Is Tire Pressure Stamped On Tire Sidewall The Hot or Cold Rating?

Question:

Ive read on many similar posts that running the trailer tires at max pressure that the tire is rated for is what were suppose to do. The tires on my 5th wheel rv are G rated with a max pressure of 110. Using TPMS is see pressures 10 to 15 psi higher than the max rated pressure when towing in 80 to 90 degree weather. So is it safe to say that 120 to 125 psi on a tire rated at 110 is ok? Or should the tire pressure cold be 95 to 100 so that when the tire is heated up reaches max psi of 110.

asked by: Kevin

Expert Reply:

The max PSI rating stamped on the trailer tire is the cold rating. Since your Load Range G tires on your 5th wheel trailer are rated for 110 PSI, that is what you want the cold pressure to be. For example the Provider ST235/80R16 Radial Trailer Tire - Load Range G # PRG80235 has the same load range G rating of as your tires and has a max pressure rating of 110 PSI, so it would get aired up to 110 PSI before the tire warms up.

It is normal for the pressure to increase a bit as the tire warms up, so as long as you keep the cold pressure aired up to the max pressure stamped on the sidewall of the tire, you will be just fine.

I included a video of the # PRG80235 and a link to a helpful FAQ on trailer tires for you to take a look at.

expert reply by: Samuel C