Can Trailer Tire Size ST205/75D14 be Replaced with ST205/75R15

Published 07/18/2018

Question:

My trailer maybe 500 miles/year never go above 65 mph has ST205/75D/14. Can I use ST205/75R/14C to replace them?

asked by: Derrick A

Expert Reply:

The D in your current tire size means "bias ply" construction and the R in the size ST205/75R14 that you mentioned means radial which is the preferred style of tire. You can swap to this style of tire with the part # AM32156 that you mentioned and you'd have a better setup than what you currently have.

The main difference between a radial ply and a bias ply tire is how the tire is constructed. The cords inside a bias ply tire run at a 32 degree angle to the direction of travel, and the cords on a radial tire run at a 90 degree angle to the direction of travel, or across the tire from wheel lip to wheel lip.

A radial tire flexes more than a bias tire, giving it better ground contact, traction, stability, and tread wear.

A radial tire will normally run cooler than a bias ply tire, especially when the tire is under a load. A tire that runs cooler will last longer.

expert reply by: Jameson C