AboutBarry Smith Expertise I have over 30 years experience in the design, manufacturing, and
testing of tires. I have served as the technical advisor to the "800"
number. I have authored or co-authored many publications - usually
without credit. I can answer almost any technical question, but
please don`t ask me to compare brands. I probably have prejudices because of
my work experience.
Experience Member SAE (Society of Automotive
Engineers)
Member Tire Society (Tire Technical Organization)
SCCA Regional Competiton License holder
Authored many training manuals on tires, their care and use.
Expert: Barry Smith Date: 7/11/2008 Subject: Date coding
Question Hello Barry, Thanks for taking the time to look at my question, I have two older GoodYear Eagle ST tires they are new old stock with the following information P255/60R15 Date code G05R DOT MKUT 2BO 287 Can you explain what all those letters mean? I saw in a previous question the MK is the place of manufacture Union City Tennessee and the UT was the tire size but what is all the preceding alpha/numeric code for? is this tire manufactured in 1977 or 1987? I'm quite sure it was not 97 as i acquired them in 99 and they were stored for many years at that time.
Thanks for any information you can provide
Best regards,
Ken
Answer Ken
The DOT codes consist of a 10 to 12 digit number that appear in the immediate vicinity of the letters "DOT"
The first 2 digits are the manufacturing plant. In your case MK = Goodyear, union City, TN
The next 2 are the tire size in a code. UT = ??, This should translate into P225/60R15, but I don't have a list of what the codes mean.
The next 3 or 4 are a code assigned by the tire manufacturer - 2B0
The last 3 or 4 are the date of manufacture in a "week / week / year" or a "week / week / year / year" format. The transistion to a 4 digit code started in the year 2000. In your case 287 means 28th week of 1997 (or 1987 or 1977) - probably 1997. Tires produced in the 1990's usually had a sideways triangle that was supposed to look like an arrow pointing to the date - like this <|
My best guess is that Eagle ST were not produced in the 1980's so that means your tires are 11 years old and based on recent announcements should not be used. Rubber degrades over time - even if the tires are unused - and while there is some disagrement on when the limit is, everyone agree that 10 years is for sure too old to use.
The stuff before the DOT code is specific to Goodyear and only they can tell you what it means - but don't be surprised if they can't or won't. Some of this is proprietary information.
