What is the Difference Between Load Ranges for Trailer Tires

Updated 10/11/2013 | Published 10/10/2013

Question:

What is the Difference Between Load Range R and D ST175/80D13 Trailer Tires

asked by: Ed F

Expert Reply:

I cannot say I have ever heard of an R load range trailer tire. Generally, though, the further the letter is in the alphabet the higher the capacity is. If we look at size 175/80-13 then load range D tire # AM1ST77 that you referenced is rated for 1,610 pounds at 65 psi. A load range B in the same size is rated for 1,100 pounds at 35 psi. And a load range C of the same size is rated for 1,360 pounds at 50 psi.

I have included a couple of links on trailer tire sizes and tires in general. Ideally you want to match or exceed the capacity of the trailer when choosing tires. Going to a higher capacity or larger tire will not increase the capacity of the trailer.

expert reply by: Michael H