Can an ST185/80R13 Trailer Tire be Replaced with an ST175/80R13 Trailer Tire

Published 03/30/2012

Products Featured in This Question

Karrier ST175/80R13 Radial Trailer Tire with 13" Galvanized Wheel - 5 on 4-1/2 - Load Range C

(2390)

$140.72

Loadstar ST185/80D13 Bias Trailer Tire with 13" Galvanized Wheel - 5 on 4-1/2 - Load Range D

(7209)

$158.32

Question:

Hi - I currently have ST185/80R13 and load range C w/5 lugs on my Shorelander Trailer. Would this be an adequate replacement? Anything I need to consider or do you have any other recommendations? Thank you in advance

asked by: Greg

Expert Reply:

If the trailer is supposed to have 185/80-13 tires on it, then you should stick with that tire size and use # AM3S334. This is the correct size tire with a galvanized wheel. The only difference is this is a bias tire and not a radial. A bias tire the cords inside run at a 32 degree angle from the direction of travel and on a radial tire, the cords run 90 degrees across the width of the tire.

If you go with a smaller 175 tire and wheel combo, it will be about a half inch more narrow, and little over half an inch shorter than the 185. The biggest difference is capacity. The smaller 175 that you referenced has a capacity of 1,360 pounds at 50 psi. The larger tire that I recommend as a replacement to the existing 185 tires you have has a capacity of 1,710 pounds at 65 psi.

The smaller tire will fit but the capacity will be reduce by nearly 400 pounds per tire. It would be best to stay with the 185 size. I have included a link to our tire FAQ article for you.

expert reply by: Michael H