average tread depth of new tires
With Bad Weather on the Horizon, Now's the Time for New Tires. While most passenger car tires come new with at least 10/32 of tread depth, most people don't realize that once the tire has less than 6/32 of remaining depth, your wet road and snow traction capabilities dramatically decrease. Even if the tire looks like it has plenty of life left, do yourself a favorâ¦.
The two horizontal lines in the lower half of the plot represent two criteria for specifying the lifetime of a tire. The lower curve represents 2/32, the legal limit in most states for minimum acceptable tread depth and the height of tread wear indicators built into the tire. This depth corresponds to the common Lincoln head penny test. The second line represents 4/32, a depth that may represent a safer minimum. The first plot shows the actual measurements of the tread thickness. I've had the tires rotated twice and there's an obvious change in the wear rate at each rotation.