Why Do Bias Ply and Radial Trailer Tires of the Same Size have Different Measurements

Updated 06/27/2014 | Published 06/26/2014

Question:

My boat trailer tire had a st175 80 d13 and i replaced it with a st175 80 r13 and the radial tire looked taller when i laid them on top of each other. should i put the same kind of tire on the other side? or will it be ok to pull with one radial and one thats not?

asked by: Chris L

Expert Reply:

It is not recommended to tow a trailer that has two different tire types on it. It will affect the handling and ride of the trailer since radial tires track better.

Any two tires of the same size from different manufacturers will have slightly different measurements. This is do to differences in manufacturing processes, tread type and wear, and amount of air pressure in the tires. Trailer tires should always be inflated to the maximum psi indicated on the tire.

Whether you stick with the bias ply tires or go with radials you will need to make sure that both tires are the same construction type. I have included a link to our informational article on tires for you.

expert reply by: Michael H