A couple things;
- do not exceed max rated pressure because that is maximum rated. Tires can be damaged by too much pressure
- N2 is a smaller molecule than O2. Therefore it will seep out of the tire at a higher rate than O2.
- carpet samples because they are soft versus hard concrete. On carpet, the bottom of the toe is not as flat as when on concrete. I always got deluxe thick samples, cut them in half and stacked them two high four extra cushion and reduced chance of flat spotting a Summer or soft compound tire.

 

Have any of you actually experienced flat spotting after storage before taking the steps suggested within? I would have my C2S sit for weeks on end in the winter in between nice days for drives and never had an issue. Just curious.

 

Yup! Ruined a set of Nitto’s due to sitting on concrete for 62 days. Tried running it out, but after 100 miles I knew they were garbage.

 

Ever fill my tires with the air from migrating wood duck farts as their special N rated release contains larger and more fragrant molecules.

 

You have your info backwards. . .nitrogen molecules are larger, not smaller than compressed air. so the leakage rate is less. Additionally Nitrogen has less expansion as the tire heats up, so the pressure remains more consistent.

 

PV = nRT

The gas doesn't matter.

The reason that, in general terms, nitrogen fill tires exhibit a more consistent pressure over a temperature gradient, is because nitrogen tends to be drier. Since people that run and maintain those systems tend to do a pretty good job, vs the $0.25 pumps at the local Kum & Go.

 

Dang!

Check out the big brain on Van...
Ha ha! Kum &go... good one...

https://cars.usnews.com/cars-trucks/nitrogen-in-tires

ẞ

 

Yes - destroyed two sets of tires (one Bridgestone, one Michelin) on my 993 in South Texas while traveling in the ME for durations over a month. Expensive lesson. Now I do as Lex advises. Also, my experience is that one must be extra careful if you get rapid temp changes like the 80 -> 35 day we had last week. If you don't get the air back in the tires after that level of drop, they will flat spot in a hurry - though you can usually run them out.

cheers!

 

Sorry, what I was taught is the molecular weight of N is 14 versus 16 for O, and 28 for N2 versus 32 for O2. N2 is a smaller molecule, but it's lower molecular weight results in more Brownian motion and faster diffusion rates, in practice.
Service shops I've talked to have been dropping.N2 fill for tires, because it has not proven advantageous in practice.
Here is one empirical comparison -
https://powertank.com/pages/nitrogen-truths-and-myths

 

I have your solution!!!!!!

Seasonal Tire Air

 

I think the Ideal Gas Law above is more applicable to finding a missing element.

For finding a change in pressure owing to a change in temperature Gay-Lussac's law is applicable ( P1/T1 = P2/T2).

Regarding preventing flat spots on tires, it seems the most robust solution is to get the tires off the ground, which on my 991.2 is fairly easy to do. I jack up one side at the rear jack point and place a stand beneath the front jack point and and another stand beneath the point where the lower suspension link joins the cross-beam at the rear. Then repeat for lifting and supporting the other side of the car.

Jason