H vs T speed rating for tire replacement

Interestingly enough on wear rating IMHO its completely worthless. My Subaru OEM Bridgestone RE92’s (215/45ZR17) have a treadwear rating of 160AA. The tires are about 3/4 worn at 40k miles. The Bridgestone G009 which are rated 50k have a treadwear rating of 460AA. Maybe its minimum?