Nitrogen Tire Scam part 3

Okay, I thought of adding this response as a comment, but since it ended up being so lengthy, I decided to make a separate post. The original comment is here and was caught by the Akismet as spam. I’ve since approved it to be visible.

A response to John Lucidi

First, I’d like to mention that your post was caught in my spam filter (Akismet) due to the number of links you included, so it wasn’t a matter of my not wanting your comment to appear. I just don’t look at posts caught by Akismet very often since it’s almost always pure, unadulterated spam. I have, I believe, read your comment posted on other sites, so one could make an argument that copy/paste behavior by someone who admits an interest in an industry’s success is actually spam. Indeed, I hold that it is.

Nevertheless, I’m willing to approve the comment if only to address the points you’ve made for public record.

The first thing I noticed in your comment was that the Bridgestone link [PDF] was actually to a marketing pamphlet hosted on your own site rather than an actual independent study or measurement as you claim. I contend that Bridgestone has a financial interest in the “nitrogen-filled tire” industry, and note that this pamphlet is not available on their domain. In fact, the only mention of nitrogen in tires I could locate was this quote:

Because race tires are subject to much higher operating temperatures, the air to inflate them is filtered to remove moisture. Moisture inside a race tire could become steam, creating potential problems. Most teams actually replace this filtered air with nitrogen.

My contention that Bridgestone has a financial interest is largely based on the web address included on the marketing pamphlet which is to http://www.trucktires.com and they doubtless have either an affiliation with or provide their own nitrogen filling service for over the road truckers. Big rig trucks have tires that include far more sidewall rubber surface and larger volumes of gas within, and the tires are subjected to wear and use that far exceeds that of the average commuter, so it may actually be that there have been studies done on OTR truck tires that reveal a benefit to having nitrogen-filled tires.

But this doesn’t relate or equate to any benefit to having nitrogen -filled tires on a passenger car. If we concede for a moment (and I’m not actually doing so without seeing an independent study that isn’t a marketing brochure for a company attempting to make a buck) that there is a benefit, which outweighs the exorbitant cost, for OTR truckers to have nitrogen-filled tires, it still must be considered that the tire of a truck has a far greater surface area of sidewall rubber and a larger volume of gas within which may actually create faster rates of diffusion for both gas molecules. There are more molecules and more available avenues of egress.

So, your “proof” isn’t actually proof of anything other than the fact that Bridgestone Firestone has an affiliation or at least some sort of interest in nitrogen-filled tires for OTR trucks. I saw no mention in this marketing pamphlet (your “proof”) that referenced an independent study.

There is, however, an independent study conducted by consumer reports that was conducted on passenger car tires. Their results showed that in one year nitrogen-filled tires lost 2.2 psi while tires filled with normal air mix lost 3.5 psi. This is a difference of 1.3 psi over a full year and certainly nothing close to 4 to 6 times “faster than nitrogen.” I also found it interesting that you’re quick to mention that rate as are many other advocates of this expensive and unnecessary method of filling tires, but never is the rate itself defined. What are the units measured over what period of time? Moreover, the Consumer Reports study also demonstrates that both molecules are diffused over time, with nitrogen diffusing at a slightly slower rate, which is something that I readily conceded to in my initial post.

With regard to tire wear from chemical aging, I’ve again conceded that pure, nitrogen would halt this. From the inside! Surely you realize that oxygen and moisture in the air outside the tire can and will permeate the side wall of a tire. Normal atmospheric pressure, after all, is still a pressure and the molecules of O2 and H2O are variable excited depending upon pressure and temperature and will collide with the same rubber sidewalls from the opposite side. Fortunately, this isn’t a concern since chemical wear, for the average commuter, occurs at a rate that is far slower than physical wear. I have yet to replace a set of tires due to chemical aging -inside or out. I realize I can’t speak for you, but I’m willing to bet $5.00 via Paypal that I can find an independent source that shows the most common reason for tire replacement is worn tread.

You say that “[i]t is a well proven fact within the tire industry that nitrogen inflated tires maintain their pressure better than air filled tires.” I don’t deny this. But there isn’t enough concern with tire pressure loss (both molecules will effuse) that I’m willing to pay for nitrogen. There’s no need for the average consumer to fill their tires with nitrogen since they need only check (or have checked) their tire pressure regularly. I don’t think I’ve ever had an oil change that didn’t include this as a matter of course and I regularly check my own.

There is, of course, the argument you’ve posited that the average consumer doesn’t check their tire pressure and that at least one tire is under-inflated, etc.

But this argument is utter bollocks when examined closely. The under-inflated tire is rarely due to diffusion of air molecules through the side-wall and is nearly always because of some other issue such as a puncture, fissure, poor seal, or faulty valve stem or valve. This is logically the case since if conditions are equal for each tire, an anomaly must have an alternative explanation other than diffusion or gas molecules permeating the sidewalls. This is an important point since each of these issues create points of egress that are large enough for both molecules. At this point, Graham’s Law takes over and the nitrogen will diffuse at a faster rate. This is not a matter of debate, it’s physics. QED.

Additionally, if we were to concede that pressure loss were problematic due to the owner not participating actively in preventive maintenance, then we also have to remember that nitrogen also diffuses and looses pressure. Therefore, what’s needed isn’t to charge $60.00 per tire to replace air with nitrogen but to educate the public on the importance of preventive maintenance checks and services. If the owner just gets their oil changed at a reputable service station, their tires will be checked and pressurized if necessary.

The “average consumer is ignorant” argument is like saying the average person doesn’t floss or brush twice daily so they should visit their dentist once a month for a professional cleaning.

Anyway, thanks for dropping by.

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21 Responses

  1. Where did you get your estimated cost of $60.00 per tire? “Therefore, what’s needed isn’t to charge $60.00 per tire to replace air with nitrogen ”

    The average cost is $5.00 per tire and to me it’s worth it. I have been involved in the racing industry for years and see the difference in heat build up in air filled versus nitrogen filled tires.

  2. Here is a study for you, it appears you don’t look to deeply for things since it took me all of about 1 min to find this on google.

    http://www.retread.org/PDF/M-Mech%5B1%5D.pdf

    • This is a website for TRUCK tires, which is not the issue being discussed. Regardless it seems like the article has been removed. The little skeptic inside me smells shenanigans.

  3. Where did you get your estimated cost of $60.00 per tire? “Therefore, what’s needed isn’t to charge $60.00 per tire to replace air with nitrogen ”

    The figure was given to me directly by the Ford dealer that was attempting to sell it to me. It was the initial cost to replace the normal compressed air in each tire with pure N2. You are, however, correct that periodic maintenance to “top off” the tire was less. But the caveat was that should I find that I have a need to fill my tire (perhaps following a puncture on the side of the road where I plug the tire myself then top off with my portable compressor), I need to pay the $60.00 to have the tire emptied and recompressed with N2.

    The average cost is $5.00 per tire and to me it’s worth it. I have been involved in the racing industry for years and see the difference in heat build up in air filled versus nitrogen filled tires.

    Cool. I’m not in the “racing industry” nor are the majority of consumers.

    Here is a study for you, it appears you don’t look to deeply for things since it took me all of about 1 min to find this on google.

    Actually, I could easily make the same ad hominem accusation of you, punctuating it with the fact that you don’t read well. In this or another post I made on the topic, I readily conceded that: 1) N2 does permeate normal tire walls more slowly than normal compressed air; 2) there is a benefit to both the “racing industry” and the long-haul trucking industry.

    My chief contentions are, which you have not successfully argued against:

    1) While N2 permeates rubber at a slower rate than normal compressed air, it isn’t that much slower.

    2) The situations that cause increased leakage such as tire defects, poorly sealed valves and stems, punctures (where the foreign object remains in the tire), etc. will necessarily cause N2 to leak faster than O2. This is due to Graham’s Law and is a matter of physics. In terms someone in the “racing industry” might understand, the hole is large enough for both molecules to fit, therefore the lighter molecule is faster in leaving. The diatomic molecule of nitrogen is lighter than its diatomic cousin made of oxygen.

    3) The average consumer doesn’t need to pay for the additional cost of N2 when a good service station that does an oil change every 3000 miles or 4 months will also check their tires. If this isn’t automatically done, one need only ask. I have yet to see a Jiffy Lube or Walmart charge for air in tires.

    3.1) The average tire holds its pressure longer than 4 months baring any tire deficiency (see point #2) according to the Consumer Reports study (which is published and cited in the post above).

    4) The argument that the tire degenerates or deteriorates at a quicker rate because of O2 and moisture in the compressed air is neither cogent nor sound since consumer tires get replaced due to wear on the tread, which occurs at a rate that far out paces internal wear. The premise to that argument includes the assumption that, for the average consumer the reverse is true.

    I feel I must also point out that that the “study” you so graciously link to above is, in fact, not a study at all but a tire or nitrogen industry slide show that claims to present data from a study. The actual citation for the study the slideshow author claims exists is no where to be found in the pdf file, though I may have overlooked it. If you should know of the peer-reviewed publication that published the actual study, feel free to link it or cite it here. Publication, date and name of the study would allow me to locate it, but you can add the page number(s), volume and issue if you know them.

    But I can’t see how it would make a bit of difference since, even if we were to accept at face value the information the company (which seeks to make a profit from N2) presented, its being presented in the context of long-haul truck tires.

    Finally, I also conceded in at least one of the posts I made that, all things being equal, pure nitrogen would be a better choice for tire inflation than normal compressed air. But all things aren’t equal: the average consumer uses his car to get to work whereas race-car drivers and OTR truckers are at work. The cost/benefit analysis doesn’t favor the average consumer. As long as there is a fee to compress a tire with nitrogen that exceeds $0.50 / tire, filling a tire with nitrogen is a scam.

    The nitrogen tire industry, when sold to the average consumer is a scam.

  4. The ambient air you put in your tire is ~70% nitrogen.
    Smaller oxygen molecules leak out of the tire faster.
    Wouldn’t eventually, as you are maintaining air pressure, the ratio of nitrogen in your tire increase naturally because the oxygen is leaking out while the nitrogen is being retained in the tire? So if you took a 5 year old tire that has been properly maintained and measured the air content of the tire, shouldn’t the amount of nitrogen in the tire be higher than in the ambient air?

  5. I am not in the racing industry, but using Nitrogen I am 22,000 miles over the estimated life of my tires with about 1/4 of the useable tread left. I also have picked up about 3 miles per gallon on the interstate. The car is a 97 Camry with a 22r 4-cylinder. Of course, the gas mileage did not improve in town because you do not loose gas mileage while sitting still from under inflated tires. The Nitrogen in my Camry was free from Costco with a new tire purchase; maintenance is free also. However, I did have my tires in my truck evacuated and refilled with Nitrogen and got similar results – about 4 mpg on the highway and after about 10,000 miles seem to be wearing less. It cost 15.99 to do all 5 tires – including the spare, and maintenance is free also. I have not checked the pressure of my tires in either vehicle yet, but I do get the same mileage in hot or cold weather.

    Not everyone checks their tires every 3,000 miles – or ever for that matter. Highway safety lists it as 60% of people as a matter of fact. Nitrogen works, sorry to disagree, but it works for any vehicle, any year, and under any conditions – it has been tested over and over. You should try it out – but do not ever buy anything from a dealer. Find a tire shop that does it, they usually put out coupons for decent prices.

  6. Actually, I am curious to know how a Nitrogen molecule (N2) is larger than a molecule of Oxygen (O2). I have heard this arguement many times. Nitrogen has a molecular weight of 28.01grams/mole and Oxygen (O2) has a molecular weight of ~32.0 grams/mole. This is fairly common knowledge. In addition, the occupancy of electrons in oxygen’s orbitals are slightly greater. So, to say that it is the oxygen permeating the tire faster than nitrogen would be a misnomer. If anything, the water vapor would be the faster diffusing molecule. But, I have yet to see a tire weeping water, because under the average 34psi the present water vapor would quickly condense. The only argument that could be made is that due to oxygen’s slightly higher molecular weight, the rotational mass of the tire would be greater causing the effort of acceleration to combust slightly more fuel. Conversely, “decceleration” would wear brakes at a faster rate. However, since approx. 78% of the Earth’s atmosphere is Nitrogen, the +/- 21% oxygen would have very little effect on the roational mass of the tires. Finally, most garages that I have seen advertising this scam, only offer “high purity” nitrogen. giving no data as to the actual percentage of nitrogen, high purity could relate to anything from 50% to 100%.

    To make a claim stating that the tires “seemed to be wearing less after about 10,000 miles” is hardly a qualifying statement on filling with nitrogen.

    Let me preface this next statement by saying that it refers primarily to passenger cars. This is not a brand new revalation by scientists toiling away in a laboratory for years on end. This is an old topic, the tire/auto/etc. industry brings this up about every 15 years or so. It’s all the rage until people realize its easier and cheaper to just inflate their tires with regular old 78% pure nitrogen. It’s just snake oil.

    • Great post! Are you a physicist? Do you have knowledge in vehicle dynamics/physics?

      • ‘tactical’ driver? I like the wannabe factor, there!

        Are you a dealership service department manager, or tire shop owner?

  7. I think it comes down to cost – is it worth the cost? At 60 bucks a tire i think its a no-brainer that its a scam. However at 5 bucks or so a tire, why not give it a try? My mechanic will do it for 30 bucks for all 4 tires so I gave it a try. If it saves me a couple of miles per gallon then its worth it.

  8. I have worked in the auto industry for near the last decade. In recent years auto makers are installing tire pressure indicator sensors that cary a 5lb threshold to turn on an indicator lamp. Every fall and every spring hundreds of customers come through the door complaining about the tire pressure light. We sell nitrogen as a one time expense of $40.00 with a life time refill. The customers that utilize nitrogen that come in with tire pressure lights on are far and few between. So my suggestion to those out there that share thier advise with no personal experiance is to get some and then share your advise.

    • Anecdotal evidence that something works is just as valuable as anecdotes that something does not work: that is, worthless.

      If you had sold them all a $2 tire guage, I’m betting you would have seen the same results. (but with $38 less revenue to your shop)

  9. OK, I thought it was “snake oil” when I first heard about it. On my own car with compressed air in the tires I got about 11K miles out of the first tow set. They were Yokahama Advans and the car is a Mitsubishi Evolution. Then, on a whim, I tried nitrogen on the (3rd) new set of Yokahamas. What I found was that they went 17K miles and kept the pressures much better. Gas mileage may have improved – tough to say. It look to me like it made a difference.

    I read the Consumer Reports study and the only thing I find wrong about it is that all they did is fill the tires and set them in storage. They should have used the tires. The normal heat cycling is what makes the difference.

    Anyway, I think the stuff makes a difference. And it was only $40 for all four tires with free top off’s.

  10. I have a 9 month old Lexus GS350 that came new with nitrogen filled tires (did not cost me extra). I live in Florida with mild winters. I drove up to Nashville for vacation. When the temperature hit 27, my low tire pressure warning came on. It bounced on/off (mainly on) for several days. So I bought a tire pressure gauge. All 4 tires were between 28-30 PSI (normal is 33). I called the two local Lexus dealers. One does not use nitrogen. The other wanted $50 to top off my 4 tires !!! So, I went to the local gas station and paid $1.50 to use their air pump. Maybe if they come out with do-it-yourself kits (like the freon kits) it will be affordable, but even with a $50,000 car I refuse to pay $50 to refill 5 pounds of nitrogen in each of 4 tires !!!!

    • Sounds like the tire pressure gauge was a better investment than the top-up charge. Chances are, you would have had to let that pressure back out of your tires when you got back to Florida anyway. Once the temperature came back up, the gas would want to expand and your tires would then be over-pressured.

      I think you already found the Do-It-Yourself kit. It was at the gas station.

  11. The reason people get better mileage with nitrogen is because they are paying attention to their mileage. Those same people who use nitrogen check their tires regularly and keep them properly pressurized. Just check your tires regularly, drive carefully and you will get the “nitrogen” benefits with no cost involved.

  12. What a testament to PT Barnum! All these nitrogen believers (for consumer vehicles driven under normal consumer conditions) sound like the same people who are routinely “cured” by the placebos given in drug clinical trials. If youthink you’re going to get better mileage (or if you were told you would), then you will paymore attention, and you most likely will get better mileage. Same for keeping tire pressure up to snuff. Get a grip, people!

  13. I think the arguments for using nitrogen are the best for proving it to be a scam. If the oxygen leaks out more quickly than nitrogen, then each time we air up a low tire we increase the percentage of nitrogen. After a half dozen fills, the gas in the tire should be 99+% nitrogen and we got there without the expense of the initial nitrogen fill.

    Moisture in air can cause problems but since I live in Texas and have aluminum wheels, it isn’t much of a worry.

  14. There is one killer argument you all forgot: You get green vent caps!

    Why use Nitrogen? Why not use a gas with larger molecules? That would leak even slower. Except when you have a leak.
    If you don’t have a leak, air pressure stays more than long enough.

    In race cars, it probably is easier and cheaper to have a nitrogen tank than to dry the compressed air properly, and water is about all that is an issue there. On the other hand, if it makes you feel better, why not. Some people have a little statue on the dashboard and swear that it helps.

  15. All I can say is this:
    http://TheGearHeadSkeptic.wordpress.com/2010/07/24/nitrogen-filled-tires/

    1) Yes, nitrogen gas does indeed expand and contract with temperature changes, sorry. Fail.

    2) Water vapour contamination in the air will cause more pressure change and rusty rims than oxygen in the air. Use an in-line dryer on your air compressor if you live in humid areas. Fail.

    3) Nitrogen “filled” tires don’t contain pure nitrogen. There is always some amount of oxygen and other gasses in there. This cannot be overcome in a normal tire shop (unless they have a special room filled with 100% pure nitrogen, at greater than ambient pressure, and give their tire tech SCUBA-like breathing gear to wear while he mounts and balances your tires, which they don’t). Fail.

    4) If oxygen escapes through the wall of a tire faster than nitrogen, doesn’t that leave a high-nitrogen gas mix inside the tire anyway? Top up with compressed air a few times and you’ve got a nitrogen rich tire at no cost. Fail.

    5) Yes, NASA and NASCAR use nitrogen in tires, but for very different reasons than the average motorist would ever need. Your Prius isn’t going to climb from sea level to 35,000 feet in two minutes any time soon, and your wheels are not made of magnesium (that tends to explosively combine with O2 under certain conditions). Fail.

    Of course, I could be mistaken and am open to learning something new. If you can change my mind with facts and evidence, I’m all ears. Anecdotes need not apply.

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