Max PSI *while* on the road?

[Griswards]

I see all sorts of discussion about PSI and cold/hot temps, etc. etc but here's what I can't find... I'm using RVIBrake's Tire Patrol and my cold pressure was set at 100 (which I might lower towards 90 after I get a good weigh-in, but that's a separate conversation!)

About 4 hours into the drive, RVIBrake alerted me that my right rear interior tire was hitting 120PSI. However, the temp was only 80F on the tire. Everything else was around 112-113.

I slowed down for a bit, it slowly went back down around 116PSI.

What is a PSI that I should be worried about, if temp is low? What does everyone dial their TPMS sensors in for alerting a high PSI?

[clr]

I run H rated tires now on my 5th wheel that are rated for 125 psi cold for maximum carrying capacity. I do not need all of the capacity that a 125 psi tire would give me so I run them at 110 psi. The TSI monitor setup book says to put the low pressure warning at 10 percent below the 110 psi and the high pressure alarm should be set at 20 percent above the 110 psi. So the low pressure alarm should be set at 11 psi less than 110 or 99 psi and the high pressure alarm should be set at 22 psi more or 132 psi.

I have had the low psi alarm go off on a very cold morning when I first start off, but it goes off within a few miles. I have had the high pressure alarm go off on me several times. This will normally happen when it is warm and I have been driving on the Interstate at 65 mph and then take an off ramp and have to sit at a stop light. I tired of this because the alarm would go off at only 133 psi, so I pushed the high pressure alarm up to 136 and it is no longer a problem. I do not see this as a problem for me because a 125 psi cold tire plus the 20 percent would be a high pressure of 150 psi.

[Frameman]

I personally think to much technology is not a good thing! Check your air pressures with a tire gauge .after driving a few miles with a manual tire pressure gauge! Then you will know for sure !

[llr]

as long as you started with the correct cold pressure I would not worry about the high unless there was extreme outside temperature changes during that time. I believe the pressure change is about 2 PSI for 10 degree change.

With one tire being substantially higher that does concern me some, especially with it being an inside tire as the sun wouldn't be hitting the tire and raising it. I would have that tire removed and carefully inspected as you could have a broken belt or another defect that could cause failure on the road.

[houstonstroker]

Per the instructions for my TPMS, I set the high to 120% higher than the cold pressure and 90% for the low. So if my tires are 100PSI cold then the high is 120 and the low is 90.

[5picker]

20% for the high... 10% for the low.

One tire being that much higher than all the rest could be a concern.
Is it near(er) an exhaust pipe?

[mtnjeeper]

On our DS30 the inside rear tires set off our monitor on a regular basis. The others do okay. I'm planning to bump up the high limit for the rear. My TPMS and my tire gauge match on pressure readings.

[DieselDrax]

The only reason I can think to see a higher PSI without seeing a higher temp (temp increase = pressure increase) compared to the other tires is excessive moisture inside the tire. As the tire heats up the moisture changes to water vapor and causes a much higher pressure increase compared to a "dry" tire. This can lead to an over-pressure blow-out if it gets high enough.

That's a big enough pressure difference without a corresponding temperature increase that I would be concerned and would have a tire shop check it out including pulling it off the rim and checking for signs of water.