Should ST235/80R16 Load Range G Trailer Tires be Inflated to Max PSI

Updated 01/31/2023 | Published 01/30/2023

Question:

I bought 4 brand new cooper Hercules 235/80/16 tires for my fifth wheel. It says on the tire max inflation 110 they are G rated. I put 105lbs in them because I new they would go up in the road. But I have a tire monitoring system in my truck and with in 30 minutes on the road it said all of them were at 118-120 psi. Is this ok? Or should I lower my cold air pressure? Thank you very much.

asked by: Peter M

Helpful Expert Reply:

Size ST235/80R16 trailer tires should be inflated to their max - or very close to it - psi, so what you are experiencing is normal. We don't offer Hercules so I can't speak to those, but for example the Westlake ST235/80R16 Radial Trailer Tire - Load Range G # WE76FR also has a max 110 psi.

It is expected that the psi is going to raise when you get on the road, and the tire is built with that in mind. However, heat build up is also one of the reasons they have a speed rating, with the # WE76FR having a 75 mph speed rating, so you want to make sure you stay at or (ideally) a bit under the rating of your tire.

expert reply by: Kyle S