Quote Originally Posted by SoonerFan View Post
OP did not state if tires were 14" or 15" or load range C or D?

My last set of tires were Carlisle 15" LRD that I understood to be speed rated to 99mph. I no longer have them but clearly remember it showing 99mph on the sidewall. It finally came apart one morning at just under 80 when I was trying to get to the lake before sunrise. 2 years old. Switched to Endurance....hope they're better than any other Goodyear tire I've ever owned.
The 99 you were reading is the load index, 99 = 1709 lbs. speed rating is marked with a letter. Also, some trailer tires require more pressure to run the max speed.