I have read from motorbikes that had tmps , wich gave pressure calculated back to 18degrC/65degrF, and they must be using temperature reading of internal sensor.
The calculation then happened in the recever-unit.
But even an internal sensor does not give exact the temperature of the inside tire gascompound, but better then external sensors.

Forgot the name , but the writer behind you describes that he monitored the pressure during trip and changing ambiënt temperature, but did not worry about it and did not change the cold pressure. And that is to opinion the right way, better then maniacaly adjusting it every time.
I wonder if the valves wont wear out faster, from all this.

Best practice would have been to inflate to 105 (your normal cold pressure) prior to leaving Pennsylvania in December. As far as determining correct pressures, what your pressure “gets to” while driving is irrelevant.

Was there a difference in ambient temperature between December and the time that you returned to Pennsylvania? A 30-40F difference would explain why the cold pressure increased from 99 to 105. That’s a perfect example of why pressure should be set when tires are cold.

Someone inflating their tires incorrectly and then not worrying about it does not validate your theory.

It might support your opinion. If that’s what you are seeking, you’ve come to the right place. The internet provides plenty of opportunities to find someone who will agree with you, even if you’re both wrong.

How can you be given so much information that dispels your theories, yet remain so unwilling to accept any of that information?

OK, ambient temperature went from 90 to 60 degrees F this week (yes, in Florida) Stopped and added air to the tires.


Yes, the tires DID read the IDEAL GAS LAW, and followed it. So, I followed it as well. Cold PSI (before driving was too low-- added air).


Have done that every fall/winter since I owned a vehicle (about the same time I had to learn the IDEAL GAS LAW). See, higher education (in the sciences) IS worth something.

Yes, this is the way. :)

MN-traveler wrote in reacton to my long explantion next
I think you are partially correct in that at low ambient temperatures the risk of thermal damage is reduced, but if the tire is underinflated, you still have increased flexure, and thus greatly increased risk of strictly mechanical damage.

Now for ST tires they calculate maxload in the bigger sises for 65mph wich gives to my calculation , if realy maxload on tire and reference-pressure in tire 1.38 x the deflection then a LT tire.
The 1.1 x in my example for 40 degrF against 70 degrF. Is then much less.

OK many ST gave tire-failure, but I still think that was because of overheating, and not the exessive flexing.


Also calculated it for european "for trailer use only" tyres, wich calc in maxl for 140kmph/87mph instead of C- tyre( LT- tire) 160kmph/99mph, and it gave 1.14 x deflection , and those are used often enaugh ( but by these eresponcible Europeans ;) ) for 10 years without failure.

On trucktires in Europe almost always additional service descriptions then fi 154L and 156K.
Calculated that back to 1.06x deflection at 110kmph/68mph against deflection for 120kmph/75mph.
And you cant argue that its a different material or construction, because they write it on same tire.

See picture I made about 2 years ago, above the yellow line.

I agree that there is a limit to the more deflection, but 10% more is not it ( to my conclusion for what it is
worth).

I wonder what all the tire-specialists here, think of my idea to use the higher cold pressure at 100degrF. Example : you determined 80 psi to be right for the axle on a E-load tire.
Then you leave the campground for a long trip in the end of the morning with ambiënt temperature 100 degrF. You filled the 80 psi at 70 degrF ambiënt temperature.
But then you measure 85.4 psi ( as far as you can measure it that acurate, yust for the example).

What must be done.

1 . Leave it at 85.4 psi cold even if that is above " maximum cold pressure " of tire.?

2. Bring back the pressure to 80 psi, becausse 80 psi has to be filled at ambiënt temperature?

My answer you will know, but then again, I dont call myself tire-specialist, only " pigheaded Dutch selfdeclared tyrepressure-specialist "

Check it again the following morning.

There is no other correct answer.

There are, however, incorrect decisions.

But the following morning the trip is already done, so possible damage if wrong decided is already done.

Set it in the morning, then stop thinking about it.

Not even close to accurate. If you're supposed to be at 80 PSI as determined by the actual weighing of the RV and the tire manufacturer's charts (unless these are ST tires which should be inflated to the sidewall pressure when cold) then low pressure is your enemy. A tire that is 20% low is considered to be flat, or 64 PSI in your example.

You may be confused by the pressure molded into the sidewall. That is NOT the maximum pressure the tire can ever see. It is the MINIMUM pressure needed to support the design maximum load weight of the tire.

My motorhome tires do heat up when running and can and do exceed the pressure molded into the sidewall. It's normal and expected and accounted for in the tire design.

Oh, and NEVER let air it of a tire that is not "cold", meaning it has not had direct sun on it and it has not been driven on for hours.

And buy a TPMS.

Ray

Again you seem to have missed the point.:facepalm: Tire pressure is to be set when tires are at the AMBIENT air temperature outside on the start of a trip.:banghead: No adjustment is needed.:dance:


The only exception would be if you are inflating tires in a heated garage and the temperature is much colder. Example it's -20°F (-29°C) outside and the tires on the vehicle are in a warm building at 65°F (18°C). That would be when you would use a "Cold Inflation adjustment" chart that I published on March 12 2021 in my RVTireSafety blog.

You seem to miss my point, and yust keep repeating your argument.

Its not always possible to check the pressure in the morning , and even in europe, 1ce a month checking is adviced and before a long trip.

My example was that exeption, checking before a long trip , but then you measure that 85.4 psi.

Then you argue to bring it back to 80 psi, and I argue to keep it at 85.4 psi, even if that is above referencepressure.

My idea is easyer, you dont have to do anything, and to my conclusions the tires run cooler when driving.

This is hopeless. I’m out.