# Nitrogen in tires???



## MacDoc (Nov 3, 2001)

Saw an ad for nitrogen fillups. $39 one time and they keep it topped up.

I suspect this would save millions of gallons of fuel if it was mandated.
Anyone have any experience with it.

I would have jumped as I'm bad at keeping pressure right and apparently nitrogen does not leak through as air does.
I'm due for new tires tho so I'll wait.

Feedback?? There seems to be some controversy.

http://www.getnitrogen.org/sub2.php?view=print


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## SINC (Feb 16, 2001)

Here's an interesting site with a calculator to see if you save using nitrogen in _your_ vehicle:

http://www.getnitrogen.org/?gclid=COOrif60g4sCFQluIgodNiBwGA


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## Macfury (Feb 3, 2006)

As long as using this in one's tires result sin a nitrogen-neutral lifeystyle, I'm all for it.


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## rgray (Feb 15, 2005)

Air is something like 80% nitrogen anyway, if i remember correctly from chem class. Really you are only dealing with 20% of the capacity.

The theory behind using pure nitrogen in tyres is that bigger molecules leak less.

What do you do if you travel a lot? Do you have to keep track of nitrogen stations like us old guys have to keep track of (clean) restrooms? What are the consequences of topping off with regular old-fashioned air?

Adjusting tyre pressure is not always adding 'air'. As the weather heats up, you have to let off pressure - this can sometime be quite dramatic from winter to spring...

Seems to me to be a lot of hoo-hah and a way for retailers to extract another $40+/-.

How does one *KNOW* that what is being put in is actually pure nitrogen? Seems to me that there is room here for ripoff.


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## Moscool (Jun 8, 2003)

Reminds me of an old TV investigation on the power of marketing that said in substance:

"No matter how marginal your product, given the size of the US market, there will always be somebody somewhere to purchase it or endorse it. In the rest of the world if your bum itches, you scratch it or you wash it. In America we have a cream."

If you can't be bothered to check the air in your tyres regularly, then you are probably also neglecting other aspects of car safety. LEt me ride with somebody else...


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## Macfury (Feb 3, 2006)

rgray said:


> Air is something like 80% nitrogen anyway, if i remember correctly from chem class. Really you are only dealing with 20% of the capacity.


Bah! Similar arguments were once made about carbon dioxide. You'll rue the day....


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## MacDoc (Nov 3, 2001)

Other safety aspects - for instance??  What a dubious conclusion jump. I'm a pilot I know about safety checks.

The cost calculator showed a savings about $227 per year.
It's my understanding that it's oxygen content and moisture that is the main factor in this.
I think I'll get it with new tires as indicators are you can negotiate it as a throw in and it's super dry compared to an air fillup.
Arthritis makes tire checking a literal pain for me and I use synthetic oil at 10k intervals which is too long between checks.
The gauges at stations are pretty marginal to useless.
I do have a small compressor that takes forever but seems decently accurate.

Rather than idle speculation which seems a popular past time has anyone actually used nitrogen?

The key seems to be "dry" - but how does one assure dry air.?? A free or very low cost nitrogen fix with free top offs would seem "no harm". We run our vehicles well up into the hundreds of thousands of KM so it should pay for us.


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## Macfury (Feb 3, 2006)

I have heard local commercials from tire dealerships in Western NY offering free nitrogen with tire purchase as a sales incentive.

Whether there were real benefits or not, it would certainly be a good gimmick to get people to return to the dealership frequently. I can't imagine nitrogen gas to be a huge expense.


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## MacDoc (Nov 3, 2001)

Yeah I think it's a return incentive and clearly the "no moisture" aspect has merit if nothing else.

Slightly related topic - there was a lot of talk about very high mileage compounds a couple of years back offering extremely long tire life and good mileage.

Is that the norm now? Be a nice combination to put on with a nitrogen fill.

When prices got really high there I did a small test with upping the tire pressure to 35 and keeping speeds to 100k and driving very efficiently - got a pretty solid 4-5 mpg bump ( 20-25% ) but was it boooring.


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## rgray (Feb 15, 2005)

Here is my essay (some night say rant) on this subject, based on years of rallying, racing and being a general gear-head all my life.

First of all, we are not talking about leakage due to marginal valves, bead seating, ultra-violet degredation or any other issue like that. Tyres are not 100% airtight - you can expect up to about 1 lb loss in a month with the very best fresh tyres. The 'rubber' is actually very slightly porous.

The nitrogen theory suggests that bigger molecules will seep less. Given that air is about 80% nitrogen anyway, and assuming the big molecule theory to be true, then one can expect the seepage to be molecules smaller than nitrogen. Theoretically then it follows that the concentration of nitrogen in your tyres is actually slowly going up as you maintain the pressure, as other components of air seep away more easily.

Anything that takes away from regular inspection of tyre pressure also makes it less likely that one will inspect other aspects of tyre life such as tread wear, partial abrasions, objects stuck in the tread (nails) and so on. While testing tyres you also get to notice things like drips and leaks in other systems (brakes!).

Variations in tyre pressure bear dramatically on tyre life. Under inflated tyres overheat and wear more quickly at the edges. Overheating degrades the 'rubber' causing premature failure which can be as dramatic as a blowout - at speed, blowouts are no fun at all. Over inflation causes tyres to wear in the centre resulting in premature failure and reduce traction particularly in the rain. So there is motivation, particularly at the price of *quality* tyres these days, to keep track of pressure.

That said there is no magic in the pressures listed on the sticker on the door post or in the owners manual. Strictly speaking those pressures apply only to the type of tyre that comes on the car stock and at a particular load level. They may not be optimal if you have changed tyre type or if your usual load is different from the specification.

To find the proper pressure, one makes a chalk mark right acros the tread, drives a bit and examines it. If the chalk line thins first in the centre, let off a little air and test again. If it thins first at the edges, add a little. Continue until the chalk line wears evenly. Note that on a race car, as little as 1/4lb can dramatically change the personality of the car and it is not all that different on the road.

Having survived blowouts at the track, I am extremely hot on tyre safety. I never want to experience that on a busy highway. I don't keep tyres on a car beyond half the tread depth and I test them at least once a week.

If you don't keep track of your tyre pressures (as someone else said above) I won't ride with you. Failure to maintain tyre pressure is symptomatic of failure to regard other aspect of safety (which has also been stated above). You cannot do a decent job of testing pressure if you have to haul your ass to the nitrogen depot every time you need a change (weekly).

The alleged savings in the table linked above are largely attributable to maintaining pressure, NOT to nitrogen itself.

Nitrogen in your tyres, just like driving a Lincoln Masterbator, does NOT give you bigger 'nads.


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## MacDoc (Nov 3, 2001)

You did not address the "dry air" aspect.

YOu may be fanatical about your tires and act on it- the greater public is not and there is little ease of doing so.

Given the importance,I agree with btw, for safety, mileage, tread wear etc you'd think there would be a "better way" than the stuff available at gas stations.

I noticed the insurance industry had those "cracked glass" safety stations that employed students to provide quick fixes for free for small windshield cracks.

Seems to me a program akin to that might be useful.
The problem arises in that it's against the interest of gas stations for you to get better gas mileage and longer tire life. So they provide minimal attention to it.

How to resolve that inherent conflict??


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## Macfury (Feb 3, 2006)

MacDoc said:


> The problem arises in that it's against the interest of gas stations for you to get better gas mileage and longer tire life. So they provide minimal attention to it.
> 
> How to resolve that inherent conflict??


I don't think they take it that far--otherwise they wouldn't even provide air pumps. If they thought they could increase market share by offering a nitrogen pump they would do so, and increased mileage be damned.


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## rgray (Feb 15, 2005)

MacDoc said:


> You did not address the "dry air" aspect.


I'm not sure the 'dry air' issue is any more real than the whole nitrogen dog 'n' pony show.

EDIT: Many compressors have moisture removal systems - moisture is 'bad' in many compressed air applications and to the internals of the compressor.


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## MacDoc (Nov 3, 2001)

Yeah but do you really believe the junk at the gas stations fall into that category??


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## rgray (Feb 15, 2005)

MacDoc said:


> Yeah but do you really believe the junk at the gas stations fall into that category??


Let me answer your question with a question: do you really believe that, should nitrogen systems become common, that they would be any better maintained than the currently ubiquitous air systems?

Seems like the answer to your question and mine is "No".

As ever was and evermore will be: caveat emptor


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## MacDoc (Nov 3, 2001)

Since nitrogen is generally available in a tanked system my answer is yes - it would be drier.
I also think if it's a "for pay" system as it appears to be now in most areas ( it's not mandated I'm told ) then at the very least getting value for money in terms of dry air might be expected.
I would guess a tanked nitrogen system woud indeed be drier than a cheap open air compressor which is there now and often needs to be paid for.

I can't afford to by a commercial grade "dry" compressor - where am I supposed to get dry air??
A fillup from a nitrogen tank at a small fee seems to be a reasonable approach.

••

Also as the polluter pays idea hits and the cost of fuel rises I would say tire pressure will become a major factor ( it is already but is ignored ).
I would think it will become part of a lower energy use regime.


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## Gunner (Sep 8, 2003)

If you buy your tires from Costco they add Nitrogen at no cost. If they do any service on your car they will swap out the air for nitrogen at no cost. I just had an oil change there about a month ago and they did the swap for me. Now all I need to do is pull up to the Costco garage if I ever need to adjust the pressure. Is is better than air? I can't answer that one.


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## guytoronto (Jun 25, 2005)

Good grief, this has got to be the most ridiculous thread today.

Normally intelligent people debating the aspects of "air quality" in tires.

Calculating the "cost effectiveness" of "100% nitrogen"?

Good grief. Pick up a $5 air pressure gauge at Canadian Tire, check your tires weekly, top up when necessary, and stop being so silly.


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## rgray (Feb 15, 2005)

Interesting about Costco.

And thinking this through a bit further, even tho' I am not sold on the idea of nitrogen _per se_, I did have a further tho't on ease of use. I do not use a compressor for air supply to adjust tyres, at least not directly. The low priced compressors are crap and one doesn't need a bigger one just to mess with tyres. I got one of those portable air cylinders which I charge up at a known-good source of air (a compressor that I know to be set up with moisture remover, etc.). Then I use the tank to maintain tyres and for a bunch of other tasks. One could just as easily have a portable nitrogen tank for the tyre purpose that would negate many of my criticisms..... Hmmm...


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## rgray (Feb 15, 2005)

guytoronto said:


> Good grief, this has got to be the most ridiculous thread today.
> 
> Normally intelligent people debating the aspects of "air quality" in tires.
> 
> ...


Hey! We're enjoying a semi-theoretical debate here so back off.  

Nobody (as far as I know) has tied you up (which might be enjoyable in other contexts) and forced you to read this thread....


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## CanadaRAM (Jul 24, 2005)

It's a canard.

The savings (gas and tire life) calculated are not as a result of using N2, they are a result of proper inflation, no matter what the gas used. You would get equal savings from proper inflation with air. 

The argument that 100% N2 will lose pressure slower than 78% N2 is weak.

The worst case scenario assuming perfect N2 retention, no rim seal or valve stem loss, and loss of *all* O2 (CO2 being larger than N2, IIRC) would be a drop in pressure from 35 psi to 28 psi. Not ideal but not tragic either.
The assumptions that all O2 and no N2 would be lost, and that losses throughthe rubber are the only type of loss are completely unsupportable however.

This is like advertising for vitamin elixers. Start with the premise that your diet is so bad that you're vitamin deficient and will get ricketts, scurvy and according to the Vitamin calculator you'll die 20 years early and lose $2 million.

Then advance the notion that the only way to get the proper diet is with Dr,. Nitrogen's Vitamin Juice at only $39

Both parts of the argument are false. The condition is not at worst case, and the cure is not the only way to reverse it. There are simpler and cheaper ways to 'save' the situation.


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## rgray (Feb 15, 2005)

Well said... Much better than my rambling verbose rant, althought the point is the same.



CanadaRAM said:


> It's a canard.
> 
> The savings (gas and tire life) calculated are not as a result of using N2, they are a result of proper inflation, no matter what the gas used. You would get equal savings from proper inflation with air.
> 
> ...


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## MacDoc (Nov 3, 2001)

Okay accept the nitorgen over "good air" as a moot point I I thnk Rgray is getting there )

He said 


> Then I use the tank to maintain tyres and for a bunch of other tasks. One could just as easily have a portable nitrogen tank for the tyre purpose that would negate many of my criticisms..... Hmmm...


Now he is getting good dry air but how many others with go to that length??
We pretty much KNOW we can't get good dry air from the local compressor.

My rationale is that nitrogen from a tank free or at low cost is likely the best method for those not prepared to go to Mr Gray's lengths to achieve a similar result.

I also don't consider it minor as it's an big factor in mileage, tire life/wear and safety. If a nitrogen fix helps get "good dry air" - why not.


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## rgray (Feb 15, 2005)

Why not, indeed...  

Having that portable air tank has not proved to be such a "length". The thing has proved useful for a lot of tasks where a little compressed air is useful, not the least blowing out dust. also, small spray and airbrush jobs... Like I said. I'm a gearhead. Tools are fun.


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## MacDoc (Nov 3, 2001)

And your honest assessment of the percentage of drivers who would undertake that effort ?


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## rgray (Feb 15, 2005)

MacDoc said:


> And your honest assessment of the percentage of drivers who would undertake that effort ?


At a guess, very small. I would hope other drivers would follow the dictates of their own intelligence, which is no concern of mine. I have never been accused of succumbing to peer pressure...


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## MacGYVER (Apr 15, 2005)

I don't see the point of using Nitrogen in tires if you're driving a vehicle. It doesn't have any benefits that I can see from a vehicles point.

You all know that aircraft tires are filled with Nitrogen right? They are not filled with compressed air. The reason for that is, if they landed with just air in their tires, the tires would explode on impact while landing. Nitrogen is more how should I put it for an aircraft "flexible" inside of the tire at altitudes and landing, therefore I really don't see any benefits in a regular vehicle on a road using nitrogen versus regular compressed air. Who knows, maybe there is some scientific data out there to say otherwise?


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## MacDoc (Nov 3, 2001)

I would appear the only real point for the everyday driver is to achieve low moisture content which DOES have benefits since dry compressor air is iffy to find.
Why not if it's free or very low cost and top ups
Heavy trucks apparently use nitrogen as well.

I guess what I'm dismayed with is the lack of ease to get accurate readings and dry air given the importance.

Wonder what the insurance company stats might be on tire problems as accident contributors.


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## Gerbill (Jul 1, 2003)

The only instance of nitrogen in tires in my personal experience was years ago when I worked at TransAir in Winnipeg - they used nitrogen in the aircraft tires.


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## gordguide (Jan 13, 2001)

Sounds expensive, MacDoc. I've always used Nitrogen gas as a propellant for my airbrush, (quiet, cheap, and 100% moisture free; water cannot exist in a nitrogen environment). It's been a while since I had a refill, but I think I remember paying $15 or so for a 100# bottle fill at the compressed gas store (and that was during an illegal price fixing conspiracy).

I also have a buddy who is an organic farmer, and he often travels to the shipyard to check the railcars holding his grain before they're graded and loaded to wherever they're going (usually England). They often pick up insects along rail sidings, etc, and that can take a $10/bushel crop down to $3. He seals the cars with vapor barrier and duct tape, and slowly dumps a 100# bottle of Nitrogen in there, holding it for 48 hours. Kills every bug, which is then screened out. He gets zero dockage (dead bugs are OK, live ones not OK, but he can't use pesticides like everyone else can) and top grade for his crop. (Insects' metabolism is regulated by Nitrogen content; the little guys hyperventilate, their whole lives run at triple time, and they die before they have time to lay eggs).

$60 for a regulator and something for a deposit on the bottle, and you could do a lot of cars before you would need a refill. It looks like these guys are using the Nitrogen machines (rather than compressed gas) that are expensive ($US 7,000 ~ 12,000) and need to be paid for, but require no maintenance and once paid for, it's something like 80% profit, at least according to the manufacturers.

Having said that, air is free and checking air pressure in your tires is all you need to do. I've always used Nitrogen because I have a bottle of it in my shop, no moisture is always better than some moisture when it comes to your vehicle, but I wouldn't pay for it just for my tires.

I'm not sure about it leaching through the rubber less, but moisture in tires is a big cause of pressure rise with tire heating (highway driving) and Nitrogen is much more temperature stable. Water freezing in the tire valve is a big hassle in winter and gives a lot of grief if you try to maintain proper inflation during sub-zero temps. In the summer not so much, but it might run cooler and therefore prolong tire life or reduce the incidence of heat-related failure.

Racers use it for temperature stability; they need repeatable inflation pressures and air just changes too much between hot and cold to be useful as an indication of tire patch (because of variable moisture content). But, racers also measure tire temps with probes into the tread itself, and then have charts to refer to that are based on real-world measurements of tire patch, axle weight, inflation pressure and tire temperature, and racers spend thousands on tires sometimes just for one race. Not really applicable on your street tire.

Aircraft use it for similar reasons; moisture causes more expansion and temperature rise and they can blow out, which, if it only costs you money, is considered lucky. Still, airplane tires and road vehicle tires have little in common beyond a tendency toward roundness.

If you are thinking of it being a substitute for checking tire pressure, well, I say save your money, or else buy some of the valve stem covers that directly read pressure (you buy the one that indicates your correct pressure within a narrow pressure range) and can be read at a glance just by looking as you get in the car, or if you want hi-tech, a direct reading pressure monitor system. Remember, " ... The US Department of Energy estimates that we could save two million gallons of gasoline every day if our tires were properly inflated. ..." * does not mention Nitrogen, it mentions proper inflation.

Just a note for anyone considering using Nitrogen as a paint gas: it displaces oxygen and you need a supply of fresh air, or you can asphyxiate. Just so you know.

* Blurb from the company that makes the turn-key machines.


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## MacDoc (Nov 3, 2001)

> If you are thinking of it being a substitute for checking tire pressure, well, I say save your money, or else buy some of the valve stem covers that directly read pressure and pop out when it's wrong. You can tell at a glance if you need more pressure just by looking as you get in the car


Now that's a great idea - anything to look for in particular.??

As for cost - I think I mentioned "free" several times as good. 
If Costco or others use to as a come on to buy their tires etc or I have to pay a one time fee of $10 a tire and free top ups that's worthwhile for me.

Clearly it's the "dry" aspect that's most critical for tire life. I assume pure nitrogen = no water vapour by definition - whether bottled or extracted on the spot by a machine.

Anybody comment on the "long life" compounds?? Recommendations ( van tires ).


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## MACSPECTRUM (Oct 31, 2002)

MacDoc said:


> Now that's a great idea - anything to look for in particular.??



tire stems that indicate tire pressure

something i never knew about but am going to buy asap
i have lots of problems with low tire pressure during the winter months, especially when the very cold weather comes around

i found this company in canada and they sell their stuff thru Canadian Tire

http://www.minderresearch.com/tireminder.html

or to order direct - caps come in small range of pressure - check your tire recommended tire pressure before you buy
http://www.tireminder.ca/

here is what cdn. tire carries


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## guytoronto (Jun 25, 2005)

http://www.straightdope.com/columns/070216.html

Unless you live beside Costco to get your free "top-ups", doing this nitrogen only thing is completely stupid.

The cost involved, having to travel extra distance for the top-up, no tangible benefits. Great! Now we have more cares burning gas just to get to Costco to get their free nitrogen.

Hmmm....Costco offers free top-ups? Sounds like a marketing ploy to get you into their stores. Nah! That couldn't be it.

They say there's a sucker born every minute. Costco calls that customer base growth.


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## spicyapple (Aug 17, 2006)

Now if they can only fill tires up with helium, thereby making the car lighter and thus saves gas because of reduced curb weight.


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## MacDoc (Nov 3, 2001)

Well as it happens I do live very near a Costco - it's right on the way to my son's school and apparently they are not the only ones that will offer it.

One has to "drive" to a service station anyway - hardly a great argument and service station air is marginal at best and inaccurate to a large degree I'd prefer the dry condition nitrogen offers.

Of course it's a come on - why does that automatically make it a "bad thing".
Some 10% of tire dealers offer nitrogen.


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## rgray (Feb 15, 2005)

The Wheel and Tyre Bible has a ton of information on, umm, wheels and tyres... more than most people need to know.

Interestingly nitrogen is not even mentioned. 

However, germain to the current discussion is a section at the bottom of the 'paper' on TPMS (Tyre Pressure Monitoring Systems). The popup valve stem covers are merely the tip of the proverbial iceberg with options including replacement valves that measure the full range of pressure (not just sensitive in a narrow range) and connect wirelessly to a small monitor on the dash:

View attachment 2913


EDIT: Fixed image.


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