I drive a 32' Itasca Cambria. I keep the tire pressure at 80 psi and the air bladder bags at 35 psi. When we are driving the RV seems to feel every asphalt repair, expansion joints, road damage, etc. ...
And don't assume your tire gauge is accurate. I had a quality tire gauge that read 9 psi too much, meaning I was putting in 9 psi too little. You can read about my tire gauge evaluation HERE.