“When a tire is brand new…” , too generic.
A tire, which tire ? precisely , brand and tire name.
I have a warehouse with 300 tires in inventory. NEW they vary from tire to tire. The samples I took just now, 9/32" all the way to 1/2".
Tell us exactly your tire type, size, brand name, tire name. Or, knowing that, visit the website for that brand to view their specs.
Miles driven on a set of tires is , again, entirely variable from tire to tire.
The rubber composition ( the recipe they use when they mix up the batch of rubber ) is different for each brand AND each tire line within a brand.
There is no simple, single answer.
Customers come to my parts desk and say they want some tires for their truck.
“What size?”
“uh, 17s”
“what size 17s ?”
( deer in headlights look )
After researching the size I show them a list with 40 different tires on it and get these huge eyeballs looking back . And that’s just the list of tires in the Ford dealer program, not including all that are out there somewhere else.
( I’ve stopped showing the entire list now, and just discuss the ones in stock vs the type they want. Much easier. )