tire pressure and extreme heat
I live in Columbia, SC and will be headed to Florida Keys later this week, pulling my travel trailer. Morning lows have been around 75F and highs around 100F. I've always filled my tires on truck an...
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Did some calculating with use of my made spreadsheet.
Asuming inside tire is totally free of water ( not gas not liquid).
Asuming your AT-pressure to be 80 psi.
Then filled at 65 degr F at 80 psi will become 81.8 psi at 75 degr F and 86.3 at 100 degr F.
The other way around:
Filled at 100 degr F 80 psi.
Becomes at 75 degr F 75.7 psi
and at 65 degr F 74 psi.
So yudge for your selfes if that is worth it.
It would mean that if 80 psi is calculated to be the right presssure for your combination and situation and is meanth for that 65 psi, you need to fill it cold when ambiënt temp is 75 psi at 81.8 say 82 psi and at 100 degr Ambiënt temp at 86.3 psi.
This to get the same savety for the tires.
A tire whith some water in it fluctuates more in pressure .
Have list of partial pressure for 100% humidity at temperature and this shows that the extra rising from 65 to 100 degr F is about 0.67 psi. You then have to add this to the pressure difference for dry air. So the 80 psi at 65 degrF will get 87psi at 100 degr F.
But if you give your AT- pressure , I will do the calculation for that
If higher ambiënt temp the inside tire will get also higher when warm by the heatproduction of bending rubber.
Then the rubber also gets hotter , so gets closer to the temperature where it hardens and so get damaged by next bendings.
The lesser deflection the lesser heat is produced by the tire.
Lesser deflection is what you get when inside tire temp gets higher. So also when the tire inside temp goes up when driving at speed.
So to some extend and mayby totally, the heatening up takes care that the tire produces less heat, so critical spots of tire still wont get to hot that damage begins.
Asuming inside tire is totally free of water ( not gas not liquid).
Asuming your AT-pressure to be 80 psi.
Then filled at 65 degr F at 80 psi will become 81.8 psi at 75 degr F and 86.3 at 100 degr F.
The other way around:
Filled at 100 degr F 80 psi.
Becomes at 75 degr F 75.7 psi
and at 65 degr F 74 psi.
So yudge for your selfes if that is worth it.
It would mean that if 80 psi is calculated to be the right presssure for your combination and situation and is meanth for that 65 psi, you need to fill it cold when ambiënt temp is 75 psi at 81.8 say 82 psi and at 100 degr Ambiënt temp at 86.3 psi.
This to get the same savety for the tires.
A tire whith some water in it fluctuates more in pressure .
Have list of partial pressure for 100% humidity at temperature and this shows that the extra rising from 65 to 100 degr F is about 0.67 psi. You then have to add this to the pressure difference for dry air. So the 80 psi at 65 degrF will get 87psi at 100 degr F.
But if you give your AT- pressure , I will do the calculation for that
If higher ambiënt temp the inside tire will get also higher when warm by the heatproduction of bending rubber.
Then the rubber also gets hotter , so gets closer to the temperature where it hardens and so get damaged by next bendings.
The lesser deflection the lesser heat is produced by the tire.
Lesser deflection is what you get when inside tire temp gets higher. So also when the tire inside temp goes up when driving at speed.
So to some extend and mayby totally, the heatening up takes care that the tire produces less heat, so critical spots of tire still wont get to hot that damage begins.
