If you want to know what tires to get for your RV, I can tell you that as a Tire Design and Forensic Engineer, the most important feature is that is it rated to support the weight you are placing on the tire when the tire is inflated to the level you set it for.
The Max load is spelled out on your certification label affixed to your RV and is stated as "GAWR" which is the max load ever allowed on an axle. BUT it is important to remember that the tire load capacity depends on the "cold inflation" you set the tires to. If you do not have at least that level of inflation when you drive down the highway you will be doing damage to your tire.
The MINIMUM inflation you need to achieve that load capacity is also clearly stated on the label.
These inflations are the "cold" inflation you set your tires to BEFORE you start driving and you should never bleed down the psi after you start driving each day.
I hope this helps answer some of the questions I see in many RV forums.
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