For tires made after 2000, look at the four-digit U.S. Department of Transportation code on the sidewall, notes Edmunds.com. The first two digits show the week of manufacture, and the last two show the year. A code of 1708 means the tire was made in Week 17 of 2008.
Tires manufactured before 2000 only have a three-digit U.S. DOT code. The first two digits refer to the week, but only the third digit provides information about the year. A code of 242 could have been made in the 24th week of 1992, but it could also have been from the 24th week of 1982 or 1972. Some tires in the 1990s feature a triangle after the three-digit code, but not all do, according to Edmunds.com.
If you can't find the DOT code, it's on the other side of the tire. The tire manufacturing process makes it safer to imprint the codes on the inner side. If you want to be able to see the raised numbers, ask the tire installer to put the raised numbers outward when you purchase tires or when you have them rotated. New tires come with the information on both sides per a requirement by the National Highway and Traffic Safety Administration, as stated by Edmunds.com.