Charles, Diane and Greg,
Thanks for your replies. Here's a picture of the tag on the inside over of my "Winnebago Motorhome Operations Manual" and see what you get out of it. It appears to call for 28 psi all around with GVWR of 6000 lbs. To me, 28 does seem very low. With 65 lbs of air in the tires, it's a hard ride. Maybe I'll try 45 to 50 psi and see.
Michael