22k miles on a 2013 built 2014 Winnebago. 22k lb. chassis. Keep tires at 90psi (recommended) and service checks before long trips. Have seen comments that tires generally need replacement if years...
Manufacturers recommend INSIDE inspection yearly after 7 years. This means the tire has to be dismounted to check for separation 'issues'. Given the hassle and cost of dismounting etc. I simply budget for replacements every 7 years. YMMV..Dennis