I noticed the Falken Azenis tires have a thread dept of 8/32", while the kumho ecsta 712's have 10/32", and ecsta MX lines vary from 8-9/32".

Does the thread depth have any impact on tire performance? Why can't the azenis tire use a 10/32" thread depth or larger for longer tire life?

 

More tread equals more heat build up in the tire, causing loss of handling/traction. Thats why you see street tires, that are shaved down for racing... Otherwise, the tread will just start melting... hehehe

 

In a perfect world, yes, less tread depth, less tread squirm, more responsive and stable tire.

With street tires though, as the tread wears down, the tire has gone thru so many heat cycles that the rubber gets harder and performance lessons. So even though an old bald tire has less tread than new one, it'll most likely perform worse.

But like 88_CS_CRX_Si said, shaving a new tire does help.

 

less tread also equals less tread squirm, one of the better reasons to shave a tire.