Tire inflation

Get a front and rear weight at a truck stop or in some states weigh stations will give it to you for free. You need to go up to them and ask the get back in line so it is more involved. Once you know your weight go to the Michelin tire guide and look up the weight. It is ok if you do not have Michelin tires all light truck tires (load range E) have the same standard. So for example my RV has 225/75r16 load range E tires, the front axel weighs 4125 lbs, using the chart below I should inflate to 55 lbs. But I for safety I go round up one group and run 60 Lbs. I do the same for the rear axel I round up to the next group so in back I use 70 lbs. That is my truck and my weights. Your RV will be different. You should not run other people's weights. Your safe running max pressure, but it will make the RV handle funny and may ware the center of the tires early. Getting weighed at a truck stop cost only a few bucks. Then you have no worries.
https://www.michelintruck.com/reference-materials/manuals-bulletins-and-warranties/load-and-inflation-tables/#/