Now that I have posted my diatribe on the XPS rib, I want to go back to something we have discussed earlier with some new thoughts. The K factor, which is related to the intended service of the tire. We have learned that the K factor for trailer service is such that if you took an LT tire and replaced the LT on the sidewall with ST, the maximum load rating would automatically increase.
But there are two different values of K for LT tires. There is one for its use in single wheel applications, and one for its use in dual wheel applications. In dual wheel applications, the load rating is lower than in single wheel applications.
I have stated previously that I think the TRA needs to revisit the K factor for trailer tires, that the conditions of trailer service have changed in the past couple of years as trailers have gotten larger and larger. I think you could have one factor for a tire that is used in a single axle application, and another for the same tire in use in a multiaxle application. Likewise you could diffentiate between a high profile trailer and a standard or low profile trailer (the high profile trailers are subject to increased dynamic loading).
