I'm not a tire expert.
The simple way I look at it is....
LT225/75R16 115/112R <---- E-Rated load tires that come stock on most 30' Class C RVs. Very little load carrying buffer, especially if not cold inflated to 80psi.
vs
LT225/75R16C 121/120R <---- What I am calling "Commercial tires". (the 121/120 load rating is what you are looking for if you want more weight carrying capacity). These give you ~2000lbs of extra load carrying capacity on the rear axle. I put them on the front also.
You should never overload your rear axle per the amount on the sticker on the driver side door jam. The "extra" buffer, in my mind, especially comes in handy due to the fact that people (myself included) sometimes drive on tires that are less than cold 80psi inflated.
Just what I do and what I would recommend to family/friends.
Safe travels!
Chris
