So, in the comparison between similar LT and ST tires, testing shows the LT will survive a load of 3042 lbs for two hours, and the ST will survive a load of 3420 lbs for two hours. This test does not predict which tire will survive a 3000 lb load the longest in actual service conditions. The load rating on the tire is evidence that a statistical sample of the particular tire has consistently passed the two hour test at the indicated load. When you bring in variables like ambient temperature and speed traveled, the load rating is less of a predictor of performance for the long term.
This has all the makings of a fine Six Sigma project.
