The average new tire has about 12/32 of an inch of tread on the tire, and once they have 4/32 of an inch left, it might be time to replace them. So, if the tire you are looking at is closer to 4/32 of an inch than 10/32 of an inch, it may not have much life left in it.
The simplest way to сheck the tread depth is to insert a penny into the tread with Lincoln’s head upside down; if you see the whole head, the tire is worn out. You can also use a quarter, a tread depth gauge, or look at the tread indicator on the tire.
One of the most important factors to consider when you are looking at used tires is the age of the tire.
According to manufacturers, after six years of frequent usage, the rubber starts to break down and dry too much. The US Department of Transportation suggests that ten years is the longest age for a working tire when it’s had excellent maintenance.
Usually, in the 7th year, the rubber starts to break down from exposure to the sun, weather elements, and road conditions, so be cautious and look for cracks from dryness.
Every tire produced after 2000 has a number that indicates the week and year the tire was manufactured. For example, 4309 means that the tire was made in the 43rd week of 2009. 2118 means that the tires were made the 21st week of 2018.
Use this numbering system to determine how old the tire is.
Once you’ve determined the remaining tread and age, look over the tires thoroughly for any defects in the seams.