Tire questions & tire date codes

[Gary S.]

I am trying to find out if there is an available data base for deciphering the codes by the DOT stamp on four 1972 Goodyear Speedway Wide Treads without the white letters or white stripe. Three of them have identical alphanumeric codes while one has a letter code only. Confusing, to say the least. Would the same codes be used for Firestone's or are these company-specific codes? I also have an, apparently unused Firestone Wide Oval, with white letters that has most of the original factory markings. I would like to decipher that code too.

Secondly, the 1970-72 TIMJG talks about the standard Firestone and Goodyear tires, with descriptions of tread width, sidewall wording, and such. Then it goes on to describe that the Firestone has nine ribs but no mention is made of the Goodyear Speedway's. After this discussion in the text, the TIMJG goes on to talk about the white stripe or raised white letter optional tires.

Finally, the paper tag that is mentioned in the JG is present on three of my tires. Do the numeric codes indicate julian dates or something else?

Thanks

Gary
ps, off line email is fine

[Dave S.]

Re: Tire questions & tire date codes

Gary, There is lots of information on this in the archives. Terry Mc. has a wealth of knowledge on this subject and has shared it with this board. Around January of 1971 the tire manufacturers went to a universal "long" code which still exists today. The last 3 digits are the week and year. For instance my 71 original tires have the last 3 digits of 171, for the 17th week of 1971. The VIN of the car is #16798. Earlier codes are a bit of a mystery, but by having the "short" code you know they are pre January of 1971.

[Duke W.]

Re: Tire questions & tire date codes

I'm not sure about early seventies tires, but the DOT codes on current tires usually consist of a series of letter followed by a three, and recently four
digit date code.

The letters are company specific and identify the tire model and plant, and
I don't know how to decode them, but the three or four digit numeric code
that follows the letters is the week (1-52) and last digit of the year for
three digit codes.

In the last couple of years the industry has started using the last two digits of the year. Thus the four digit code, and now you don't have to guess
the decade.

Duke

[Gary S.]

Re: Tire questions & tire date codes

Perhaps I need to sharpen my skills on the archives search. I came up with lots of stuff but not codes. I will give it another try.

Thanks guys,
Gary