I am also of the opinion that there is little or no benefit from using pure nitrogen in tires, but the main reasons for doing so are mitigation of air loss through the carcass of the tire and to limit corrosion inside the tire/wheel assembly.
Tires filled with pure nitrogen lose pressure at a slower rate than tires filled with “air.” The fact that this difference is less than 2lbs/year to me means there is little or no benefit, but there is a difference.
Corrosion inside the tire/wheel is also limited by the use of pure nitrogen. No one here seems to have mentioned that since 2007 model year every tire/wheel has a pressure monitor mounted inside it–an electronic device not too fond of excessive moisture.
Bottom line it’s a profit enhancer.
Nitrogen may be of a little benefit to the NASCAR guys at 180 MPH where a 1/2 or 1 pound here and there can make a little difference in handling on a car that is essentially floating but I don’t see the daily commuter car gaining anything from it.
To back up what “same” had to say, from I what I was able to find, nitrogen may possess some benefits over"air" that has been scrubbed of moisture, but even for race cars, the results may be small, still. But having similar properties of an inert gas, it is better to have around in a pit where fire danger is ever present.
Unless they draw a vacuum before they fill with nitrogen much, most(?) of the air in the tyre when they get done using nitrogen is going to be the air that was there before they began filling it. Since I don’t see how they can draw a vacuum on a mounted tyre (I will bet the seal will be broken long before the tyre is refilled with nitrogen) .
The only two good things about this one, is that often it is provided for free and it should do no harm, other than possible direct or indirect cost.
@dagosa - I’m surprised that Pop. Mech. article used the work ‘compelling’ to describe reasons to use N2, that’s just plain wrong, as is their statement that N2 is more stable with temperature. But I see where you got your info.
Let’s say O2 quickly migrates out of a tire (it doesn’t, but let’s say it does). Your 30 psi tire now reads 24 psi, so you fill it back up. Now you have 96 % nitrogen in your tire! So even if the myth was true, you’d quickly get to about 100% nitrogen after a few tire fills.
texases… hear what you are saying, but the word “compelling” is relative to whom ? Your scenario is a little misleading when you start with the phrase “Quickly migrates”, and your entire point deteriorates for me on your own admitted false supposition. There is NO need to read further then (it doesn’t but let’s say it does).
I would argue that because both 02 and nitrogen migrate slowly out of a tire slowly, and I will assume that a reasonable authority like Pop. Mech. has consulting engineers who are fairly believable…that nitrogen is slower and for some, with a along term car storage project, it may be “compelling” to fill the tires with nitrogen. It may be compelling to those taking curves during a race at near 200 mph too…
So, it certainly is compelling to some IMO, if only the same crowd who feels that the 3000 mile oil changes is normal. Neither of us can find any compelling reason to use it for ourselves but compulsions are relative and I find no reason to doubt the use of the term by PM.
For a long time I’ve been using one of those independent, local shops. Their central specialty is alignments/suspension/tires, but I found that I can trust them with most anything. A pretty good range of techs there.
But I guess they were too good…because they were always way too busy…and backed up from lack of bays. You often couldn’t park in their lot (though it was sort of small).
So then they expanded…major renovation…added a bunch of bays…expanded the parking lot. It got harder to talk to anyone who actually did any work on your car. They also specialized so that I might bring my car in for several different things and find out it ended up being done by several different people. I.e. no ONE was looking at my car or could talk to me about my car.
Things started to go downhill…then they introduced their new “Nitrofill” service. I decided it was time to find a new shop. They used to be car guys who worked on cars. Now they’re just a business. I suppose I can’t blame them since they must now have massive loans to pay off from the renovations. But that doesn’t change the fact that I’ve stopped seeing them as a place that helps me take care of my cars.
Maybe the reason for rust in motorcycle rims is because moisture migrates around the spoke nipples; being helped along by centrifugal force as the wheel spins.
I’m in agreement with Mr. Meehan about how they would go about removing all air from a wheel assembly before adding nitrogen. When the bead pops into place there will be little nitrogen in there because the nitrogen bump would just push the bead over the hump so to speak.
The only way of keeping it pure would be to inflate the tire until the bead seals, pull a vacuum a la A/C evacuation while hoping the bead stays in place, and then refill with nitrogen.
@CapriRacer - I’m wondering if Dalton’s Law might be the source of nitrogen’s very limited value. By starting off with (nearly) 100% N2, there’s going to be some net O2 migration into the tire, offsetting some of the N2 migration out of the tire, helping to keep the pressure a little higher than an air-filled tire. Too bad Consumer Reports didn’t test the starting and ending compositions for their year-long test.
Actually, I believe it’s just an extrapolation from the racing world to the world of daily drivers without an understanding of why nitrogen is used in race tires. It’s used in racing, therefore it must be better in road use…and if everybody thinks that we can sell it and make money!
@dagosa. Thanks for the link to the 1957 Plymouth Fury. These pictures of the1957 Plymouth brought back memories. However, I still prefer the clean look of the 1957 Studebaker Scotsman. However, when the Scotsman returns, nitrogen in the tires won’t be an option.
