Monday, September 15, 2008

Nitrogen and Shark Cartilage

It’s been one year since Chuck Cohen, director of Palm Tran, Palm Beach County’s bus transit system, announced that he was testing the effectiveness of filling his bus tires with nitrogen instead of air.

At that time, he said the tests would take up to a year, and he promised to share the test results with me and everybody else.

Readers of this blog and my Hometown News column are familiar with two previous articles I wrote on nitrogen in tires: “Don’t pay for nitrogen in tour tires” and “Nitrogen scam foisted on Palm Tran.”

You can read or re-read both of those articles by clicking on my blog, (or go to the archives section on HTN’s Web site).
I also posted the “Consumer Reports” article, “Tires-Nitrogen air loss study,” from Oct. 4, 2007 on (click on nitrogen-filled tires information).

This one-year study is the strongest, most authoritative proof that there is no measurable advantage to using nitrogen instead of regular air in your tires.

I sent Chuck Cohen three e-mails, beginning last March, asking him for any information he might have about the results of his testing. I received no replies until he finally answered my last e-mail this morning, Sept. 12. He wrote, “I will get back to you in the next day or so with a longer response.”

I received the below e-mail from Mr. Cohen, just before the deadline for this column. It’s now clear to me why he did not answer my e-mails but it’s not clear why he did not publicly announce the six-month delay in testing as he did the earlier erroneous date.

“Sorry for any delay in getting back to you, but as you are probably aware, we had several major things going on over the last week or so, including a fare hearing on our proposed fare increase for our paratransit service, that had to take precedence.

“While we did publicly announce that we were going to be testing the use of nitrogen in 2007, the actual testing did not begin until 2008. That was due to a delay in getting the nitrogen units installed in our North County (WPB) facility until January 2008.

“Our fleet conversion then took approximately 30 days and our testing began in February 2008. Our current plans are to complete our testing by the end of January 2009.
“I will insure that you get a copy of the test data when the test is done and our results are written up. Thanks for your continuing interest in this project.”

I responded by asking Mr. Cohen the following four questions:

• When you “publicly announced” that testing would begin in September 2007 and would be completed within a year, why didn't you also publicly announce that testing was being delayed for six months?
• I e-mailed you in March asking you about the testing results while still under the impression, as was the public that the tests were in process. I e-mailed you two weeks ago, asking the same question and a third e-mail one week ago. Why did you not respond to my e-mails until last Friday?
• When will your tests that commenced last February be completed?
• Will you advise the public and me if you delay the testing again?

Remember that this test is being conducted at an approximately $65,000 taxpayer expense and it is being conducted months after the “Consumer Reports” study was already published.
There was another article in “The New York Times” within the last year that came to the same conclusion about nitrogen in tires being worthless. The author, Tim Moran, has asked me to keep him posted on the developments with Palm Tran.

In an e-mail from Tim this morning, he suggested that, in addition to profit, one of the reasons so many car dealers are selling nitrogen is that they believe it does customers’ tires no harm.
I e-mailed him back and said, “What these folks don’t understand is that there is a detrimental effect when you make people believe in a product that doesn’t work. Item No. 1 in your list is that ‘it does no harm.’”

Drivers should really check their air pressure at least monthly, but with the “magic nitrogen” in their tires, they probably won’t feel it’s necessary.

Shark cartilage is “harmless too,” unless you don’t see your doctor regularly for checkups because you believe you can’t catch cancer.

I checked with four different car dealers to see what they are charging for putting nitrogen in tires.

John Pierson Toyota of Stuart charges $50. They used to have an addendum label on all of their cars with a charge of $199 for nitrogen. I guess that was a little more than people were willing to pay.

Schumacher Infiniti and Royal Palm Toyota both charge $39.95 and Maroone Toyota in Fort Lauderdale charges $37.95.

Tire Kingdom is also pushing nitrogen and it appears as if most car dealers in South Florida are selling it, too.

One of the reasons I’m pressing Chuck Cohen, Palm Tran and Palm Beach County government officials for justification of using nitrogen in bus tires is the fact that their using nitrogen adds legitimacy to all of these service departments that are peddling a worthless product to you, the consumer and tax payer.

If Palm Beach County government officials give their tacit endorsement of nitrogen by continuing to use it in their bus tires, you can bet that every seller of nitrogen in Florida will tout this as absolute proof that nitrogen in tires gives better gas mileage and longer tire wear.


  1. Excellent point. My old opinion was "so what...what can it hurt?"

    After reading this, I see how dangerous this "placebo effect" can be.

    Thanks for a good article!

  2. The Other side of the Coin...

    A total of 175 truck tires were tested until they were worn down to the tread wear indicators (TWI). About 125 of these tires wore out without failing at mileages ranging from 125,000 to 225,000. About 50 of the tires failed physically at varying mileages generally on the low side. All the tires had been carefully monitored, measured for tread loss etc., and inspected at 10,000 mile intervals, a lot of them at 2000 to 3000 mile intervals. Tire sizes were mostly 11R24.5 & 11-24.5 with a very few 10R20 and 10-20's. About half of the tires had operated over the eastern part of the United States while the other half had run mostly in the southwestern part of the U.S.

    When the tires were removed from service small samples of tread rubber were taken from the shoulders of the unfailed tires and from the actual failed areas of the destructed tires. These specimens were then subjected to the electron microprobe examination that has been described previously. The examination was specifically directed at determining oxygen and sulfur levels which was best accomplished by using IOKV (10000 electron volts) electron beam And an exposure of 30 seconds.
    Both of the figures tell the same story. When a tire lives to wear out, the oxygen slowly migrates and permeates its way into and through the tire cord body and finally into the under tread and then into the tread itself. It takes a long time for an appreciable amount of oxygen to reach the tread since most of the oxygen gets waylaid along the way by the liner, and then the cord arid cord insulation compound.
    One reason that truck tires can run 250,000 miles with the original tread while passenger tires can only go 50 to 60,000 miles lies in the relative bulk of the 2 different tire bodies. The bulkier the body the longer it takes for the oxygen to work its way into the tread. Unfortunately the bulkier the body the higher is the heat buildup and the faster is the rate of oxidation of the available double bonds. Once the tire body is all oxidized the tire is dead no matter how much tread remains on it. The thinner the tire body the lower the running temperature and the slower the rate of oxidation with a correspondingly longer life.

    Practically all tire engineers throughout this century attribute the gradual loss in tire strength to be the result of "fatigue" when in reality this "fatigue" is nothing more than a slow inexorable oxidation taking place at the available double bonds of the rubber molecules.

    In one experiment involving 54 new 10.00-20 truck tires, 33 were inflated with nitrogen and 21 were inflated with air. These tires were run side by side on the same tractor units until they failed or until they wore to the tread wear indicators. In this case the 54 new truck tires, nitrogen inflation resulted in 26% more miles being run before tires had to be removed when wear reached the tread wear indicators.
    In the case of the failed tires a smaller percent of nitrogen tires failed physically (30% vs. 57%) and they gave 48% more miles before failing than did the air tires. This 48% improvement is due to the tire bodies lasting longer and not the better wearing properties of the tread which is the situation with the tires that lived to wear out.
    The experiments involving 54 new and 44 used tires running some 7,345,497 tire miles in drive axle service, when viewed in light of the election microprobe experimental findings presented earlier, depict a clear cut picture of what nitrogen inflation can do for the transportation industry - cost wise as well as safety wise.
    Nitrogen is dry and contains no moisture. Nitrogen is inert so rust cannot form since there is neither oxygen nor moisture present to cause oxidation of the wheel.

    Copyright Lawrence R. Sperberg, Probe Forensic and Testing Laboratory, El Paso, Texas. All rights reserved.

  3. Earl,

    You disgust me. You call out other dealers by name all for your cause. You are absord and a disgrace.

    The real issue at hand is you are telling lies to the readers of this blog. NITROGEN IS BETTER FOR TIRES!!!!!! PERIOD!!!! You can not fight it. Charging gross amount of money for nitrogen is wrong and this is the only part of your argument that is true and makes sense. Since Nitro generated air is 99% nitrogen is has bigger air molecules and does not leak from a tire at a the same rate of speed that regular air does. Since regular air contains about 76% nitrogen, THERE IS A DIFFERENCE. Regular air leaks out of a tire about 1 pound per month, where as Nitro leaks out about 1 pound every 4 to 6 months. SO AGAIN THERE IS A DIFFERENCE. Since people are very poor at checking tire pressure most of the tires on the road today are under inflated. Nitrogen helps with this issue since people wait to check their tires at service check ups. This does reduce tire wear. IT DOES!!!! Nitrogen also contains almost no moisture so the chances of moisture induced rust build up on steel wheels and in the steel belt does no longer exist. This helps in the prolonging of deteiration of the tire. Again this helps.

    Nitrogen filled tires is a benefit to customers that do not check tires on a monthly basis. Nitrogen filled tires help prolong the life, although minor, of the tire tread. There is a lot of benefit to Nitrogen filled tires over regular air. The concern is the price that dealers and shops charge for this service.

    I suggest to all the readers of this blog to do their own investigation on Nitrogen and if you see a benefit find the best price for this service. Do not continue to allow this man to lie to you because he does not know. Earl Stewart is not the end all end all on vehicle service and what is right or wrong for you. He is however a liar and a cheat and only to steer you to his dealership to blindly steal from you as a consumer.

  4. You are wrong, wrong, wrong, wrong, wrong. Nitrogen air in tires is better than regular air due to the simple fact the nitrogen has bigger molecules that are harder to leak out. It will take longer for nitrogen to leak out of a tire than regular air even though regular air is 3/4 nitrogen. There is still enough oxygen in air that will leak from a tire over time. Now price gouging for nitrogen or not properly representing the nitrogen is wrong and customer should be aware of that, but nitrogen in tires in South Florida is 26% better than air. A tire filled with air is normal to leak up to 3psi per month where as a tire filled with nitrogen is normal to leak 1 psi every 3 to 6 months.

    There have been numerous tests involving nitrogen. Some good and some not so good. Most all of the government tests have been tested on tires not on vehicles proving a false test of normal tire usuage. Then there have been tests that have proven a tire filled with nitrogen maintains a constant tire pressure 50% longer than a tire filled with air. Nitrogen is also a dry air and contains no moisture where air contains moisture that can corrode metals in the tire and the rim.

    Your claim that nitrogen is not good for a customer and or a tire is wrong. You claim that a customer should not be gouged for putting nitrogen in their tire is correct.

  5. 85% of the population doesnt know how to correctly check tire pressure. The AVERAGE car or light truck on the road in North America is underinflated by 11%, reducing fuel efficiency by 3-4% and tire life by 15-18%. Any technology that increases pressure retention is an improvement for the average driver.

    I find it a bit odd that such an authority on nitrogen tire inflation would reference the consumer reports study. After all, there are numerous other studies in the public domain that show significant improvements. Consumer reports took old tires, that had been used multiple times previously, and filled them with compressed air and nitrogen. And let them sit for a year. There is no guarantee that the tires were in the same condition, and if you look at the data, they werent. After all, 3-4 tires showed nitrogen leaking out faster than air, which is completely impossible without a major leak (valve stem, rim, etc.). I have to question the agenda of anybody who references this study as fact when there is numerous other information available in the public domain.

  6. Nitrogen is bettah. Air is bettah, Noooo Nitrogen is bettah. Nooooo air is bettah.

    Nitrofill = Snake oil.

    Miniscule amounts of degradation at microscopic levels! Give me a break! Does it provide a value to the vehicle owner? No way. No how. No Nitrogen!

  7. “Other side of the Coin” versus “Nitrogen and Shark Cartilage”.

    Guys… Most people don’t get it: Earl Stewart must find something different to feed his predatory campaign against other dealers to emphasize his hypothetical role of customers advocate. He could care less if Nitrogen is or is not good. All he wants is a reason to set his dealership beyond suspicion in order to get his audience in the door to sell cars with more profit.

    He sniffs anything that could produce a “reasonable doubt” and capitalize on it. Look his post: “John Pierson Toyota of Stuart charges $50. They used to have an addendum label on all of their cars with a charge of $199 for nitrogen. I guess that was a little more than people were willing to pay.
    Schumacher Infiniti and Royal Palm Toyota both charge $39.95 and Maroone Toyota in Fort Lauderdale charges $37.95”.

    All he is wants is a reason to list the nearby competitors as “Bad Guys in The Block”, and by elimination automatically setting his dealer as the only “honest Toyota Dealer” in town. He is so smart that the analogy he used “Shark Cartilage” implies the punch line “Other Dealers…Sharks”. He is the Phantom of The Opera!

    His intention is obvious. Earl Stewart Toyota is totally incapable of selling the product they represent by showing the customers what Toyota is all about. The Toyota process of doing things, the value of Toyota, The unmatched quality…

    I’ve been repeating myself he should be selling bananas not TOYOTAS.

  8. Yeah! Don't you guys see? Guys?Only Mr. Anonymous gets it. Nobody else understands what Evil Earl is really up to. Everyone but Mr. Anonymous are morons, especially the THOUSANDS of Earl Stewart customers. This mentally inept horde was stupid enough to be suckered in to Earl's dealership with the promise of being treated nicely and fairly. The zombified masses staggered in like un-dead lemmings to do something really dumb like...not pay a dealer fee. Poor things.

    You know what makes us all so dumb? It's that we aren't recoiling in horror like Mr. Anonymous to the notion that Earl Stewart wants to sell lots and lots of Toyotas and make a bunch of money. How evil! And we can't see it? WE ARE DUMB!! AAAAHHH!!!

    Well I for one am grateful that there is a lone, vigilant crusader to protect the intellectually challenged masses who lack the ability to see Earl's top secret and evil plan to sell thousands of Toyotas. Thank you, Mr. Anonymous. Thank you.

  9. Dear anonymous on "Truck Tire Tests",

    Thanks for your very interesting and informative response.

    Assuming your information is accurate, as you say truck tires are much thicker which causes the oxygen molecule migration to remain in the tire fabric interacting with the Sulpher molecules. This is what you say leads to Nitrogen filled tires wearing out and failing faster than air filled.

    I see nothing in your test about fuel economy or tire inflation.

    The hype about Nitrogen in tires these days has to do with $4.00 per gallon gasoline and the false claim that Nitrogen will give you better gas mileage because the tires retain their inflation longer.

    Unfortunately, there is an element of truth in tires being inflated with pure Nitrogen losing their inflation slower than air filled. This difference is minute and negligible for all practical purposes. The Consumer Reports test found that tires lost less than 1.5 pounds after ONE YEAR if they were inflated with Nitrogen. Considering that one should test their tire inflation at least one a month, that small difference makes no difference in fuel economy.

    In fact, the claim can acutally cause a drive not to check her tires' inflation as often as she should.

  10. Dear anonymous [Who says "you disgust me"],

    "A little knowledge is a dangerous thing". You have heard that Nitrogen molecules are bigger than Oxygen. You have heard that air contains 76% Nitrogen [It's actually 78%].

    You're claim that air leaks out 4-7 times faster than Nitrogen is totally disproved by the Consumer Reports test and numerous others. You can read the Consumer Reports test by clicking on

    Your claim is not only bogus but it's dangerous for those who believe you. If a driver only checks his tire inflation every 4-6 months, he will not only get worse fuel mileage but wear his tires out twice as fast. It's also very dangerous to drive on underinflated tires.

    You're a fool if you think I would lie about this and not use Nitrogen in my rental fleet cars and inflate all of my customers' tires with Nitrogen if I believed Nitrogen worked. I give all of my Toyota customers free tires for as long as they own their car [must do all factory recommended maintenance with me. How foolish would I be not inflate them with Nitrogen and save myself a fortune! I spend over $50,000 per month buying tires for my customers.

    You're deluding yourself into believing this Nitrogen myth so you won't feel guilty about selling your customers a worthless product and charging them $40 to $50 for it.

  11. Attention: All you "Nitrogen Fans"

    Rather than waste my breath debating each of you and your illusory idea that paying somebody $40 to fill your tires with Nitrogen is a good thing, I've posted the Consumer Reports Nitrogen vs. air test below.

    Consumer Reports is the leading consumer testing authority on the Planet. They accept no advertising and are a non profit company. Most of the tests that Nitrogen Nuts are referring to in their postings are from companies selling Nitrogen generators or that, in some other way, have a "dog in the Nitrogen show".

    October 04, 2007
    Tires - Nitrogen air loss study
    Filling tires with nitrogen rather than air is becoming a common practice in the replacement tire market. This service offers tire dealers another avenue for making money while also promoting safety. The claimed safety benefits often include the potential for reducing air loss compared to an air-filled tire. Maintaining proper inflation can help prevent tire overheating; promote optimum tread life; and reduce rubber aging and wheel corrosion. The use of nitrogen in large truck fleets and the commercial tire industry are well documented and support these claims.
    The National Highway Traffic Safety Administration (NHTSA) has seen reduced aging of tires filled with nitrogen. Though the data does support that passenger car tires could benefit by all the claims made for nitrogen, tire manufacturers say that they already design tires to perform well with air inflation. And while nitrogen will do no harm, manufacturers say that they don't see the need to use nitrogen, which generally adds $5 or more per tire charge.

    Consumer Reports wanted to find out if nitrogen is worth the price, so we purchased a Nitrogen Inflation System and checked out how well the inflation held up over a one year period. We evaluated pairs of 31 tire models of H- and V-speed rated, all-season tires used in our tread wear test from 2006. We filled one tire per model with air and the other with nitrogen. The test was quite simple: fill and set the inflation pressure at room temperature to 30 psi (pounds per square inch); set the tire outdoors for one year; and then recheck the inflation pressure at room temperature after a one year period.

    The tires were filled and deflated three times with nitrogen to purge the air out of the tire cavity. We also used an oxygen analyzer to be sure we had 95-percent nitrogen purity in the tire--the claimed purity limit of our nitrogen system, which generates nitrogen gas from ambient air.

    The test started on September 20, 2006 and the final measurements were taken on September 20, 2007. The results show nitrogen does reduce pressure loss over time, but the reduction is only a 1.3 psi difference from air-filled tires. The average loss of air-filled tires was just 3.5 psi from the initial 30 pressure setting. Nitrogen-filled tires lost an average of 2.2 psi from the initial 30 psi setting. More important, all tires lost air pressure regardless of the inflation medium, so consumers should check their tires' air pressure routinely. No evaluation was done to assess the aging claim.

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

  12. earl i used to think u were a joke and a sleazeball for naming and putting down the other dealers, but the more i read your articles the more i like what i read! keep up the good job! and if the other dealers dont like tuff cookies!!! and by the way im not a toyota fan(even though they are great cars, or or an earl stewart customer, just a fan of honest men like earl stewert!!!) keep up the great articles.

  13. Earl,

    You must be a moron.

    They tested Nitrogen in NON-MOUNTED tires, under NO LOAD or ROAD USE!

    What the hell kind of test it that?

    Hey Consumer Reports (or Earl Stewart).......I have a great test for you.
    Let's test the effectiveness of Motor Oil in NON-WORKING engines!
    We can fill motors with different oils, sit them in a warehouse for one year without turning them on, and see how each one performs....

    The Nitrogen test was inherently flawed.

    I hope when the PalmTran testing is released with positive results you can accept them, rather than find a new way to reject them.

    But....knowing you, I'm sure you will invent something wrong with their test results.

  14. Thanks for your posting,

    This "moron" has a degree in Physics, a Batchelor of Science from U of F and an Master of Science from Purdue.

    What are YOUR qualifications with respect to measuring the speed of migration of nitrogen and oxygen molecules through tire fabric with the variables being time and pressure?

    You also ridicule Consumer Reports, universally accepted to be the top independent consumer testing laboratory in the USA.

    Who are the readers of this blog more likely to believe?

    You obviously have a "dog in this race" and my guess is that you sell nitrogen to unsuspecting motorists.

  15. I hope you are doing well with your "Batchelor" of Science degrees!


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