I am trying to figure out the age of a deep-tread tire that looks good in a used vehicle.
The DOT number series ends in CBC 179 (Bridgestone).
As I understand things, since this is a 1999 car, the tire
was manufactured in 1999 – and should not be kept, even for a spare.
Is this correct?
It’s possible. Is that the only numerical code you found on the tire? I’ve certainly seen tires that old on seldom used motorcycles.
It should be week 17 of year 1999 (or 1989)
I can’t find any Bridgestone model number like that, but it could be. Any other 3 digit or 4 digit numbers on the tire?
For tires manufactured in the year 2000 – present
The date of manufacture is the last four digits of the DOT code. The first two digits are the week of manufacture, and the last two digits are the year. For example, if the last four digits of the DOT code are 0203, that means that the tire was manufactured during the second week of the year 2003. Pretty simple, right? However…if your tires were made before 2000, it gets a bit more complicated.
For tires manufactured before the year 2000
The date of manufacture is the last three digits of the code. The first two digits refer to the week within that year. For example, if the last 3 digits are 022, it means that the tire was manufactured in the second week of the year, and the year is the second year of the decade. This is where it gets confusing – there’s no universal identifier that signifies which decade, so in this example the tire could have been manufactured in 1982 or 1992. Some tires do have a small triangle following the DOT code to indicate the 1990s.
I’m going to go one tiny step farther than @BillRussell… focusing on IF you tires were made before 2000 when the date coding changed, THEN you should definitely replace these tires as they are 19 years old.
Any tire old enough to vote is too old to drive!
Yeah, I am basing it on the last digits that are in the series that starts with DOT.
And the logic in Bill’s post is what led me to the idea that it is about 19 years old.
Rubber degrades over time. Its better to be safe than sorry because you life is riding on them.
Since the whole DOT code wasn’t listed, we can only make an assumption about what was presented. There are lots of numbers on the sidewall of a tire and most have nothing to do with the age of the tire.
Further, some tire DOT codes have numbers in them that are NOT the date code. We need the whole code to make sure we’ve captured the date code (hint: DOT codes can be as short as 7 digits long or as long as 13 digits!)
Still further, we don’t know the context. What appears to be a 19 year old tire might not make sense on a 10 year old car.
Here is a story written by a CarTalk staffer and published at one of our partner publications that will answer your question about date codes and tire age issues. The easy answer to your post is “Yes” Too old.