Tires: passenger car tires, passenger car tires, tire markings

Question
To Barry: to answer your question-- as to why the interest in THESE markings. The particular markings I am asking about are the only ones that have not been identified.. I believe that your explanation of the "R" and "K" identifying the mould, etc. are probably correct..
The one I am really after is the 63R and 63L.

The tires do have a MAX LOAD LIMIT (1279lbs)listed on the sidewalls  but I cannot find any speed rating on the tire.
Is it possible that the tires  may have been reworked (i.e. remoulded, recapped, or repaired in some way) and had to be "rerated" and thus the 63R and 63L would have been applied and the old speed rating markings removed?  [May not make sense because the load rating is still there...]

And if the tires have been reworked in some way, are they now safe for normal use on a car? [My daughter travels a fair amount on the 401 highway here to visit us every weekend and if these tires are not rated for proper speeds...)

I probably would not be as concerned had my wife not told me the story about the lady who purchased 4 brand new tires only to have one of them blow up on her on the highway. It turned out that the tires were in fact retreads and not new at all...




Question -
what do these tire markings mean:
R-42515  K-33013     63R  DOT PLC6 F5KR 4905
These markings appear on my duaghter's new tires on her 2003 cavalier). One tire has 63L instead of 63R before the DOT code.
I am interested in knowing what R-42515, K-33013, 63R, and 63L mean and why one tire would have a different marking. Note these markings are on the inside sidewall of each tire located within the smaller band nearer the rim. The outside sidewalls repeat most of these markings except that K-33013 is replaced by K-32923.
There is also a barcode "sticker" that seems to be embedded or cemented in place on the outside sidewall at the rim area.
My daughter was told that 63R was a service description but that doesn't seem to make any sense.  Isn't that kinda low for a car? Hope you can be of some help to us.  Thank you
 


Answer -
First, everything after the letters "DOT" is the Tire Identification Number, commonly called the serial number.  The first 2 letters are the plant of manufacture (in this case Kelly-Springfield in Tyler, Texas)  The third and fourth digits are the tire size (I don't have the code book in front of me, but I think this is a P195/65R15)   The next 4 digits (F5KR) are assigned by the tire manufacturer and are optional as to whether they appear or not, but commonly there are 3 or 4 digits.  This would identify the particular tire design.  The last 4 is the date of manufacture in a week/week/year/year format - 49th week of 2005.

The letters "DOT" mean the tire meets all US standards as set by the Department of Transportation.

The other markings are probably related to mold identification.

The "K" number, since it appears in the same form, but with a different number, probably is the serial number for that particular mold half - which would be different for each side.

The "R" number probably refers to the drawing that describes the mold.

The 63 R and 63L are not the Service Description.  The Service Description should be 89S or something similar and should appear immediately after the tire size.  The R and L would seem to be left and right, but that does not make sense as I know that Cavaliers won't have assymetrical tires - GM wouldn't allow it except in special cases like a Corvette.  And it certainly doesn't mean left and right side of the car - GM wouldn't allow that either.  Perhaps the R and Left are left and right sides of the curing press, but that also doesn't make sense.  

But the big question is:  Why are you asking?  There are a lot of other markings on the sidewall and I'm sure that those haven't been identified for you, so why these particular sets of markings.

Just a guess on my part, but the car has a pull and you want to know if it is related to the tires being different in some way.  

Answer
The fact that these tires were produced in 2005, makes me think they aren't retreads.  Besides, retreading passenger car tires is unheard of (too expensive compare to the cost of a new tire), and while I don't want to doubt what your wife heard - I really think something else happened.

But you still haven't been clear about why you are so interested about the markings on the sidewall.  Is it just concern about your daughter's safety?  Then the solution is to buy tires that you are confident in!