Correct Tire Pressure for Trailer Tires

Updated 09/12/2025 | Published 05/26/2025

Question:

I have a 2020 Haulmark passport cargo trailer 8.5x16ft. the factory tire size is ST205/75R/15C 6ply tires at 50 PSI on the factory sticker. I bought from etrailer.com several years ago Ranier ST205/75R/15D 8PLY tires. so now my question what tire pressure do I run? thank you

asked by: Roger D

Expert Reply:

Hi Roger; the tires I see in your last order are the Contender ST205/75R15. It looks like the wheel and tire you ordered was discontinued but I can tell you that the max psi for that tire was also 50 psi. It sounds like you have different tires now since they're Rainier.

One way or another, you need to follow the max psi on the actual trailer tire. The sticker on your trailer only applies to the factory tires that came with the trailer. Once you swap those out you need to adhere to what is listed on the side of the tire from the tire manufacturer. If they said 70 psi like the # KE34WV you looked at and you followed the 50 from the factory trailer sticker it would lead to an unknown capacity and potentially a blowout.

If you have any other questions don't hesitate to reply below.

expert reply by: Robin H

Contender ST205/75R15 Radial Trailer Tire
(click to enlarge)

Robin H.

9/12/2025

Hey Roger, did you get a chance to check the side of your Rainier tires for the correct psi? I want to make sure you're set up safely for your travels!