The tire pressure rating is printed on the tire.... WRONG
Go out to your tire and read THE ENTIRE SENTENCE printed there, Not just the last 4 words (Max Pressure yyy PSI) but the entire sentence
Maximum load of xxxx pounds at maximum pressure of yyy psi.
Thus, unless you are running maximum load.. That is NOT the proper pressure.
The pressure written on a tag somewhere inside is likewise all but guaranteed to be wrong (less the rig is empty save for the driver)
The correct pressure is found by weighing the rig and visiting
RV Safety, Merritt Island, Florida or the tire maker's web site.
NOTE: the url above.. Has folks who will come out and weigh you for a fee.