Tires: Tire ply, radial truck, truck tires

Question
When a tire is 10 ply does that include the side wall as 10 ply.

Answer
Charles,

The correct term is "Ply Rating" and it is a term that has been replaced by "Load Range", because some folks think that a "10 Ply Rated" tire ought to have 10 actual plies.  That is not the case.

The strength of a tire comes from the materials used and not the number of plies.  For example, Medium Radial Truck tires - the kind used by 18 wheelers - has a single ply.  It's made of steel cable, but it is a single ply.  If the same tire were made of nylon, it would have 8 plies, but be called a Load Range F (12 Ply Rated).