Since 2000, DOT-legal tires have been required to have a date code like this. The first two letters after “DOT” here are the plant’s code, the third and fourth letters are the tire size code, and the fifth through eight letters are the manufacturer’s code. However, those eight middle ones can show up as either letters or numbers. If you don’t do your own tire changes, this is important because many tire shops won’t touch a tire that is more than five years old. Look for the “DOT” and the letters that follow that. The last four numbers are the most important, indicating the week and the year in which the tire was made. In this case, this tire was made the 17th week of 2012 (1712). While this code is 12 characters, some might only be 10. Again, look for the last four.