Every tire carries its own birth date, stamped right on the sidewall. It is part of the DOT code — the string of letters and numbers that starts with "DOT" — and the last four digits tell you the week and year the tire was made. Knowing how to read it matters because tires age out even when they still have tread left, and plenty of vehicles on the road are rolling on rubber that is older than their owners realize.
Finding the code
Look for the letters DOT on the sidewall, followed by a series of characters identifying the plant and the tire. The full code is usually on the outer sidewall of at least one side; on some tires the complete code, including the date, is on the side facing inward, so you may have to check both sides or get down with a flashlight.
The date is the last four digits of the code. The first two are the week of the year the tire was made, from 01 to 52. The last two are the year. So a code ending in 2319 means the tire was built in the 23rd week of 2019. A code ending in 0424 is the 4th week of 2024. That is all there is to it — no chart required, though we have a free DOT date decoder on our Tire Tools page that does the math and tells you the tire's age.
Why age matters when the tread looks fine
Rubber changes as it ages. Heat, sunlight, and oxygen slowly harden the compound, and tiny cracks develop in the sidewall and between the tread blocks. A hardened tire does not grip like a fresh one, especially in the rain, and aged rubber is more likely to fail — a separation or a blowout — than a younger tire with the same tread depth.
That is why a low-mileage vehicle can still need tires. The truck that only makes short runs around Glasgow, the car that sat in a barn for two years, the camper-season vehicle — their tires can be seven or eight years old with tread that looks nearly new. Tread depth says how much rubber is left. The date code says how good that rubber still is. As general guidance, vehicle and tire makers commonly suggest having tires inspected closely once they pass about six years of age, and replaced by ten years at the latest regardless of tread — sooner if cracking or damage shows up.
The tire everyone forgets: the spare
The oldest tire on most vehicles is the spare. It was often made the same year as the car, rides in the trunk or under the bed for a decade, and never gets looked at until the day it is needed — at which point it may be a twelve-year-old tire being asked to do a new tire's job. Check its date code too. A spare that has aged out should be replaced or, at minimum, treated as a short, slow trip to the shop rather than a normal tire.
The same check matters when buying. A "new" tire that has been sitting in a warehouse can be a couple of years old before it is ever mounted, and a used tire's real value depends as much on its date code as its tread — something we covered in our guide to buying used tires.
Reading yours in the driveway
Checking your tires' ages takes five minutes: find the DOT code on each tire, read the last four digits, and run them through the decoder on our Tire Tools page if you want the age figured for you. While you are down there, look at the sidewalls for cracking, bulges, or weather checking, and check the tread for uneven wear.
If a tire is old, cracked, or you are not sure what you are looking at, bring it by. At Southern KY Tire Pros we will read the codes with you, check the tread and sidewalls, and give you a straight answer on what is safe to run — and if you do need tires, remember we sell more brands than we can list, and most of what you find online we can usually get for a better price, installed. You will find us at 1004 Happy Valley Rd, Glasgow, KY 42141 — call (270) 861-2003 or text (270) 320-7359, Monday–Friday 8:00 AM–5:00 PM. Start at our Shop Tires page.