated balloons before they went home for a party the next morning,
When I opened up, all the balloons were very close to the floor because
helium passes through balloon rubber very easily.

Dave

[Alan Braggins]

Post by Dave
The only time I have seen the wrong gas used to inflate things was when
I had the job as site supervisor at a primary school and the teachers
inflated balloons before they went home for a party the next morning,
When I opened up, all the balloons were very close to the floor because
helium passes through balloon rubber very easily.

That's not so much the wrong gas as the wrong ballons or wrong time.
It's not as if you've got a wide choice of non-inflammable gases which
are significantly lighter than air and won't pass through balloon rubber.

[Andrew Gabriel]

Post by Dave
The only time I have seen the wrong gas used to inflate things was when
I had the job as site supervisor at a primary school and the teachers
inflated balloons before they went home for a party the next morning,
When I opened up, all the balloons were very close to the floor because
helium passes through balloon rubber very easily.

That's normal. Helium balloons normally last about 8 hours before
the helium has diffused out.

You might argue it's the wrong gas because we've almost run out of
helium and using what's left in balloons is a horrible waste of it.

[harry]

Post by Andrew Gabriel

Post by Dave
The only time I have seen the wrong gas used to inflate things was when
I had the job as site supervisor at a primary school and the teachers
inflated balloons before they went home for a party the next morning,
When I opened up, all the balloons were very close to the floor because
helium passes through balloon rubber very easily.

That's normal. Helium balloons normally last about 8 hours before
the helium has diffused out.
You might argue it's the wrong gas because we've almost run out of
helium and using what's left in balloons is a horrible waste of it.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Since helium is largely extracted from air it's merely being recycled.

[Dinky Earnshaw]

Post by harry

Post by Andrew Gabriel
You might argue it's the wrong gas because we've almost run out of
helium and using what's left in balloons is a horrible waste of it.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Since helium is largely extracted from air it's merely being recycled.

Actually, it's not. It's largely extracted from fossil fuel natural gas.

[Fred]

Post by harry
Since helium is largely extracted from air it's merely being recycled.

I thought that once but I'm not so sure now. I found this on a balloon
web site. Searching in google, the same text appears on a number of
balloon web sites so they must all be copying from the same source.
How correct that source is, I don't know. It says that helium is so
light that once in the atmosphere it keeps rising and rising and
escapes into space, and is lost from earth forever. It continues to
say that most helium is obtained from the radioactive decay of
uranium.

http://www.theballoonshop.co.uk/helium-facts-/info_8.html

says: "If you put helium in a balloon and let go of the balloon, the
balloon rises until it pops. When it pops, the helium that escapes has
no reason to stop -- it just keeps going and leaks out into space.
Therefore, in the atmosphere there is very little helium at any given
time. The helium that is there comes from alpha particles emitted by
radioactive decay..."

If helium is running out, I wonder how long before balloons are
outlawed? It's surprising that the balloon companies are so open and
honest about all this.

HTH

[Huge]

Post by Fred
If helium is running out, I wonder how long before balloons are
outlawed? It's surprising that the balloon companies are so open and
honest about all this.

http://arstechnica.com/science/news/2010/07/science-policy-gone-bad-may-mean-the-end-of-earths-helium.ars

[Jules Richardson]

Post by Fred

Post by harry
Since helium is largely extracted from air it's merely being recycled.

I thought that once but I'm not so sure now. I found this on a balloon
web site. Searching in google, the same text appears on a number of
balloon web sites so they must all be copying from the same source. How
correct that source is, I don't know. It says that helium is so light
that once in the atmosphere it keeps rising and rising and escapes into
space, and is lost from earth forever. It continues to say that most
helium is obtained from the radioactive decay of uranium.

The balloon fetishists are just looking for an excuse to turn the planet
into one giant balloon so we can go drifting off around the solar system.
Feckin' nutters, they are.

[Andy Dingley]

Post by harry
Since helium is largely extracted from air it's merely being recycled.

No, helium is stored in pork barrels.

It's an important story at present and yes, we're facing problems.

Helium is produced by radioactive decay in deep rocks. Then it mostly
escapes into space (slowly). However some geological structures, the
same salt domes that capture oil and gas, can trap it. So helium in
industrial quantities comes from a few oil and gas wells. In the
1920s, the USA was expanding both oil drilling and airship use, so
they saw a mutual benefit. Helium extracted in Texas was no longer
vented as waste, but was stored back underground as a Federal reserve.

A few years ago, the US decided to sell this reserve off very cheaply
(as a freebie to friends and family) meaning that helium is
unrealistically cheap at present and we're starting to see the bottom
of the barrel. At which point, superconductors will start becoming
very expensive and non-hydrogen airships thoroughly impractical.

[Andrew Gabriel]

Post by harry

Post by Andrew Gabriel

Post by Dave
The only time I have seen the wrong gas used to inflate things was when
I had the job as site supervisor at a primary school and the teachers
inflated balloons before they went home for a party the next morning,
When I opened up, all the balloons were very close to the floor because
helium passes through balloon rubber very easily.

That's normal. Helium balloons normally last about 8 hours before
the helium has diffused out.
You might argue it's the wrong gas because we've almost run out of
helium and using what's left in balloons is a horrible waste of it.

Since helium is largely extracted from air it's merely being recycled.

Helium released into the air is very quickly lost from the atmosphere
out into space forever, so it can't be recovered from there. What's
there is just in the process of leaking out through the earth's crust
on its way into space. We were using some mixed helium and natural gas
pockets which had got trapped in the crust (in Texas, I think), but
they're just about empty. There is a tiny amount which comes up in
some other oil and gas wells, which was passing through these reserves
on its way up through the crust. It's a by-product of nuclear decay
reactions deeper in the earth.

I did make enough hydroden to fill a balloon by electrolysis once, but
look where that got the Hindenburg.

[m***@privacy.net]

On 5 Oct,

Post by Dave Liquorice
I've seen some completey wrong stuff in the past but that really does
take the biscuit.

Try this one for a full packet!

<http://www.bestbrandtobuy.com/car-power-adapter/>

[harry]

On 5 Oct,  

Post by Dave Liquorice
I've seen some completey wrong stuff in the past but that really does
take the biscuit.

Try this one for a full packet!
<http://www.bestbrandtobuy.com/car-power-adapter/>
--
  B Thumbs
  Change lycos to yahoo to reply

American I think. They no education at all in America.

[Adrian C]

Post by harry
American I think. They no education at all in America.

Chinese Actually ...

Registrant:
Zhang Miaojiong
Baiguan
Shangyu, 312300
China

Domain Name: BESTBRANDTOBUY.COM
Created on: 13-Jan-09
Expires on: 13-Jan-14
Last Updated on: 28-Dec-09

Administrative Contact:
Miaojiong, Zhang
Baiguan
Shangyu, 312300
China
+86.13967530818 Fax --

Technical Contact:
Miaojiong, Zhang
Baiguan
Shangyu, 312300
China
+86.13967530818 Fax --

Domain servers in listed order:
NS1.TIGERTECH.NET
NS2.TIGERTECH.BIZ
NS3.TIGERTECH.ORG

[Ronald Raygun]

Post by Andy Cap
FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what
motor sport and aviation professionals have been doing for years. Nitrogen
is completely safe. And by using it in a mixture with oxygen to inflate
your tyres the theory is that ...

That sounds like exceptionally clever marketing. First they tell you
why nitrogen is good for your tyres, then they offer to sell you nitrogen
mixed with some oxygen. They don't say how much oxygen they've mixed in.

Could it be they're selling you just ordinary compressed air?
I wonder if their waiting room has a vending machine selling bottles
of Peckham Spring water.

[Andrew Gabriel]

Post by Andy Cap
FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.
Having a tyre that does not deflate means you will improve fuel consumption and
will probably improve safety standards too. It’s not yet standard practice but
Nitrogen could well be here to stay as a result. "

OK, I can just about make out some valid physics amongst the
bullshit.

If we assume there's no oxygen in the tyre, then an oxygen
molecule outside the tyre will see a vacuum inside the tyre.
The partial pressure of oxygen outside the tyre will be 20%
of air pressure (15 lb/sq.inch), i.e. 3 lb/sq.inch, so there
will be about 3 lb/sq.inch of pressure forcing oxygen to
diffuse in through the tyre.

Now consider the nitrogen. Assume the tyre is pumped up to, say,
30 lb/sq.inch nitrogen above air pressure, which is 45 lb/sq.inch
absolute. The partial pressure of nitrogen outside the tyre
will be 80% of 15 = 12 lb/sq.inch, so the net difference is
45 - 12 = 33 lb/sq.inch

So there's 3 lb/sq.inch of oxygen pressure outside the tyre
against 33 lb/sq.inch net of nitrogen pressure inside the tyre
(which by way of confirmation, cancels to give the 30 lb/sq.inch
observed tyre pressure). The ratio of the oxygen to nitrogen
pressures is 1:11.

Now, if the rate of diffusion of oxygen through the tyre is
more than 11 times the rate of diffusion of nitrogen through
the tyre, the pressure in the tyre will rise as more oxygen
will diffuse in, than nitrogen diffuses out.

So this boils down to the relative rate of diffusion of
Oxygen and Nitrogen through the tyre, and I don't know this
so I can only guess from now on. The two gasses are quite
similar in terms of molecule size, and I don't believe
that would cause a difference anywhere near 11:1. Oxygen
is potentially quite reactive, and there maybe some other
mechanism for getting it through the tyre if the molecule
can be pulled apart and reassembled by chemical reaction,
so it's actually the atoms diffusing through rather than
the molecule, whereas Nitrogen is less likely to have such
a mechanism, being more inert.

So it would be good to know what the mechanism at play here
really is.

If anyone has access to a nitrogen cylinder, it would be
interesting to blow up a balloon with pure nitrogen, seal,
and then see if it slowly gets bigger. (Need to cancel out
effects of size change due to temperature change.)
Diffusion through a balloon may not work same way as
diffusion through a tyre though, so it still won't
necessarily confirm or refute this theory. Also, diffusion
through the rubber may not be the primary mechanism and
certainly won't be the only mechanism for gas exchange
in/out of a tyre. Valve seals, rim seal, etc are also
potential candidates, and diffusion/leaks through these
may behave quite differently.

[Fredxx]

Post by Andrew Gabriel

Post by Andy Cap
FROM THE KWIK FIT SITE :-
" Nitrogen

So there's 3 lb/sq.inch of oxygen pressure outside the tyre
against 33 lb/sq.inch net of nitrogen pressure inside the tyre
(which by way of confirmation, cancels to give the 30 lb/sq.inch
observed tyre pressure). The ratio of the oxygen to nitrogen
pressures is 1:11.
Now, if the rate of diffusion of oxygen through the tyre is
more than 11 times the rate of diffusion of nitrogen through
the tyre, the pressure in the tyre will rise as more oxygen
will diffuse in, than nitrogen diffuses out.

I follow your calculations until you pull the ratio 11:1 Where do you get
the idea that oxygen diffuses through rubber 11 times as much as nitrogen?

[Andrew Gabriel]

Post by Fredxx

Post by Andrew Gabriel

Post by Andy Cap
FROM THE KWIK FIT SITE :-
" Nitrogen

So there's 3 lb/sq.inch of oxygen pressure outside the tyre
against 33 lb/sq.inch net of nitrogen pressure inside the tyre
(which by way of confirmation, cancels to give the 30 lb/sq.inch
observed tyre pressure). The ratio of the oxygen to nitrogen
pressures is 1:11.
Now, if the rate of diffusion of oxygen through the tyre is
more than 11 times the rate of diffusion of nitrogen through
the tyre, the pressure in the tyre will rise as more oxygen
will diffuse in, than nitrogen diffuses out.

I follow your calculations until you pull the ratio 11:1

That's the 33:3 ratio above.
So the nitrogen has 11 times more pressure on one side of
the tyre than the oxygen has on the other side of the tyre.

Post by Fredxx
Where do you get
the idea that oxygen diffuses through rubber 11 times as much as nitrogen?

I said that I've no idea if it is. It needs to be for this
theory to work. Frankly, I'd be surprised if it is.

[Dave]

Post by Andrew Gabriel
OK, I can just about make out some valid physics amongst the
bullshit.
If we assume there's no oxygen in the tyre, then an oxygen
molecule outside the tyre will see a vacuum inside the tyre.
The partial pressure of oxygen outside the tyre will be 20%
of air pressure (15 lb/sq.inch), i.e. 3 lb/sq.inch, so there
will be about 3 lb/sq.inch of pressure forcing oxygen to
diffuse in through the tyre.
Now consider the nitrogen. Assume the tyre is pumped up to, say,
30 lb/sq.inch nitrogen above air pressure, which is 45 lb/sq.inch
absolute. The partial pressure of nitrogen outside the tyre
will be 80% of 15 = 12 lb/sq.inch, so the net difference is
45 - 12 = 33 lb/sq.inch
So there's 3 lb/sq.inch of oxygen pressure outside the tyre
against 33 lb/sq.inch net of nitrogen pressure inside the tyre
(which by way of confirmation, cancels to give the 30 lb/sq.inch
observed tyre pressure). The ratio of the oxygen to nitrogen
pressures is 1:11.
Now, if the rate of diffusion of oxygen through the tyre is
more than 11 times the rate of diffusion of nitrogen through
the tyre, the pressure in the tyre will rise as more oxygen
will diffuse in, than nitrogen diffuses out.
So this boils down to the relative rate of diffusion of
Oxygen and Nitrogen through the tyre, and I don't know this
so I can only guess from now on. The two gasses are quite
similar in terms of molecule size, and I don't believe
that would cause a difference anywhere near 11:1. Oxygen
is potentially quite reactive, and there maybe some other
mechanism for getting it through the tyre if the molecule
can be pulled apart and reassembled by chemical reaction,
so it's actually the atoms diffusing through rather than
the molecule, whereas Nitrogen is less likely to have such
a mechanism, being more inert.
So it would be good to know what the mechanism at play here
really is.
If anyone has access to a nitrogen cylinder, it would be
interesting to blow up a balloon with pure nitrogen, seal,
and then see if it slowly gets bigger. (Need to cancel out
effects of size change due to temperature change.)
Diffusion through a balloon may not work same way as
diffusion through a tyre though, so it still won't
necessarily confirm or refute this theory. Also, diffusion
through the rubber may not be the primary mechanism and
certainly won't be the only mechanism for gas exchange
in/out of a tyre. Valve seals, rim seal, etc are also
potential candidates, and diffusion/leaks through these
may behave quite differently.

Aircraft tyres, inflated with nitrogen, do not increase in pressure.
They deflate just as if they had been filled with compressed air.
Unless you measure the pressure after landing when they become warmer,
just like you should never measure the pressure of your car tyres after
a long journey.

Your analogy is flawed. Atmospheric pressure is nominally about 15 PSI.
A tyre on a car is pressurised to 30 + PSI. No gaseous element cold
possible get into the tyre.

Dave

[Dave Liquorice]

Post by Dave
Your analogy is flawed. Atmospheric pressure is nominally about 15 PSI.
A tyre on a car is pressurised to 30 + PSI. No gaseous element cold
possible get into the tyre.

It's not as simple as just the pressure differential across the tyre.
If you have a two containers with different concentrations seperated
by something permiable the contents will even themselves out to equal
concentrations each side. Have a dig about for osmosis.

[Andy Dingley]

On 5 Oct, 17:56, Andy Cap <***@trashmail.net> wrote:

"by using it in a mixture with oxygen "

FFS! What sort of mixture do they use, 80/20?

[Chris Hogg]

Post by Andy Cap

Post by Clive George
They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.

Apart from the point raised elsewhere in this thread as to how
nitrogen, 'in a mixture with oxygen', differs from significantly from
air, I am at a loss to understand how oxygen is supposed to _infuse_
into a car tyre from the atmosphere against the obvious pressure
gradient, or why that should cause the tyre to slowly deflate, or why
filling the tyre with air enriched with nitrogen should prevent it
from happening, even assuming it does in the first place!

Post by Andy Cap
Having a tyre that does not deflate means you will improve fuel consumption and
will probably improve safety standards too. It’s not yet standard practice but
Nitrogen could well be here to stay as a result. "
Andy C

Graham's law of effusion is relevant here.
See http://en.wikipedia.org/wiki/Graham's_law . (For the purposes of
this situation, effusion can be approximately equated with diffusion).

Graham's law says that the ratio of the rates of diffusion for two
gases of differing molecular weights is inversely proportional to the
square root of the ratio of those molecular weights. For nitrogen and
oxygen, with molecular weights of 28 and 32 respectively, the ratio of
their diffusion rates is 1.069, which means that nitrogen diffuses
1.069 times faster than oxygen (say 7%). Lighter gases always diffuse
faster than heavier gases, which is why party balloons filled with
helium go flat faster than those filled with air.

OK, so the situation is made marginally more complicated by the fact
that the partial pressure of nitrogen in air is four times that of
oxygen, but that only serves to exaggerate the difference. A tyre
filled with nitrogen should lose pressure by diffusion _out_ through
the tyre wall faster than one filled with air, or one filled with
oxygen, for that matter. Perhaps they're using the wrong gas!

On a purely practical point and irrespective of theory, if nitrogen
and oxygen did, by some mechanism other than diffusion, pass through
rubber at significantly different rates, it would provide a very
convenient way of separating and thus concentrating them. Which,
AFAIK, isn't the case.

The Kwikfit claim would seem to be complete and utter rubbish. It
would be interesting to see what Trading Standards had to say on the
matter.

[Chris J Dixon]

Post by Chris Hogg
The Kwikfit claim would seem to be complete and utter rubbish. It
would be interesting to see what Trading Standards had to say on the
matter.

I enquired where the evidence was for the information on their
web site. They simply directed me to:

http://www.uniflate.com/

Chris

[Dave Baker]

Post by Chris J Dixon

Post by Chris Hogg
The Kwikfit claim would seem to be complete and utter rubbish. It
would be interesting to see what Trading Standards had to say on the
matter.

I enquired where the evidence was for the information on their
http://www.uniflate.com/

I always find it very hard to take the claims on a website seriously if the
people making the claims can't even spell or proof read their own site
properly. From the "Nitrogen Tyre Infation" cockup in large print at the top
right to various further errors in the text these people are clearly trying
quite hard to brand themselves as idiots.

As to tyre inflation with gases other than air in F1, I looked into this in
detail some years ago when it became apparent that Ferrari were doing
something different to other teams. Some of the details have since emerged
and there's a good article here.

http://forums.speedarena.com/showthread.php?3525542

The gases are actually a mixture of HFCs (hydroflourocarbons) and CO2 rather
than nitrogen and the aim is to conduct heat away from the tread faster and
keep it cooler rather than anything to do with molecules leaking in or out
which of course isn't going to be a remote issue over the course of a race.

[Dave Liquorice]

Post by Dave Baker

Post by Chris J Dixon
I enquired where the evidence was for the information on their
http://www.uniflate.com/

I always find it very hard to take the claims on a website seriously if
the people making the claims can't even spell or proof read their own
site properly. From the "Nitrogen Tyre Infation" cockup in large print
at the top right to various further errors in the text these people are
clearly trying quite hard to brand themselves as idiots.

And to sum up the content:

http://www.uniflate.com/benefits-of-nitrogen-tyre-inflation

Post by Dave Baker
By having your tyres at the correct pressures you will experience the
1. Better handling and road holding
2. Reduces tread wear and increases tyre life by up to 25%
3. Correct inflation pressures reduce puncture risk by up to 33%
4. Reduced rolling resistance improves miles per gallon by 2%
5. Improved pressure retention

So points 1-4 are all covered by just checking that tyres have the
correct pressure, which we all do don't we(*). Only point 5 can be
considered directly related to N2 filling.

(*) But I bet the vast majority of people don't, they just add fuel
when required and drive, servicing handed to garage as and when.
Backed up by the the Sussex Police survey where 73% of all cars
checked were 5 psi (+ or -) from the handbook pressure. If my tyres
get that far out I *really* notice it in the handling, indeed even a
couple of psi out is noticeable.

Trouble is the tyres checked in the survey would no doubt be hot as
the survey was a roadside one, pehaps that is why they had the +/-5
psi tolerance?

[Alan]

Post by Dave Liquorice
Trouble is the tyres checked in the survey would no doubt be hot as
the survey was a roadside one, pehaps that is why they had the +/-5
psi tolerance?

Judging by the poor state of the air machines at my local petrol
station(s) I'm not sure that anyone using them would have tyres
pressurised to within 5psi.

[John]

Post by Andy Cap

Post by Clive George
They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.
Having a tyre that does not deflate means you will improve fuel consumption and
will probably improve safety standards too. It’s not yet standard practice but
Nitrogen could well be here to stay as a result. "
Andy C

Since the atomic weight of Nitrogen is 7 and Oxygen is 8 and they both
have 2 atoms per molecule, the oxygen molecule is actually slightly
larger than the nitrogen one. Consequently, it will take longer to
diffuse through the tyre wall.

John

[dennis@home]

Post by John

On Tue, 05 Oct 2010 17:49:23 +0100, Clive George

Post by Clive George
They're probably careful not to actually say that, because without any
qualification it's a lie. The improvements are comparing correctly
inflated tyres with underinflated ones, and it's entirely possible to do
that with boring normal air.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Compressed nitrogen is _really_ cheap, being essentially a byproduct of
the oxygen business. They'd love you to use it.

Post by Camdor
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Sensible application there. Fortunately car brakes tend not to explode
like that :-)

FROM THE KWIK FIT SITE :-
" Nitrogen
Filling your tyres with nitrogen may seem odd but that’s exactly what motor
sport and aviation professionals have been doing for years. Nitrogen is
completely safe. And by using it in a mixture with oxygen to inflate your tyres
the theory is that it’s possible to negate the issue of slow deflation, which is
caused by oxygen slowly infusing through the tyre wall from the atmosphere.
Having a tyre that does not deflate means you will improve fuel consumption and
will probably improve safety standards too. It’s not yet standard practice but
Nitrogen could well be here to stay as a result. "
Andy C

Since the atomic weight of Nitrogen is 7 and Oxygen is 8 and they both
have 2 atoms per molecule, the oxygen molecule is actually slightly
larger than the nitrogen one. Consequently, it will take longer to
diffuse through the tyre wall.

Atomic and/or molecular mass alone do not determine size.

O2 has a double bond.
N2 has a triple bond.
Hence the size will be different as (apparently, its been decades since I
did any real chemistry) the triple bond is about 3% shorter than the double
bond.

[John]

Post by ***@home

Post by John
Since the atomic weight of Nitrogen is 7 and Oxygen is 8 and they both
have 2 atoms per molecule, the oxygen molecule is actually slightly
larger than the nitrogen one. Consequently, it will take longer to
diffuse through the tyre wall.

Atomic and/or molecular mass alone do not determine size.
O2 has a double bond.
N2 has a triple bond.
Hence the size will be different as (apparently, its been decades since I
did any real chemistry) the triple bond is about 3% shorter than the double
bond.- Hide quoted text -
- Show quoted text -

Sorry, I forgot that one.
It means that N2 will diffuse even faster than air then so we are
actually better off using air than N2 in our tyres.
Now if you want REAL fuel savings, go to solid tyres, preferably solid
metal. Just look at how ecconomical trains are.

John

[Richard Russell]

Post by John
It means that N2 will diffuse even faster than air then so we are
actually better off using air than N2 in our tyres.

Do you dismiss what it says here:

http://www.getnitrogen.org/savebillions/index.php

There are links to some of the original research documents, including
this from University of Bologna:

http://www.getnitrogen.org/pdf/ubologna.pdf

Richard.
http://www.rtrussell.co.uk/

[Tim Streater]

In article

Post by John
Now if you want REAL fuel savings, go to solid tyres, preferably solid
metal. Just look at how ecconomical trains are.

Is that why they need such a huge annual subsidy, then?

Some years ago I needed to go to Glasgow from Cambridge for a meeting.
Train was around �300, compared to �50 or so by whoever. To say nothing
of the extra time it would have taken.

I'm inclined to think that these plane/train "cost" comparisons don't
take the cost of the infrastructure and its maintenance into account.
Cost of the HS1 line again? Six billyun, was it? That's �100M per mile.

[Adrian]

Post by Camdor
Does this actually work?

To a certain degree, it stabilises pressures across wide heat ranges,
which is why it's used in aviation. F1 teams tend to use neat CO2 for the
same reason.

They also claim that the larger N2 molecules can't get through rubber by
osmosis, but since the tyres on my cars rarely loose even a single psi
from being fitted to being replaced, that's of dubious merit.

But if you bear in mind that "raw" air contains somewhere just shy of 80%
Nitrogen, you might get a hint of the - umm - applicability of
transferring those claims to road cars.

Post by Camdor
Noticed Kwik Fit are saying nitrogen extends tyre life by 25% and fuel
economy by 10%.

If you read the small print, they'll probably actually be saying that
having properly inflated tyres does that - which is blindingly obvious.

Post by Camdor
They are chargin £1.50 per tyre to inflate it with nitrogen.

Mmm. Do they mention how much it extends their profit margins by?

[ARWadsworth]

Post by Adrian

Post by Camdor
Does this actually work?

But if you bear in mind that "raw" air contains somewhere just shy of
80% Nitrogen, you might get a hint of the - umm - applicability of
transferring those claims to road cars.

Read the last paragraph:-)

http://www.kwik-fit.com/tyre-technology.asp

[Jim S]

Post by ARWadsworth

Post by Adrian

Post by Camdor
Does this actually work?

But if you bear in mind that "raw" air contains somewhere just shy of
80% Nitrogen, you might get a hint of the - umm - applicability of
transferring those claims to road cars.

Read the last paragraph:-)
http://www.kwik-fit.com/tyre-technology.asp

:o) I like the bit about mixing it with oxygen

[Dave Liquorice]

Post by Adrian
They also claim that the larger N2 molecules can't get through rubber by
osmosis, but since the tyres on my cars rarely loose even a single psi
from being fitted to being replaced, that's of dubious merit.

Mine vary with general ambient temperature, yes measured when cold,
but they are big tyres with a lot of air in them. At a guesstimate
I'd say 1.5 psi difference for every 10C change in temperature.

CostCo also offer Nitrogen filling, but as standard IIRC. They may
wibble about extending tyre life as without oxygen in the tyre it
can't degrade the rubber.

[Roger Chapman]

Post by Dave Liquorice
Mine vary with general ambient temperature, yes measured when cold,
but they are big tyres with a lot of air in them. At a guesstimate
I'd say 1.5 psi difference for every 10C change in temperature.

<sticks head above parapet>

Last time I ventured into the realms of half remembered basic physics I
managed to get something completely arse about face so take this with a
pinch of salt but it seems to me that 1.5 psi is rather too high.
Pressure is proportional to temperature so a 10C change in the ambient
should produce approximately 1 psi increase in pressure in a tyre at 30
psi and 300K.

<retires to bunker and waits for the brickbats>

[js.b1]

Alloy wheels above 16" can easily suffer air pressure loss at the bead
area due to corrosion or distortion from potholes.

Alloy wheel width matched to tyre width does seem to greatly increase
the number of slow punctures through the sidewall/25%-area. It seems
the "square" wheel-tyre width tends to make debris cause a puncture
rather than deflect. This is particularly true if driving too close to
gutters (out-in-out) or over debris strewn chevrons markings (eg, due
to roadworks or people parked on the phone). The phrase "puncture
magnet" is not inappropriate.

Would rather spend £1.50 replacing a tyre at a slightly higher tread
depth, or fitting tyre pressure alert caps.

[harry]

Post by js.b1
Alloy wheels above 16" can easily suffer air pressure loss at the bead
area due to corrosion or distortion from potholes.
Alloy wheel width matched to tyre width does seem to greatly increase
the number of slow punctures through the sidewall/25%-area. It seems
the "square" wheel-tyre width tends to make debris cause a puncture
rather than deflect. This is particularly true if driving too close to
gutters (out-in-out) or over debris strewn chevrons markings (eg, due
to roadworks or people parked on the phone). The phrase "puncture
magnet" is not inappropriate.
Would rather spend £1.50 replacing a tyre at a slightly higher tread
depth, or fitting tyre pressure alert caps.

I remember when alloy wheels first came out, air used to leak out
through the metal. Rectified with a coat of laquer inside the wheels.

[dennis@home]

Post by Roger Chapman
<retires to bunker and waits for the brickbats>

Why has the tyre got a propeller attached to it?

[Roger Chapman]

Post by ***@home

Post by Roger Chapman
<retires to bunker and waits for the brickbats>

Why has the tyre got a propeller attached to it?

Is that a brickbat I see before me?

But hey, how can you see my message to respond when you said only this
morning that you were going to "plonk" all the idiots who didn't agree
with you.

[dennis@home]

Post by Roger Chapman

Post by ***@home

Post by Roger Chapman
<retires to bunker and waits for the brickbats>

Why has the tyre got a propeller attached to it?

Is that a brickbat I see before me?
But hey, how can you see my message to respond when you said only this
morning that you were going to "plonk" all the idiots who didn't agree
with you.

Are you a free energy nut then?

I don't have anyone other than a few Chinese spammers in the killfile.
If i decide to ignore someone I just do that, I can see all TMH posts, I
just choose to ignore them.

[ARWadsworth]

Post by ***@home

Post by Roger Chapman

Post by ***@home

Post by Roger Chapman
<retires to bunker and waits for the brickbats>

Why has the tyre got a propeller attached to it?

Is that a brickbat I see before me?
But hey, how can you see my message to respond when you said only
this morning that you were going to "plonk" all the idiots who
didn't agree with you.

Are you a free energy nut then?
I don't have anyone other than a few Chinese spammers in the killfile.

You don't fancy the cheap handbags they offer then?

[Dave Liquorice]

Post by Roger Chapman

At a guesstimate I'd say 1.5 psi difference for every 10C change

in

Post by Roger Chapman

temperature.

Last time I ventured into the realms of half remembered basic physics I
managed to get something completely arse about face so take this with a
pinch of salt but it seems to me that 1.5 psi is rather too high.
Pressure is proportional to temperature so a 10C change in the ambient
should produce approximately 1 psi increase in pressure in a tyre at 30
psi and 300K.

My 1.5 psi is a guesstimate based on observation with only half
remembered over/under tyre pressures and only a vague knowledge of
the ambient temperature. If the physics says 1 psi/10C change that
indicates my guesstimate isn't too wide of the mark. Tyre pressures
should be 30 and 38 psi.

[Dave]

Post by Dave Liquorice

Post by Adrian
They also claim that the larger N2 molecules can't get through rubber by
osmosis, but since the tyres on my cars rarely loose even a single psi
from being fitted to being replaced, that's of dubious merit.

Mine vary with general ambient temperature, yes measured when cold,
but they are big tyres with a lot of air in them. At a guesstimate
I'd say 1.5 psi difference for every 10C change in temperature.
CostCo also offer Nitrogen filling, but as standard IIRC. They may
wibble about extending tyre life as without oxygen in the tyre it
can't degrade the rubber.

I always thought that the rubber deteriorated by contact with the road
and bad tacking.

Dave

[Roger Chapman]

Post by Dave
I always thought that the rubber deteriorated by contact with the road
and bad tacking.

Sailing too close to the wind? :-)

[dennis@home]

Post by Adrian

Post by Camdor
Does this actually work?

To a certain degree, it stabilises pressures across wide heat ranges,
which is why it's used in aviation. F1 teams tend to use neat CO2 for the
same reason.

Its just a gas the same as air, its not going to behave in a different way
at the temperatures tyres usually run at.

[newshound]

Post by ***@home

Post by Adrian

Post by Camdor
Does this actually work?

To a certain degree, it stabilises pressures across wide heat ranges,
which is why it's used in aviation. F1 teams tend to use neat CO2 for the
same reason.

Its just a gas the same as air, its not going to behave in a different way
at the temperatures tyres usually run at.

Except that oxygen will react chemically with rubber and cause it to
degrade, especially when it is warm (like an F1 tyre). I thought this was
the reason for not using air in F1 and aviation.

[Adrian]

Post by newshound
Except that oxygen will react chemically with rubber and cause it to
degrade

So how do they stop the outside of the tyre from "degrading"...?

[Jerry]

"newshound" <***@fairadsl.co.uk> wrote in message news:***@mid.individual.net...
:
:
: "***@home" <***@killspam.kicks-ass.net> wrote in message
: news:i8fsgo$r6e$***@news.datemas.de...
: >
: >
: > "Adrian" <***@gmail.com> wrote in message
: > news:***@mid.individual.net...
: >> Camdor <***@gmail.com> gurgled happily, sounding much
like they were
: >> saying:
: >>
: >>> Does this actually work?
: >>
: >> To a certain degree, it stabilises pressures across wide
heat ranges,
: >> which is why it's used in aviation. F1 teams tend to use
neat CO2 for the
: >> same reason.
: >
: > Its just a gas the same as air, its not going to behave in a
different way
: > at the temperatures tyres usually run at.
: >
: >
: Except that oxygen will react chemically with rubber and cause
it to
: degrade, especially when it is warm (like an F1 tyre). I
thought this was
: the reason for not using air in F1 and aviation.
:

Hardly going to matter in F1, those tyres have a very limited
life, certainly a lot lower than the rubber compounds used to
make the tyre when/if subjected to pure oxygen. As for aviation,
it's far more likely to be due to the fact that nitrogen is
inert.

[Man at B&Q]

Post by Camdor
Does this actually work? Noticed Kwik Fit are saying nitrogen extends
tyre life by 25% and fuel economy by 10%. They are chargin £1.50 per
tyre to inflate it with nitrogen.
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.
--
Regards
Camdor.

THey buy it form the Snake Oil Nitrogen Company.

It's bollocks.

MBQ

[The Natural Philosopher]

Post by Camdor
Does this actually work? Noticed Kwik Fit are saying nitrogen extends
tyre life by 25% and fuel economy by 10%. They are chargin £1.50 per
tyre to inflate it with nitrogen.
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

whose tyres decay before they wear out anyway?

My camper, yes on 3 toons at 300 miles a year..

But the sunlight got them anyway.

Sounds BS to me.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember The Natural Philosopher

Post by The Natural Philosopher
My camper, yes on 3 toons at 300 miles a year..

How very cosmopolitan.

[dennis@home]

Does this actually work? Noticed Kwik Fit are saying nitrogen extends tyre
life by 25% and fuel economy by 10%. They are chargin £1.50 per tyre to
inflate it with nitrogen.

Funny, the reason nitrogen is supposed to be better than air is because the
oxygen tends to leak through the tyre leaving an underinflated nitrogen
filled tyre.

If you actually check your tyres weekly it probably wont make any
difference, if you do it every year it might.

I wonder how they get the air out to fill it with nitrogen? Do they vacuum
pump it?

[Roger Chapman]

Post by ***@home

Post by Camdor
Does this actually work? Noticed Kwik Fit are saying nitrogen extends
tyre life by 25% and fuel economy by 10%. They are chargin £1.50 per
tyre to inflate it with nitrogen.

Funny, the reason nitrogen is supposed to be better than air is because
the oxygen tends to leak through the tyre leaving an underinflated
nitrogen filled tyre.

Andrew suggests that if you fill the tyre with N2 O2 will leak in.

Post by ***@home
If you actually check your tyres weekly it probably wont make any
difference, if you do it every year it might.
I wonder how they get the air out to fill it with nitrogen? Do they
vacuum pump it?

QF claim that they introduce some O2. Inflate a flat tyre with N2 and,
bingo, you get a tyre filled with N2 with added O2.

[Dave]

Post by ***@home

Post by Camdor
Does this actually work? Noticed Kwik Fit are saying nitrogen extends
tyre life by 25% and fuel economy by 10%. They are chargin £1.50 per
tyre to inflate it with nitrogen.

Funny, the reason nitrogen is supposed to be better than air is because
the oxygen tends to leak through the tyre leaving an underinflated
nitrogen filled tyre.
If you actually check your tyres weekly it probably wont make any
difference, if you do it every year it might.
I wonder how they get the air out to fill it with nitrogen? Do they
vacuum pump it?

Of the new cars I have bought, they all went from service to service
without needing oil in the engine, or air in the tyres.

Dave

[Peter Crosland]

Does this actually work? Noticed Kwik Fit are saying nitrogen extends tyre
life by 25% and fuel economy by 10%. They are chargin £1.50 per tyre to
inflate it with nitrogen.

Pure un-diluted bulls***! The crucial thing is to keep the pressures
correct.

Peter Crosland

[Andy Champ]

Post by Peter Crosland
Pure un-diluted bulls***! The crucial thing is to keep the pressures
correct.

Now I've fixed my computer (which is why I'm late to the party) let me
add my vote in favour of the BS thesis.

If oxygen really did go through the tyre faster than nitrogen wouldn't
it naturally concentrate inside anyway?

Andy

[Jerry]

"Camdor" <***@gmail.com> wrote in message news:RvIqo.49706$***@newsfe27.ams2...
: Does this actually work? Noticed Kwik Fit are saying nitrogen
extends
: tyre life by 25% and fuel economy by 10%. They are chargin
£1.50 per
: tyre to inflate it with nitrogen.
:

Total and utter con, an externally life expired tyre (such as
cracked side walls, cuts, or illegal tread depth) can look brand
spanking new on the inside when removed, think about it....

[Dave Liquorice]

Post by Jerry

Post by Camdor
Noticed Kwik Fit are saying nitrogen extends tyre life by 25% and

fuel

Post by Jerry

Post by Camdor
economy by 10%.

Total and utter con, an externally life expired tyre (such as
cracked side walls, cuts, or illegal tread depth) can look brand
spanking new on the inside when removed, think about it....

Looks aren't everything but yeah it's very close to the line. The ads
must have some small print that relate the quoted savings to
something in the real world.

Bit like the current Michelin tyre add ad that saves fuel. Up to 80l
on the life of the tyre, other small print on the ad gives the life
of a tyre as 28,000 miles. 80l saving, a single tank from 1,000, whoo
bloody who...

[Dave]

Post by Camdor
Does this actually work? Noticed Kwik Fit are saying nitrogen extends
tyre life by 25% and fuel economy by 10%. They are chargin £1.50 per
tyre to inflate it with nitrogen.
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

Not actually used to blow out the flames, but used so that the tyre gas
did not contain any oxygen that would fan the flames. I have worked on
fast jets (mainly Tornado development) for many years and the only time
they don't use nitrogen is when the crew are fed from a liquid oxygen
container for breathing.

Dave

[ARWadsworth]

Post by Dave

Post by Camdor
Does this actually work? Noticed Kwik Fit are saying nitrogen extends
tyre life by 25% and fuel economy by 10%. They are chargin £1.50 per
tyre to inflate it with nitrogen.
I remember when I was a Liney in the RAF, we used nitrogen for
aircraft tyres, but that was to blow out any flames from when the
brakes used to explode and rip through the tyres.

Not actually used to blow out the flames, but used so that the tyre
gas did not contain any oxygen that would fan the flames. I have
worked on fast jets (mainly Tornado development) for many years and
the only time they don't use nitrogen is when the crew are fed from a
liquid oxygen container for breathing.
Dave

I was lead to believe that any dry air mixture would be fine for aircraft
tyres. As long as there was no possibility of ice forming inside the tyre at
altitude was what mattered.

[Halmyre]

Post by Camdor
Does this actually work? Noticed Kwik Fit are saying nitrogen extends
tyre life by 25% and fuel economy by 10%. They are chargin £1.50 per
tyre to inflate it with nitrogen.
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

I always insist on hydrogen filled tyres. The reduction in weight does
wonders for my fuel consumption, but it makes the handling a bit
tricky.

--
Halmyre

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Halmyre

Post by Halmyre
I always insist on hydrogen filled tyres. The reduction in weight does
wonders for my fuel consumption, but it makes the handling a bit
tricky.

Oh, the humanity...

You should use some Helium before it all goes away.

[Dave]

Post by Grimly Curmudgeon
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Halmyre

Post by Halmyre
I always insist on hydrogen filled tyres. The reduction in weight does
wonders for my fuel consumption, but it makes the handling a bit
tricky.

Oh, the humanity...
You should use some Helium before it all goes away.

What? And re inflate them every morning?

Dave

[Halmyre]

Post by Grimly Curmudgeon
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I rememberHalmyre

Post by Halmyre
I always insist on hydrogen filled tyres. The reduction in weight does
wonders for my fuel consumption, but it makes the handling a bit
tricky.

Oh, the humanity...
You should use some Helium before it all goes away.

You fool! Helium is four times heavier than hydrogen. I don't want to
use four times as much petrol!

--
Halmyre

[Andy Champ]

On 08/10/2010 09:08, Halmyre wrote:
.

Post by Halmyre
You fool! Helium is four times heavier than hydrogen. I don't want to
use four times as much petrol!
--
Halmyre

Twice actually. H2 molecules vs He atoms. :P

Andy

[Halmyre]

Post by Andy Champ
.

Post by Halmyre
You fool! Helium is four times heavier than hydrogen. I don't want to
use four times as much petrol!
--
Halmyre

Twice actually. H2 molecules vs He atoms. :P

Damn you and your extensive knowledge of chemistry.

[Andy Dingley]

Post by Halmyre
You fool! Helium is four times heavier than hydrogen. I don't want to
use four times as much petrol!

Twice actually.  H2 molecules vs He atoms. :P

This is Usenet. We have plentiful reserves of monomoronic hydrogen
over in alt.energy.free.browns-gas

[Reentrant]

.

Post by Halmyre
You fool! Helium is four times heavier than hydrogen. I don't want to
use four times as much petrol!
--
Halmyre

Twice actually. H2 molecules vs He atoms. :P
Andy

But the buoyancy of hydrogen is only 8% greater than helium

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

[Andy Dingley]

Post by Reentrant

Twice actually. H2 molecules vs He atoms. :P

But the buoyancy of hydrogen is only 8% greater than helium

Buoyancy here has more to do with the weight of what you're displacing
(considerably more) than the H /He difference. Even vacuum isn't
hugely better.

[Tim Streater]

In article

Post by Andy Dingley

Post by Reentrant

Twice actually. H2 molecules vs He atoms. :P

But the buoyancy of hydrogen is only 8% greater than helium

Buoyancy here has more to do with the weight of what you're displacing
(considerably more) than the H /He difference. Even vacuum isn't
hugely better.

:-)

Amazing how many folks think that H/He/hot air gives you lift, innit,
when its actually gravity.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Halmyre

Post by Halmyre
You fool! Helium is four times heavier than hydrogen. I don't want to
use four times as much petrol!

Well, just be careful when docking it.

[Reentrant]

Post by Camdor
Does this actually work? Noticed Kwik Fit are saying nitrogen extends
tyre life by 25% and fuel economy by 10%. They are chargin £1.50 per
tyre to inflate it with nitrogen.
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

It would have been the end of James Bond in "A View to a Kill".

[Dave]

Post by Reentrant

Post by Camdor
Does this actually work? Noticed Kwik Fit are saying nitrogen extends
tyre life by 25% and fuel economy by 10%. They are chargin £1.50 per
tyre to inflate it with nitrogen.
I remember when I was a Liney in the RAF, we used nitrogen for aircraft
tyres, but that was to blow out any flames from when the brakes used to
explode and rip through the tyres.

It would have been the end of James Bond in "A View to a Kill".

I also wonder if he was ever told not to approach a wheel from the side,
in case it exploded. In the event of a heavy landing, the brakes could
be so hot as to cause the bolted together wheels to explode and kill you.

Dave