What Does Ply Rating Mean on ST Trailer Tires?

Published 10/05/2018

Products Featured in This Question

Kenda 215/60-8 Bias Trailer Tire with 8" White Wheel - 5 on 4-1/2 - Load Range C

(7669)

$81.80

Kenda 215/60-8 Bias Trailer Tire with 8" White Wheel - 5 on 4-1/2 - Load Range D

(7669)

$85.59

Question:

which is better 4ply 6ply or 8ply and what does it mean and why?

asked by: LA

Expert Reply:

The ply rating has to do with the thickness of the tire and the load capacity will increase based on the ply rating. The information below tells you the ply rating and general load pressure (in psi units) determined by the manufacturer testing:

Load Range B: 4 Ply Rating, ~35 psi
Load Range C: 6 Ply Rating, ~50 psi
Load Range D: 8 Ply Rating, ~65 psi
Load Range E: 10 Ply Rating, ~80 psi
Load Range F: 12 Ply Rating, ~95 to 110 psi
Load Range G: 14 Ply Rating, ~110 psi

The Kenda 215/60-8 # AM3H310 you asked this from is a 6 ply rating with a load capacity of 935 lbs at 50 psi. If you want a higher capacity, you can use the Kenda 215/60-8 Bias Trailer Tire with 8" White Wheel - 5 on 4-1/2 - Load Range D # AM3H323 which will give you a stronger tire rated for 1,165 lbs at 70 psi with a ply rating of 8.

Better is determined by the capacity for your trailer load. Underrated tires will wear unevenly, overheat and eventually fail. Overrated tires will give you a rigid ride and may lead to loss of traction due to bounce. You want tires rated for your trailer load and your axle capacity.