Hi everyone, I removed the rear wheels preparatory to changing the timing belts on my August 1988 328. Out of curiosity, I tried to decode the "date code" from the Goodyear Eagle 225ZR50 tires but cannot seem to make sense of the code. Sidewall reads: DOT M60H FCOR 224 0727 That's all, no triangles or other character markings. Given that the car has 10K miles, there is a possibility these are the original tires (?), in which case I would obviously want to replace. Thanks for your time, Carl
The first two digits after DOT are the plant code. M6 THE GOODYEAR TIRE & RUBBER COMPANY LAWTON OKLAHOMA US Since 2000, the last 4 digits are supposed to represent the week and year of manufacture, but usually the week is followed by the year.
I am not sure that this is the line of code that contains the date. Seems to have too many characters. In addiiton, in the date code the last two digits signify the year within the decade, i.e. should be 00 - 09; so 27 doesn't work. http://a257.g.akamaitech.net/7/257/2422/16nov20071500/edocket.access.gpo.gov/cfr_2007/octqtr/pdf/49cfr574.5.pdf
Prior to 2000, it was a three digit number. First 2 digits are the week, and the third is the year of the decade of manufacture. I haven't looked at tires in a very long time, but aren't they currently 12 digits (including optional group). 9 and 10 being week, 11 and (12 since '00) the year. That would make it the 224. 22nd week of 94 (since car is '88 m/y). You could always go to a Goodyear and ask.
Thanks everyone (and great reference Bryan). After doing an online search regarding DOT methadology...I couldn't figure it out either. Here's a picture of the inner sidewall with contrast improved (small circular marks beside numbers look to be production shift time clocks?): I've owned the car since 11/02, and have not fitted new tires in the interval. I'm thinking replacement may be wise at this point. Thanks again, Carl Image Unavailable, Please Login
You are 4/7ths correct. Weeks are full weeks, so the first week of 1994 would be the first full week. Sunday Jan. 2 through Saturday Jan. 8. The 22nd week would be Sunday May 29 to Saturday June 4.
I think you all are missing the facts. Carl stated that he purchased the car in 92' and has not fitted new tyres. Therefore, how could he have tyres that were manufactured in 94'??
Even if the tires were new in '02, with modern summer performance compounds, it might be about time for new ones. If they're from the '90s, they're way due. I checked four sets of tires in my garage and they're all four digit date codes (xx01, xx02, xx03, xx06). And I've been figuring it's about time to replace some of those: The '03 Yokos have maybe another season on the tread, and after that they'll be old. The '01 S03s are about due, from age alone (plus there's a nail in one of them). (The '02 Nokians were already replaced with the '06 Contis -- but that was road damage to one of the set. Just where does that highway tax money go, anyway?) A set of modern summer tires is one of the cheapest performance upgrades you can give a Ferrari. Whatever the car does has to be translated through the tires' contact patches. So they don't cost much but they matter a lot. You should look into a set of new tires -- there are better performing tires than Eagles, these days. If you haven't had a full four-wheel alignment on the car yet, you might want to have that done at the same time.
This sums it up pretty much, handy to copy/paste and save it where you can easily access: To determine a tire's age look on its sidewall (usually the back side) for the letters DOT followed by one or more ovals containing numbers. The last oval will have three or four digits. If there are three digits, the first two are the week of the year and the last digit is the year of manufacture (the digits 229, for example, would indicate the tire was manufactured in the 22nd week of 1999). To distinguish between the 80 and 90 decades, tires manufactured in the 90's will have a triangular mark to the right of the manufacture date. Beginning with the year 2000 there are four digits. The first two are the week of the year and the last two are the year of manufacture (2301 indicates the tire was manufactured in the 23rd week of 2001). since I don't see a little triangle, I'm going to say 22nd week 1984......
Not every tire manufacturer used triangles and 'shapes'. The reason why, prior to 2000, that a 3 digit code was used was because DOT assumed a tire would not be in service after 10 years.
Here is a video link from the Today show called Todays 101, The Dangers Of Aging Tires. http://www.msnbc.msn.com/id/21134540/vp/24576402#24385155 The video is pretty much telling you to not drive on old tires like six or ten years old. But, they also say there is no expiration date on a tire so it's up to you to determine if it's too old. Any and all webs site links will eventually die out. So I decided to do a Print Screen of the Tirerack info found in the link below. http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=11 Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
