Ever wonder what the numbers on the side of your car's tires mean. Here is some interesting information. There is a number imprinted after the initials DOT (US Dept of Transportation) the last four digits of the number tell you when the tire was manufactured. For example, 2113 means the 21st week of 2013. the word treadware suggests the projected milage that a tire will give you. there is a three digit number after the word Treadware to estimate the milage projected muktiply that number by 2 and add two zeros. For example, 200 x 2 = 400 + 00 = 40,000 miles.