Originally Posted by BFlinn181
You're incorrect on the reading of your code example. The code was mandated beginning in 1980. A DOT code of 199 would be the 19th week of 1989. A code of 337 would mean 33rd week of 1987. From 1990-1999 the three digit code was followed by a triangle(Δ) symbol to show it was the 9th decade of the century so it wouldn't be confused with the previous decade. The DOT code for a tire made in the 19th week of 199 would be marked 199Δ.
If you find a 3 digit code, with or without the Δ, the tire is too old to safely run. That's why I didn't mention the older code system. If you find a 3 digit code, it's a tire made prior to 2000 and has been around at least 14 years old.
Ummmmmm, does make sense and don't remember seeing that triangle symbol on my original set and had one left for a spare up until last summer. Just goes to prove that you learn something new, each day.