You can learn some facts about Max tire pressure by reading your tire

I found significant discussion on tire 'maximum pressure" on a forum thread on a new Michelin tire. One problem is that the new tire is not yet available in the market so getting confirmation on what the tire has for markings on the sidewall was based on second hand information from various Michelin sources. Despite these problems I felt it might be instructive to review the relationship between load capacity and inflation pressure.

The following was posted:

The Michelin LTX M/S2 P235/75R15XL 108T carries its rated load at 41 PSI. Yet the maximum pressure stated on the tire is 50 PSI. There is no load capacity increase above 41 PSI.
Tire Rack has a good explanation of the maximum load for a tire
Tire Tech Information - Tire Specs Explained: Maximum Load

As I have previously reported the numbers associated with the "complete" size nomenclature are very important. In the above thread there were a number of readers confusing the inflation associated with the max load capacity with a statement on the tire about safety and tire inflation. When discussing Load and inflation it should be easy to read the tire as the max load and the inflation needed to support that load are clearly stated together.

There is also a "Safety Warning" on many passenger and similar info on LT tires that includes a statement about "max inflation" but that number is really the max pressure that should ever be used when inflating a tire to ensure proper seating of the tire bead against the rim. This number is not associated with the load carrying capacity of the tire.

Here is a sample Safety Warning from a Performance 16" passenger tire



Here is the Load and inflation information, again for a passenger tire



Now while the above are from a passenger tire that was convenient for me to get pictures of, I know that you should see similar on your ST or LT type tires.

I think you may learn a bit more about your own tires if you take a moment to read the information provided. Knowing what tires say on the sidewall can help avoid making mistakes when assumptions are made.

 It might be a good idea to take a few minutes to go and read your tire sidewall. You might be surprised what you can learn.


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