Comments on: Should I put Nitrogen in my Car Tires?

By: David

David — Wed, 23 Oct 2013 16:40:10 +0000

One of the reasons for using nitrogen in car tires is that it keeps the steel radial belts from rusting. The reddish tinge seen on the sidewalls is not always or only brake dust.

By: tallcharlie

tallcharlie — Wed, 18 Apr 2012 15:34:05 +0000

For normal, long-term use of automobile tires, nitrogen reduces oxidation on the rubber compound on the inside of the tire.

Passenger car tires are inflated to a range of 30 to 50 psi gauge. That translates to about 45 to 65 psi absolute. So if compressed air is used to inflate, the gas inside the tire is three times richer in oxygen than the gas on the outside for the purpose of supporting oxidation.

The rate of oxidation is also proportionate to the square of the operating temperature, IIRC. Normal usage in the summer will see passenger car tires exceed 200 deg. F. This is not surprising when you consider that they can have resting temperatures of 120 to 150 deg. F, depending upon their location. E.g., in direct sunlight.

Oxidation, often referred to as dry rot, is manifested externally in the form of cracks and discoloration in side walls and tread. External deterioration of the rubber is accelerated by the effects of sunlight. Internally, it is accelerated by the relatively oxygen-rich inflation gas when normal compressed air is used.

Obviously, cracks in a tire are not good, as they increase the likelihood of catastrophic failure, i.e., blowouts. They also promote slow leaks.

An argument can be made that by inhibiting oxidation the integrity of the tire is extended and the likelihood of slow leaks leading to an under-inflated condition is reduced thereby increasing mileage potential.

But not by much.

The obvious conclusion is that if you drive enough to wear-out a set of tires every four years or less, nitrogen will not provide much advantage because the tires will be replaced before the oxidation becomes significant. However, if you are like me or Jay Leno, and do not go through tires all that quickly, nitrogen will extend the service life by reducing oxidation.

As to increasing mileage, that’s not very likely.

By the way, a tank of nitrogen and a regulator valve will set you back about $400 and can be purchased at most any welding supply company.

By: N2TYRZ

N2TYRZ — Tue, 17 Apr 2012 04:34:47 +0000

Greg,
Iâ??m not a scientist or have a degree just seeking professional help.
Late model cars with a TPMS system should last longer with the absence of less moisture. An average TPMS indicator in ideal conditions is 6-8 years as I hear, so if you minimize the water introduction into the tire it should have a chance to meet that goal or exceed vs. a moisture laden environment. Would you concur?

By: N2TYRZ

N2TYRZ — Sun, 15 Apr 2012 18:49:45 +0000

Nitrogen if overcharged or not offered free with new set of tires, then Nitrogen inflation could be seen as a scam.
Most tire and car manufacturers have tested and approve the use of nitrogen. Many local tire shops down play the benefits they, first donâ??t want to invest in a machine and want/need to sell tires. Michelin factory in Greenville, SC offers nitrogen inflation station for their employees.
Costco offers nitrogen free when you purchase tires. Do you think they would invest 8-10k per machine at over 400 tire locations if it didnâ??t have some merit? Costco self insures their tires and majority of people donâ??t check psi or rotate as recommended so they have found better performance less failures with nitrogen. Costco sells millions of tires per year.
Jay Leno uses in his entire car collection, Google and watch the video.
Lance Armstrong and other tour De France riders use Nitrogen. A bicycle tire with what little volume it has why would they go to the trouble if not for the benefits.
Nissan GTR is shipped from factory with Nitrogen. Volvo has inflated all their spare tires with nitrogen for years. Most spare tires I have checked are severally underinflated never checked a Volvo yet though.
My opinion and experience using Nitrogen has been positive. Yes regular air would do but I opt for the better inflation media. Nitrogen inflation is obviously not for everybody
Some people use synthetic oil and pay 3-4 times more where regular oil would do a sufficient job but opt to pay extra for better lubrication. Some people pay extra for premium coffee or water too.
I do a part time business a car cruises and have done hundreds of tires with positive feedback on better psi retention, handling improvement etc. Some have gone over 2 years with no psi loss where they would need to top off using air. I charge $20.00 for 4 tires and many times let customers try before they pay. I havenâ??t lost a sale yet due to Nitrogen performance. White wall tires yellow due to the oxygen that seeps through the sidewalls.
My best experience is an independent trucker owner operator. He and his wife are a team that travel 5k every week long haul. Using same brand of tires they average 300 to 330k on driver tires. I put in nitrogen in a new set they got 475k. During that time he did not need to add any nitrogen or rotate tires as he did using air. The tire shop said he could sell the 475k tires to a local trucker and still had some life. I put in my neighbors riding lawnmower where he after winter had to air up tire and during use several times now once a year with nitrogen.
Wal-Mart has tested and converting their fleet to nitrogen. Many other trucking companiesâ??s have done side by side test and have experienced better tire life, less failures and small mpg increase over air.
Nitrogen out performs air whether in an airplane (federally mandated for safety), racecar, military vehicles, motorbike, truck or bicycle tire. Nitrogen inflation will the standard in the future and should be offered free hopefully.

By: Greg Laden

Greg Laden — Wed, 28 Mar 2012 15:53:35 +0000

OK, so water laying around in the tire that got there from basic air being put in the tire, condensed from vapor, will turn into steam in a Formula 1 tire. That would result in a significant increase in pressure of an uncontrolled or at least unpredictable amount.

I imagine that aircraft tires spend most of their time in flight well below freezing (on commercial jet liners) and that air added to those tires now and then would produce a buildup of water. I’m not sure how hot those tires get, but they might get a little warm sometimes:

http://youtu.be/E0kjZ3L9LE8

By: Martin

Martin — Wed, 28 Mar 2012 14:58:44 +0000

Greg: Road use max tire temp is about 75C. Formula One optimal temp is 100C, but they will work up to 160C. Which is why tires are heated before being put on and why the first lap after new tires is slow.

By: Eric

Eric — Wed, 28 Mar 2012 07:52:38 +0000

As far as aircraft go, the brake systems are usually a multiple disc type brake located within the inner diameter of the rim. They get very hot during emergency stops, especially with a heavy aircraft. Most commercial airliners have a warning light that comes on when the brake hits a certain temp (from a quick google search it seems most will throw a warning light at 4-500C)

Back when I was an aircrew member on a large military aircraft a brake locking, aborted takeoff, or other type of heavy weight emergency stop often required an emergency egress. We would have to avoid getting anywhere near the tires in the plane of the axles as the tires would occasionally explode. Ground crews would test the hubs with a “crayon” with a specific melt point to determine when it was safe to tow the aircraft away. I think they tested at 600 and 900 degrees.

It’s very rarely an issue, but I could see the benefit of using N2 as somewhat cheap insurance. I would guess that proximity to the brakes and conduction from brake to wheel could account for significant heat, after all F1 brakes glow yellow hot under hard braking.

By: Brad

Brad — Wed, 28 Mar 2012 05:48:18 +0000

Re the aviation end of it (not an expert, just an interested layman), there are reasons to use nitrogen. Tires on heavy aircraft are inflated to much higher pressures than even heavy trucks (~200 psi?), so if you used air, the partial pressure of oxygen inside the tire would be something like 3 atmospheres. There are foreseeable circumstances such as an aborted takeoff where heat from the brakes would cause the tires to ignite, and three atmospheres of oxygen would be an undesirable accellerant. And tires burning on the inside with possibly no external signs would be a danger to the vehicle, contents and surrounding property. The rims are provided with fuse plugs which will deflate the tire with excessive heat or pressure.

On race cars, if tire pressure is so important, I’d think the lack of water is the key thing, rather than lack of oxygen. And don’t discount superstition and head games either, psychological advantages are still advantages.

By: AnonymousCoward

AnonymousCoward — Wed, 28 Mar 2012 05:27:59 +0000

The issue with air in racing tires is that the water vapor content of air varies from Montreal to Malaysia (and places in between). Using a gas with a known composition makes it easier to predict the tire pressure when they come up to temperature, or so the story goes. I don’t think they actually use pure nitrogen, so it may just be air that’s been dried and filtered.

By: Greg Laden

Greg Laden — Wed, 28 Mar 2012 05:05:49 +0000

So … we’re never going to get incidental condensate to turn into blistering steam that will shoot up the compression in the tires.

Why do race cars and airplanes use Nitrogen then? Are they just being superstitious, or have they bought into the woo, or is there something we’re missing?

Or, do they even really use Nitrogen for realz?