C3-Tire date code

[Gregg Plapas]

I have come by a Firestone GR-7015 raised white letter tire with the "F" shield in raised white as well. I've been informed that the date code of the tire can be determined by the folowing numbers molded into the side wall. My numbers are as follows--FMJ183.In addition, the tire has several ink stamps on the tread (it has never been on the ground) they are-------U5FMO or a D and A511A. Anyone here know or can decode / transcribe the meaning of the above? Or point me to a web site to run the numbers myself? This is for a 1973 C3.

thanks,
Gregg

[Tom Freeman]

Re: C3-Tire date code

Gregg,
My understanding is that the last number, 3 in this case, is the year. So it could be a 73 tire. Could also be an 83 but don't think those were made then. The other numbers, I don't know.

tom...

[Gregg Plapas]

Re: C3-Tire date code

Tom, it's no 83, I can assure you of that. This is a 73 only tire, I am just glad I have it.

[Dave S.]

Re: C3-Tire date code

Gregg,
The last number is the year and the preceeding numbers are the week of the year. Thus 183 is the 18th week of 1973. It is 73 and not 83 as that style tire was not made in 83 or 93 as pointed out in the earlier post. They went to the long number in 1971 so I would expect your debossed number was longer than you posted.

[Gregg Plapas]

Re: C3-Tire date code

Dave,

The entire sequence goes as follows, VDU5 - FMJ183 - F15S.

The story is the guy wanted to see what type of spare he had been given after buying his 73 used. His keys did not work on the spare tire lock, so he drilled it out and out popped this diamond in the ruff. I just thought it would be good to know what the numbers actully mean for future reference. Now, if I only had 4 more just like it.:)

Thanks,
Gregg

[Dave S.]

Re: C3-Tire date code

Gregg,

The long dates I am familiar with have the week/year at the very "end" of the alpha numerical sequence. Yours seems to be somewhat different. I can't help with that but maybe someone more knowledgeable than I can chime in.

[Terry M.]

Re: C3-Tire date code *TL*

Prior to the year 2000, and beginning with the first week of calender year 1971, tire manufacturers were required by DOT to place a 10 character number on the tire sidewall. This is for DOT approved (road use) tires - non-DOT tires are another matter. The last three digits are as Dave described - in your case 18th week of 1973. There was no sure way to determine the decade, other than most tire models were/are not manufactured over a span of more than ten years. I have no idea what the F15S means, but it is not part of the DOT number.
Since the turn of the century the DOT number is 11 characters long and the date code is the last for digits. Thus we now have the decade in the date.
A google search of the internet will give you more information, and misinformation, on the DOT date code than you can absorb. I once found some real good information posted by the Canadian DOT, but a quick look tonight didn't turn it up. I wanted to post a link....

[Roger S.]

Re: C3-Tire date code

Per the 73-74 TIMJG page 54: & Richard Prince's Restoration Guide:
18 = eighteen week of year
3 = 1973 The Firestone 500's were not made after the mid 70's - remember the tread separation problems
U5 = GR70-15
The white triangle around the F was not used after June 1973.
FMJ is probably a Firestone designation for the tire construction method.
The complete TIN should start with a "V" to indicate Firestone.

When I worked for Kelly-Springfield the ink coding was placed on the tire components at its construction point. The component was then put on a rack or platform for transport to the storage area and then to the tire building machine. This enabled the worker to identify what each component was.

Roger

[Bob B.]

Re: C3-Tire date code

Only the 1973 Corvettes which came from the factory with Firestone 500's that were made with raised white letters, had the raised white "F" 1974 to 1977 the "F" was in black. I almost never see a 73 Firestone 500 tire anymore. Bob Beck

[Harmon C.]

Re: C3-Tire date code

I know where their is about 10 sets of 73 white shield 500,s . None for sale Lyle

[Steve lischynsky]

Re: C3-Tire date code

Why oh why would you guys want these tires (Firestone 500 from 1973)except to quickly swap them on for judging or add them on to a trailer queen.

Two of these tires split up the inside sidewalls within 1 year that I owned my 73. They split not while driving but sitting in a parking lot. Then there was some sort of recall by Firestone and a lot of bad press.

I got rid of mine because of safety issues.....I don't think you actually want to drive on them unless it's only on and off a trailer.

Steve L
73 coupe since new

[Tom Freeman]

Old Tires

Steve,
I agree with you. I would not drive on them just because of their age, let alone the bad history they had. They are strictly a judging field tire, not a road tire.

tom...




The '73 Spot

[Gregg Plapas]

Re: C3-Tire date code

YOU GOT IT! No one in their right mind would travel any distance with this type tire, strictly show field craziness! But, I think we here should try and preserve such original items such as this. After all, is this not what the NCRS is all about---restoration and preservation?

cheers
Gregg

[Steve lischynsky]

Re: C3-Tire date code

Maybe I should have kept those split original tires. I could have filled them with straw for judging.

Steve L
73 coupe since new