Maximum PSI for Tires Size ST185/80R13

Updated 08/15/2017 | Published 08/14/2017

Question:

Inflating Pressures for ST185/80R13? How much do inflate this Radial Tire?

asked by: Jared P

Helpful Expert Reply:

The Loadstar ST185/80D13 Bias Trailer Tire # AM1ST79 has a maximum psi of 65. It is recommended that ST trailer tires always be inflated to the maximum psi as stamped on the tire's sidewall because that is where the manufacturers test for a weight rating.

Inflating tires to a lower air pressure than the maximum reduces the amount of weight that the tire can handle to an unknown amount, which can cause the tire to fail if a heavier load is placed on the trailer. Tires at maximum air pressure also perform and wear best (plus, you'll get better gas mileage). Over-inflating or under-inflating a tire also affects the way the tire wears over time.

The psi should be measured when the tire is cold—usually, first thing in the day is a good time. I've attached an article on trailer tires for you as well.

expert reply by: Amber S