Recommended Tire Pressure for ST225/75-15 Trailer Tires

Updated 09/22/2025 | Published 06/20/2015

Question:

I have tire st 225/75d15 65 lbs max should they be 65? there at 40 now

asked by: Rick

Expert Reply:

Trailer tires should be kept inflated to the maximum pressure listed on the tire sidewall, as opposed to passenger vehicle tires that will have a certain acceptable range. If a trailer tire is inflated to a lower air pressure than the recommended maximum, the amount of weight that the tire can carry will be lowered. If a heavier load is put on the trailer tire than what is recommended for that air pressure, the sidewall of the tire could heat up and cause the tire to fail.

I'll link you to our trailer tire FAQ article that has additional information about trailer tires.

expert reply by: Mike L

Gary

6/17/2020

I have the same tires, I was told to fill tires slightly less than max to allow for tires adjust to hot temperatures. psi expansion I was told...

Walter S.

9/22/2025

Hey, expert Mike L, I followed your "inflated to the maximum pressure" advice (max 80 psi on sidewall), and now I'm sitting on side of road, waiting for a tow truck to fix my blown tire. Do NOT inflate to max on sidewall unless you enjoy changing tires or waiting for a tow truck. ??