Recommended Air Pressure on Trailer Tires That Are Not Loaded to The Maximum Load Capacity

Question:

Tires are rated at a max. load at a set air pressure. If the loaded trailer weight does not approach the combined max. rating of the 2/4/6 tires, is it still wise to fill the tires to the max. air pressure? Will this not just cause the centre portion of the tread to wear faster? James

asked by: James

Expert Reply:

We always recommend to run the maximum air pressure stated on the sidewall of the tire. That is the safest thing to do because then you have the maximum weight capacity covered for any type of load you will be hauling.

On the Kenda Tire and Wheel Assembly, part # AM3S870, you have referenced, the maximum load capacity for the ST225/75D15 tire is 2,540 lbs at 65 psi.

You can lower the air pressure in your tires, but that will lower the weight capacity of that tire. That would work fine if you are going to be carrying the same amount of weight on your trailer every time you tow it. The reason it is recommended to use the maximum air pressure is then you will have any type of load , large or small, covered on your trailer and not have to keep changing the air pressure in the tires.

If a heavier load is put on the trailer tire than what is recommended for that air pressure it will cause the sidewall of the tire to heat up quicker and cause the tire to fail.

As far as tire wear, the center part of the tread will wear faster when the tire is overinflated. That would mean you would have more air pressure in the tire than what is listed on the tire sidewall. This would cause the contact patch of the tread to lift on the edge of the tires and cause more pressure to be put on the center section.

I am including a link to a FAQ page on trailer tires.

expert reply by: Jeff D