The Correct Trailer Tire Air Pressure for Brand Name Trailer Tires  

In a question asked by Eli about how to Determine the Right Air Pressure to Fill a Trailer Tire, helpful expert reply by: Michael H stated: I can end this debate for you real fast! Trailer tires, which will have an ST in front of the size, should always be inflated to the maximum psi indicated on the tire. I respectfully disagree. Stating max inflation on a trailer tire is akin to stating you should put max inflation in your car tire instead of what the label states affixed to your car. If you use max tire inflation you will probably over inflate your tire which will cause it to wear unevenly in the center and not allow the full/proper contact patch of your tire. Now it is true that the pulling vehicle tire requirements are different than a pulled trailer. That is why a ST tire is made differently than a car tire. However, many sources state different inflation requirements for ST tires. I have included a few links for you to look at. Some are from tire manufactures, such as Goodyear, that give inflation guides for their ST tires. I will agree that if you have no idea what your load will be it is better to over inflate max tire pressure for your particular load than to under inflate which could cause tire failure over a long distance. As for me, I have a good idea as to how heavy a load I am carrying, Scag lawn mowers, Skid steers, etc. so I inflate my tires according to the charts. If I do not know for sure what my load will be I will estimate the weight and inflate to a slightly higher range. If I am wanting to use the full weight capabilities of my dump trailer then I use max inflation. But I submit that if you are delivering a 500 lb lawn mower to your mother who lives 100 miles away in a trailer that can carry 5,000 lb , max tire inflation is overkill. Depending on how well your trailer is made and the condition of the road, you may find you will have to reassemble the lawn mower after you arrive.

asked by: Larry G