Know Your Tire DNA

You can tell a lot of information about a tire just by looking at it. Whether you’re looking at the tire label on the sale of a new tire or the DOT number molded onto a tire’s sidewall, it’s important to be able to read and understand this information so that you can provide the best service possible for your customers.

Reading Tire Labels and Markings

The first step in understanding a tire is knowing how to read the various brandings and labels on the tire. These labels provide you with the size specifications and replacement information you will need when a new customer comes in with a problem. Tire Registration Plus has built-in intelligence to safeguard against making mistakes when entering tire information from tires with difficult-to-read labels.

Tire TIN and DOT Markings

All tires are marked with a TIN (Tire Identification Number) or DOT code on the sidewall. This number includes basic information about the tire’s construction, capacity and characteristics. The DOT code is listed in full on only one side of the tire, with a partial DOT listed on the accompanying side. Tires made before the year 2000 and tires made after 2000 are marked using different formats. This can be confusing to technicians. Remember, federal law requires the full DOT number to be listed on only one of the sidewalls.

Reading Tire Date Codes

The DOT code contains a unique character code that gives a lot of information about a tire, including:

  • Week and year of production
  • Place of production
  • Size of the tire
  • Manufacturers exclusive code

An example DOT code would look something like this: DOT PJ41 30HV 1021

  • The last four digits in this example (1021) state the week and year of production, but not a specific day.
  • The last three numbers are 021 – the first two (02) means a production date in the second week of the year.
  • The last number (1) means a date in the first year of the decade.

Tire Size Label

One of the more important aspects of a tire label is the tire size specifications. Typically, you will find a number similar to the following: 255 / 45 R 17 93W

  • 255 – Tire width at its widest point
  • 45 – Aspect ratio(profile) – % of tire width
  • R – Construction type – R (Radial), D (Bias-ply), B (Belted)
  • 17 – Wheel size it fits(inches) - Often proceeded by a code to denote the type of tire:
    • P (p-metric)
    • LT (light-truck)
    • T (temporary spare)
    • F (run-flat)
    • Z (Z rated)
  • 93W – Service description:
    • The number (93 in this case) indicates the max load the tires are rated to carry
    • The letter (W in this case) indicates the max speed the tire is rated for. This includes L, M, N, P, Q, R, S, T, U, V, H, V, W, Y, (Y) – Speed ratings range between 75-186mph

Changes in Tire Labels

Tires made before the year 2000 were labeled and marked very differently than the majority of tires on the road today. Some tires were imprinted with a small triangle after the DOT code to signify a production date in the 1990s. NHTSA has indicated that new standards for DOT and TIN labeling requirements are set to hit in the mid 2020s.