tire mfg date?

[bergy]

I got a set of NOS G7014 red line tires with this GTO that I'm working on. They are old (USA made), but I'm not sure how old. There is a DOT impression just before the mfg/date code Aug 89? Oct 69? Any assistance would be appreciated.

[Lee Stewart]

https://i.postimg.cc/3WMfQyJF/65.png (https://postimages.org/)

[Crush]

Good info here. You probably already did this research . Probably 69
https://www.souzastireservice.com/Tires-101/Aging-of-Tires

https://www.cokertire.com/blog/tire-age

[Crush]

https://i.postimg.cc/3WMfQyJF/65.png (https://postimages.cc/)

This method started in 2000

[Burd]

What year did the dates start?

[bergy]

So, according to Coker web site - could be the 8th week of 1969. Since they are US made - I don't think they would be '79. '89' 0r '99. Could be wrong though. Anybody else have input?

[Lee Stewart]

Could you include a photo the the whole tire?

[bergy]

Looks like this tire was manufactured 8th week of 1979 (thanks Darrell). It can't be 69 because it is a DOT tire. Can't be 89 or later because the manufacturing went off shore in the 80s (this tire says USA mfg). Interesting to note though - the red line on these old tires is quite a bit narrower that then repro red lines - see pictures. Does anyone know if the narrower red stripe is available today?

[Lee Stewart]

This is for original, not repros:

Goodyear Polyglas Tire Date Coding

http://anghelrestorations.com/uploads/3/5/1/2/35122002/goodyear_polyglas_tires_v1.3.pdf

[bergy]

stripes on the NOS Polyglas tires measure approx 5/16 wide - repro Polyglas stripe width is approx 7/16 wide. Do the show judges out there pay any attention to stripe width in determining correctness?

[m22mike]

DOT tire marking started in 68 according to John Z @ CRG,

See reply 17 by John

http://www.camaros.org/forum/index.php?topic=12259.msg101589#msg101589

[bergy]

Interesting Mike - That opens the door for these tires being 1969 vintage. Since the universal code of 4 characters followed by 6 characters went in effect in 1973, my tires don't conform to that system - they are 4 characters followed by 7 characters. So, maybe Goodyear only coding prior to 1973?

[m22mike]

I believe the Goodyear codes are known. Check with Kelsey Tire 573) 346-2506

[Lee Stewart]

Looks like May 1971

https://ecfr.federalregister.gov/current/title-49/subtitle-B/chapter-V/part-574

[Steve Shauger]

Interesting Mike - That opens the door for these tires being 1969 vintage. Since the universal code of 4 characters followed by 6 characters went in effect in 1973, my tires don't conform to that system - they are 4 characters followed by 7 characters. So, maybe Goodyear only coding prior to 1973?




After May, 1971, DOT coding format was the same for all tires. 10 digit which included (3-digit date code WWY) I believe sometime after 1978 it may have changed to 11 digit). I need to do some research to confirm...



In 2000, and (12) digits (4-digit date code -WWYY)

[bergy]

Good info - when suppliers of big 3 OE tires had to indicate DOT (in the '68 model year per John Z) - they were not mandated to coincidentally add DOT to service replacement tires. So, there was a transition period between '68 and '71 (or '73 in practice) when each supplier of OE tires was mandated to add DOT, but could use their own codes for mfg/date. The universal mfg/date codes were mandated in '71 (or '73). What we're trying to establish is - whether Goodyear abandoned their old (pre '70) date code system and began a new system of their own on the OE tires between '68 and '71 (or '73).

In a nutshell - trying to figure out why the subject tires in this thread have an 8th week of year "9" manufacture date, but the mfg/date code doesn't conform to the federally mandated system post '71 (or '73). Does that imply that the tires were manufactured in 1969 (before the federal mandate went in effect)? Or, did Goodyear fail to comply with the federal system (if the date that these tires were manufactured was 1979)?

If anyone has pics of NOS G70x14 red line tires from '69 or '79 - please post them.

This may seem like a dancing on the head of a pin, but interesting (at least to me) to understand the nuances of manufacturing back then.

[bergy]

Steve - If you look at the pictures of tire codes in the articles referenced in this thread - the coding format post '71 is 10 digits. Or am I incorrect?

[Steve Shauger]

Steve - If you look at the pictures of tire codes in the articles referenced in this thread - the coding format post '71 is 10 digits. Or am I incorrect?


You are correct. May 71 To ? are 10 digit (I believe sometime after 1978, it changed to 11). Then in 2000 it changed to 12 digits.


Thanks Bergy, I will edit my previous post. I will dig for the transition date to 11 digits.

[Lee Stewart]

https://i.postimg.cc/RC8SQyk7/screenshot-8191.png (https://postimages.org/)

[Steve Shauger]

https://i.postimg.cc/RC8SQyk7/screenshot-8191.png (https://postimages.cc/)


Thanks ! I have a note with that date but finding it ... is another story.

[ssl78]

While we are on tire date subject anyone know what the date on this Firestone 7.75 -15 could be. There is no DOT warning on the tire could be a early repop

[Lee Stewart]

While we are on tire date subject anyone know what the date on this Firestone 7.75 -15 could be. There is no DOT warning on the tire could be a early repop

I am guessing: 26th week of 1970