1970 tire date codes

[D S.]

I have no clue how to decipher dates on 1970 tires so here I am again seeking information.

Goodyear Polyglas GT F70-15
MDU2 Y4A033

Goodyear Custom Wide Tread Polyglas F70-15
MBU2 DMA 201 DOT

Are the first four characters the date?

Thanks,
Scott Sims
Texas Chapter

[Patrick H.]

Re: 1970 tire date codes

I have no clue how to decipher dates on 1970 tires so here I am again seeking information.

Goodyear Polyglas GT F70-15
MDU2 Y4A033

Goodyear Custom Wide Tread Polyglas F70-15
MBU2 DMA 201 DOT

Are the first four characters the date?

Thanks,
Scott Sims
Texas Chapter

Scott,

Google is your friend:

Tire Rack:

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=11

or, just search "tire date" on this site.

https://www.forums.ncrs.org/showthre...+date&uid=9042

[D S.]

Re: 1970 tire date codes

I was hoping the TDB would be, too. I'm the kind of person who likes to see deciphering of the numbers/letters, if possible. I visited both links and am still as unenlightened as when I posted this. What I would like to know is this: Using the information I posted would those tire names and "dates" be correct for a spare in 1970 Corvettes? I know the rims are judged by dates but are the tires? If not then the question is moot. The 1970-1972 JG on page 50 describes various tires by brand and size but does not mention dates.

[Dave S.]

Re: 1970 tire date codes

I was hoping the TDB would be, too. I'm the kind of person who likes to see deciphering of the numbers/letters, if possible. I visited both links and am still as unenlightened as when I posted this. What I would like to know is this: Using the information I posted would those tire names and "dates" be correct for a spare in 1970 Corvettes? I know the rims are judged by dates but are the tires? If not then the question is moot. The 1970-1972 JG on page 50 describes various tires by brand and size but does not mention dates.

I don't know if 15" Goodyear polyglass tires were made in 1970. If they were they did not come on Corvettes.

[Dave S.]

Re: 1970 tire date codes

I have no clue how to decipher dates on 1970 tires so here I am again seeking information.

Goodyear Polyglas GT F70-15
MDU2 Y4A033

Goodyear Custom Wide Tread Polyglas F70-15
MBU2 DMA 201 DOT

Are the first four characters the date?

Thanks,
Scott Sims
Texas Chapter

Best I can tell one tire is dated the third week of 1973 and the other is the 20th week of 1971 which is the early stages of the longer tire codes requested by DOT. During the first 1/2 of 1971 is when the "long" codes were introduced.

[Patrick H.]

Re: 1970 tire date codes

Best I can tell one tire is dated the third week of 1973 and the other is the 20th week of 1971 which is the early stages of the longer tire codes requested by DOT. During the first 1/2 of 1971 is when the "long" codes were introduced.

Exactly.
And, you can determine this using the links I provided. Look at the "Tires made before 2000" section on the lower portion of the Tire Rack page.

The Polyglas was never used on the Corvette, so they're not correct spares even if the dates were right.

[Steven G.]

Re: 1970 tire date codes

Scott, My early 70', vin. #09, spare is a Good Year F70-15 Speedway Wide Tread, URO1BO8, V-1, also #225090-2WN. I know nothing about decipering the numbers or letters, but I believe it is the factory original tire, hope this may help. Steve

[Michael W.]

Re: 1970 tire date codes

Scott,

Google is your friend:

Tire Rack:

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=11

Thanks for the link Patrick. I'm the type that likes to 'learn how to fish'.

[Scott G.]

Re: 1970 tire date codes

1970 and prior tires did not use a standard federal coding system. Prior to the federal system coming in each manufacturer had it's own system.

[D S.]

Re: 1970 tire date codes

Thanks to all for the links and input. According to the 1970-1972 JG polyglass tires weren't included. Goodyear and Firestone white line tires and raised letters tires were detailed.

[Dave S.]

Re: 1970 tire date codes

1970 and prior tires did not use a standard federal coding system. Prior to the federal system coming in each manufacturer had it's own system.

Scott,
Actually the 70 and earlier coding system was used into 1971 tire production. At one time it was thought the DOT mandated the federal (new) system on Jan. 1, 1971 but tires have been seen with the old coding syatem into mid 1971. Based on that I would assume that the new coding system was optional and eventually by mid 1971 the new system was fully used by at least Firestone and Goodyear.

[Scott G.]

Re: 1970 tire date codes

Thanks for clarifying the cutoff date. I wish the Tire Rack site would clarify their date code page. The description should read 1971 to 2000 instead of pre 2000. I have seen that site listed on other collector car sites as a reference to date original spare tires. Obviously it creates a lot of confusion when the code on an old tire does not match the system listed.

Scott,
Actually the 70 and earlier coding system was used into 1971 tire production. At one time it was thought the DOT mandated the federal (new) system on Jan. 1, 1971 but tires have been seen with the old coding syatem into mid 1971. Based on that I would assume that the new coding system was optional and eventually by mid 1971 the new system was fully used by at least Firestone and Goodyear.

[Terry M.]

Re: 1970 tire date codes

Thanks for clarifying the cutoff date. I wish the Tire Rack site would clarify their date code page. The description should read 1971 to 2000 instead of pre 2000. I have seen that site listed on other collector car sites as a reference to date original spare tires. Obviously it creates a lot of confusion when the code on an old tire does not match the system listed.

Very few people are interested in tires dated pre-1971 -- even in collector car circles. Tire Rack is interested in selling you new tires. Their customers (besides Patrick and I) are not interested in tires made before 1971, so they have no motivation to inform anyone of that data. I doubt it will do any good, but I will communicate the issue to my contact there next time I have occasion to talk with him.

I seem to recall seeing a site I found on a Google search once that had the text of the 1969 (yes, I think it was that early) DOT regulation proposing the "new" date code. There is or was the Canadian version of the "new" date code regulation at about the same time. I also recall seeing the industry objections regarding the labor involved to change all the molds. I can't now recall if it was on the RMA (Rubber Manufacturers Association) or a .gov site. I am relatively sure the Canadian material was on a .gov.cn site. There is or was a lot of information on the Internet about the change in 1971. I found it as I was looking for something suitable to print out about date codes for my automotive tech class about a decade ago.

[Scott G.]

Re: 1970 tire date codes

Terry, I undertand the Tire Rack is not in the business to supply collector car information. However, I have seen that chart refered to on several collector car sites. On an Oldsmobile site I frequent there was a discussion on 1970 442 original tires. I have also seen it referenced on a Buick forum. The Tire Rack site was referenced as a source for dating tires on both tires.

Very few people are interested in tires dated pre-1971 -- even in collector car circles. Tire Rack is interested in selling you new tires. Their customers (besides Patrick and I) are not interested in tires made before 1971, so they have no motivation to inform anyone of that data. I doubt it will do any good, but I will communicate the issue to my contact there next time I have occasion to talk with him.

I seem to recall seeing a site I found on a Google search once that had the text of the 1969 (yes, I think it was that early) DOT regulation proposing the "new" date code. There is or was the Canadian version of the "new" date code regulation at about the same time. I also recall seeing the industry objections regarding the labor involved to change all the molds. I can't now recall if it was on the RMA (Rubber Manufacturers Association) or a .gov site. I am relatively sure the Canadian material was on a .gov.cn site. There is or was a lot of information on the Internet about the change in 1971. I found it as I was looking for something suitable to print out about date codes for my automotive tech class about a decade ago.

[Terry M.]

Re: 1970 tire date codes

Tire Rack posts the information for their purposes. Other people take that information and use it for their purposes. How is anyone to know what use their posts will be put to? There is no way any of us can anticipate the way our words will be taken and used.