Check Your Tires!

[Bill_VA]

I just read the exploits of another forum member that bent up his car pretty well driving on cold, old tires.

If your tires are older than 6 years old, you'll want to seriously consider replacing them. Rubber doesn't last forever, and tires are subject to drying and rotting over time, and you may not even notice it or even be able to detect it. Isn't the safety of you and your passengers worth the cost of a set of tires?

When I first built my car I bought some crappy Sumitomo's, but I didn't know they were so crappy until I got something better. I learned to drive my Cobra with lesson-than-optimal grip, so when I did get better tires I was able to always (knocking on wood) keep the car between the ditches. Back then I upgraded to Kumho Ecsta XS's, but they stopped making them in the 315 width. Now I run the Nitto NT05's and they're awesome - you just need to be much more judicial in the application of the gas pedal when the temps fall below 50.

Wade Chamberlain (God, rest his soul) once gave me advice on tire pressures. He said 1 PSI for each 100lbs the car weighs, so I run my tires at 25 PSI.

[GoDadGo]

Bill,

I'll be replacing my tires in the spring.
I've been looking for a while.
Thanks for posting this.

Steve

[D Stand]

Thanks for posting. I too will be replacing my Sumitomo’s before the next season. They came with the FR500 wheels that I bought to just roll around the shop. They do not look bad on the car, but the tires are old..

[Ted G]

This is good info and regarding the cold tires; yes, be very judicial on the gas pedal. I am running Toyo R888 and they are slippery when cold. I am pretty sure that I will wear out my tires before they ever get too old. 5 months of driving since my completion date and I hit 2600 miles as of yesterday!!

[Pmieras]

Tires also have a date code on them which is good to check when you are purchasing new / replacement tires. Who knows, maybe they sat on a shelf for a long time before they were sold.

[Pmieras]

TIN=Tire Identification Number

7-12 Character TIN
The first two characters will be a code that represents the assigned plant code for the manufacturer.
The next one to two characters represent the tire size code.
The next grouping can be no more than four characters that are designated by the manufacturer with their internal codes for the specific construction of that tire. Because these characters are optional for the manufacturer, the TIN can be any length up to a maximum of twelve characters.
The final four digits, for any tire made since the year 2000, are the tire date code and represent the date of manufacture. The first two of these digits designates the week of the year the tires were made, and the final two digits are the last two digits of the year of manufacture. (For example, 1319 means the thirteenth week of 2019.)

13 Character TIN
The first grouping consists of three characters that represent the plant code. Recent legislation is transitioning the factory code from two to three characters. This additional digit is what will push the DOT code to be 13 characters in total length.
The second grouping consists of six characters that identify the tire size, tire type, or other significant characteristics of the tire; unlike the eight to twelve-character TIN, these characters are not manufacturer optional.
The last four numbers represent the manufacturer's date. The first two numbers indicate the week, while the last two indicate the year. (For example, a tire with the number 2910 was manufactured in the 29th week of 2010.)
The full DOT code (including the date code portion) is displayed on at least one sidewall of every tire. The opposite sidewall – will have either a full DOT code (including date) or a partial DOT code (without the date code and any optional characters) at the manufacturers’ discretion.

If your tires were made before the year 2000, the date code will be only 3 digits – the first two digits again listing the week of the year, and the last digit being the last digit of the year of the tire’s manufacture. This means a date code of “529” could mean the tire was manufactured in December 1999, or December 1989 – or even December 1979.

Special note: All tires manufactured after April 13, 2025, must comply with the thirteen-character TIN requirement.