Talk:Cold inflation pressure

This article is WRONG. It does not take into account atmospheric pressure. From physics, the ideal gas law says that PV=nRT where P is absolute pressure and T is absolute temperature (Kelvin). V is the volume and is assumed to be relatively constant. nR is constant. To understand this, assume the tire was filled when it was 300 degrees Kelvin or 80 degrees Fahrenheit. If the temperature varies 10%, i.e. 30 degrees Kelvin (also 30 degrees Celsius) the pressure varies 10%. So if the tire was filled at 80F to 32 psi (or 47 psi absolute when we add atmospheric pressur), the change would be 4.7 psi or .16 psi per degree Celsius or .1 psi per degree Fahrenheit or 1 psi for every 10 Fahrenheit degrees.

This article predicts .6 psi for every 10 Fahrenheit degrees. The actual number is 1 psi for every 10 Fahrenheit degrees.

This is physicist, Stephen Henning, retired from AT&T Bell Labs. I can work up a correct article at a later date. — Preceding unsigned comment added by Rhodyman (talk • contribs) 15:01, 7 December 2015 (UTC)

I completed correcting article using absolute temperature and the ideal gas law. The tables were generated using commonly accepted values for average atmospheric pressure.

Stephen Henning — Preceding unsigned comment added by Rhodyman (talk • contribs) 22:37, 15 December 2015 (UTC)

I saw the recommendation on the page for the table graphic that a wikitable was preferable, so here is the wikitable. Rhodyman (talk) 21:05, 11 February 2016 (UTC)

Ridiculous over- and under- explaining
Oh my god - I came here to learn about "Cold Inflation Pressure" for tires - not a physics lesson. All that crap could be a link to 'laws' - no value here, only confusing. (Apply your vast knowledge and make it usable for normal people.)

I was hoping for something like...

Definition: xxxxxx and then, why that definition is adequate or inadequate and then, when to supplement that definition and the action taken from it.

Then I would want more info on the average case (personal autos)- how did manufacturers come up with this 'standard', how does it represent the average case, how to decide to vary from the average case, and how to 'prove' one was right in varying.

Then would be a time for discussing (lightly, again with links) geometry and pressure and such particular to average case - auto tires - and if links were needed for supporting arguments (laws) then just a link. And then, maybe a bit of discussion on on tire temp rise versus ambient temp rise - for the average case. Such as: If you have to fill a tire, and you KNOW you're starting in the cold mountains and will soon be in the hot desert. Maybe a simple graph would be good here, no fine units, just hotter colder (maybe long trip vs short trip) vs more or less pressure.

71.115.31.3 (talk) 10:10, 17 April 2018 (UTC)


 * This is engineerig!
 * Engineers help people like you to have a better life through development that might bring progress to the humanity and making things easier, saftier and better!
 * So, if you are a dum idiot with that kind of stupid behavior, just go out to a gas station and ask which is the cold pressure to your tires.
 * But if you are clever, than be smart and learn something that can even make you save money using right tire pressure to you vehicle and compensating it to different weather changes. 2804:431:D77F:9FF3:19D4:1D86:F442:448B (talk) 19:02, 11 December 2023 (UTC)