How to find the DOT number on your tires
If you look closely at the side of each of your tires, you'll see a bunch of letters and numbers. While this may just look like a confusing jumble, it's actually useful info. Look for a number that starts with the letters “DOT,” followed by a series of 10-12 characters. This code, which is required by the U.S. Department of Transportation (DOT), will tell you several things:
Week, year, and place of manufacture
Tire size
Manufacturer's unique code