Its the second car does 2k miles in a yr - just local drive.
WHat is the thread measure to change tires (legal)?
There is tread depth (legal), and there’s also tire age (not legal, but important). Both are important.
Please tell us what car you’re talking about. Year, make, model, and any options.
How old are the tires now?
The legal tread depth is 2/32 of an inch in most places (down to the indicator built into the tire). However, if you wait until the very end, you’re at some risk of hydroplaning on wet roads, and you definitely don’t want to use such tires in snow.
I replace mine at 4/32 in summer and 6/32 in winter.
Its driven in Northern CA.
Generally I would say that six years is the maximum for tyres. After that they become un-reliable. However if you live In an area where the ozone is low and if your car is usually not in the sun, they may be OK for a few more years. It's up to you and it is difficult to tell just by looking if they are good, but if there are cracks in the sidewall you know they are bad. I would be more worried if I drove on the freeway.
Get a penny and find the shallowest tread on each tire. Stick the penny in upside-down. If any of Lincoln’s head is covered, you are still OK. The closer you are to seeing all of Abe’s head, the sooner you will need to replace the tires.