Tire Age
Before 1990 I do not know
During the 1990's tires had a 3 digit number in a block to tell the year.
After the year 2000 tires have a 4 digit number in a block to tell the year
Below are some samples of tire markings and age
Number Week Year
In Tire Tire
Block Made Made
185 18 1995
188 18 1998
231 23 1991
414 41 1994
459 45 1999
466 46 1996
608 6 2004
808 8 2008
1005 10 2005
1506 15 2006
2610 26 2010
3101 31 2001
3407 34 2007
4202 42 2002
4302 43 2002
4808 48 2008