[Jeff Teuton]

Our major tire supplier suggest about 10 less than max which is what we do on our fleet of 1500 or so. Mediums and heavies, no light duty. The theory is allow a little more flex on the sidewall on some of the beautiful roads. Low pressure, say 70 in a 120 max tire, is more a problem than too much pressure. The only two motor home conversions are ours. Another note is commercial tires only have a useful life of 3 to 4 years. Most cappers won't cap anything over 3 years old. Not good news for RV's. I changed 10 in 2009 that were 5 years old that looked brand new. Hope this helps.