Replacing A ST185/80R13 Wheel And Tire On A Boat Trailer

Updated 07/14/2022 | Published 07/12/2022

Products Featured in This Question

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

(1556)

$146.14

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

(675)

$144.53

Question:

Hi I need to get a spare tire and rim for my boat trailer. My current tire is a ST185/80R13. I’m see some tires marked that way and some with a D in place of the R. Could you tell me what the difference is? Thank You

asked by: Richard N

Expert Reply:

It is for the type of tire. Any tire with an R is a radial tire. If you see a D instead, such as the Loadstar ST185/80D13 Bias Trailer Tire w/13" White Modular Wheel - 5 on 4-1/2 - Load Range D, part # AM3S333, it is a diagonal or bias ply tire. Radial tires are more durable, so they last longer due to their superior belt construction. This is also why they are a more expensive tire.

You should never mix types of tires, so you should stick with a radial tire. My tire and wheel recommendation is the Karrier ST175/80R13 Radial Trailer Tire with 13" White Wheel - 5 on 4-1/2 - Load Range D, part # AM31985. It is a D load range tire, so it has a higher weight capacity, specifically 1,650 lbs at 70 psi.

I have included a product description link and a video review link below.

expert reply by: Mark Smith