Tires always lose air in storage is this normal?

Mine always lose about five pounds

Jack L

Some good responses to this. I will say the tt is usually stored for 3 or 4 weeks and I always pick it up in the evening when I would guess the temp is 60-70 degrees. I will have to try measuring the psi at different times of the day. Also I agree that the nitrogen fill is truly the latest gimmick in the industry, the majority of the atmosphere is already nitrogen so I cannot see how this would make a difference.

We have a TPMS and the vast majority of the time I just plug it in and the tires are all perfect. No lost air. This past summer we did have one tire that would lose about 6 pounds per month. We took it into the tire shop to have the tire resealed to the rim. Happy TPMS, happy me.

The vast majority of the leakage is around the bead. The point of leakage is so big that it makes no difference as to whether your using pure nitrogen or 80%. Both will leak just as much because of the size of the leak.
The leaking through the tire story is marketing hype used by tire dealers to up-charge for Nitrogen. It's just marketing and they are trained to sell this way by the supplier.

Also nitrogen is not a lot bigger than 02. It is infinitesimally larger (75PM vs 72PM) which for the subject at hand is irrelevant.
It's only smaller because it's basically tighter because of charge.

I would not recommend tubes in a tubeless tire.

You may find it will cause more problems than it will solve and possibly void the tire warranty.

As for pressure loss temperature is a big factor. If temperature is the same before and after storage things do not add up. If it were only one tire I would be looking for the leak but you indicate all the tires are involved. As such I doubt there is a leak problem.

ScottG wrote:

Nitrogen will not make any difference because most of the loss is where the tire seals to the rim and that space is relatively large.

Besides this, normal plain air is mostly nitrogen anyhow—roughly 80% by volume. The rest is mostly oxygen, with only a very small portion of carbon dioxide and other gasses.

Oxygen molecules are very slightly smaller than nitrogen molecules, and so do permeate through rubber slightly more quickly, but diffusion of the gasses though the rubber of the tire is slow enough that it's senseless to concern oneself with the difference. It's still necessary to check tire pressure and adjust it as needed on a regular basis regardless.

I was going to suggest that carbon dioxide should be even better than nitrogen, since it has larger molecules, but it turns out that (while the molecules are larger) the chemistry of gasses permeating solids gets rather more complicated and for various reasons carbon dioxide diffuses through rubber fairly rapidly—much more quickly than either nitrogen or oxygen.

ScottG wrote:

kvangil wrote:
My experience has been that it depends on how long it's been sitting in storage. If just a couple weeks, I barely lose anything...Over winter, it may drop about 10psi.

Same here with every vehicles tires I have ever stored.
Nitrogen will not make any difference because most of the loss is where the tire seals to the rim and that space is relatively large.

Air is also lost through the tire rubber. It looks solid, but at the molecular level, it is "open" enough to allow air (80$ Nitrogen, 20% oxygen) to seep through. Note how fast Helium a very small molecule, leaks through a latex ballon vs. "air". With tires there is Not much leakage, but you will loose some through the material. Depending on the tire construction, you could loose a few pounds over the winter to maybe 5psi.

Luckily, Nitrogen, even though it is lower molecular weight than Oxygen, is actually a larger molecule, and leaks at a slower rate than oxygen.

The tubes I use on my off road motorcycle, are very thick but natural rubber. They loose about 1psi/two weeks. When you start at 8-10psi, it's significant.

My experience is that yes, they will lose air. How much they lose depends on the quality of the tire.

kvangil wrote:
My experience has been that it depends on how long it's been sitting in storage. If just a couple weeks, I barely lose anything...Over winter, it may drop about 10psi.

Same here with every vehicles tires I have ever stored.
Nitrogen will not make any difference because most of the loss is where the tire seals to the rim and that space is relatively large.

Had Michelin, Goodyear and bf Goodrich, in the last 10 years. Don't think I had to add more than a few times