Tires: question about tire sizes inlcuding PLYs, tire failure, plys

Question
What is the main difference between a 10ply and 12ply tire? I am trying to purchase tires for a 1990 motorhome that gets about 200 to 300 miles a month. 10 ply tires can be bought for about 40 dollars cheaper (apiece) compared to 12 ply tires.

Thanks you,
Jesse


Answer
Jesse,

The difference is that a 12 PLY RATED - also known as Load Range F - is capable of handling a higher load at a higher pressure.  For an RV this is cheap insurance as you do not want to have to deal with a tire failure and using a higher load range decreases that risk.