Tires: Which Ply for what application, proper inflation pressure, 1 ton trucks

Question
I am a Safety Professional with very little knowledge about tires and due to a Management decision being made regarding the tires of our fleet vehicles, 1 ton trucks that haul bob-cat trailers all over the country to well sites off road on track leases and back.  The 1 ton trucks can haul up to 10,000 lb loads.  They have been using 10 ply tires and are beigh instructed to replace them with less expensive 4 ply tires.  My concern for the driver and all those who could potentially be affected, I am looking for the technical manufactures data on how to know what is safe and what is not.

Answer
Jack,

I think you may be confused.

First, it's all about load carrying capacity - not plies.

Every light vehicle sold in the US  has a placard that indicates the original tire size and the proper inflation pressure for that size.  That information equates to a load carrying capacity, and this should not be reduced without very careful consideration.  So I suggest you start there.

But 1 ton trucks typically have Load Range E tires, so called 10 ply tires.  In fact, these tires do not have 10 actual plies, typically it is 4 plies - 2 polyester and 2 steel belts.

So you need to look for 2 things:

1) The vehicle placard and what it says there for size and inflation pressure.

2)  The new tire size and load range.

Post back if you need help sorting  this out.