Installing the right tires is vital to enhance your vehicle’s performance and safety. As a car owner, you must understand which tire type suits your vehicle, especially when finding new tires. Meaning you have to know how to find and read your car tire. If you know your tire size and want new tires, get a quote from us. Learn how to find and read a tire size.

How to find your tire size

You can find the tire size for your personal or passenger vehicle in these places:

  • The tire sidewall of the current tire
  • On the door jamb sticker of the driver’s side door
  • Inside the glove box compartment
  • Within the petrol tank hatch

How to read tire size

Let’s interpret each letter/number on how they appear in the tire size data. Let’s use 976/60/R15 91S as an example.

The Letters P and LT

In most tires, you’ll find the letter P before the sequence: P976/60/R15 91S. P is a designation used by Tire and Rim Association for all passenger car tire types. It’s a P-metric tire meaning it should be explicitly used on passenger vehicles.

Sometimes you can find LT instead of P. LT in full is LT-metric, meaning light truck tires. The light truck tire types are designed for vehicles that pull heavy cargo or trailers. Conversely, T is for temporary, meaning suitable spare tire, while ST signifies special trailer.

Analysis of the sequence numbers and letters on the tire 

  1. Width is the first number/three digits appearing on the tire size information, always in millimetres. For example, 976/60/R15 91S, “976 “is the width from one sidewall to another.
  2. The aspect ratio, always in percentage, is the digits immediately after the first slash mark 976/60/R15 91S. Tire manufacturers find the aspect ratio by dividing the height of the rim size against its width. In this case, our tire’s height is 60% of its width.
  3. Construction is the letter that comes immediately after the second slash 976/60/R15 91S. It indicates the nature of the tire’s internal construction in maintaining stability. You can see two constructions: R- Radial and D- for Bias Ply or Diagonal. Radial construction means the internal ply cord of the tire is in a radial direction.
  4. Rim diameter is the diameter code of the rim in inches. Our rim diameter is 150inch diameter 976/60/R15 91S.
  5. The load index is the tire’s load index. It indicates how much weight (in kg) the tire supports if fully inflated. It’s a load index as it does not give the exact weight but corresponds to a load capacity listed in the index. 976/60/R15 91S. The numbers in the load index range between 60 and 179, representing carrying capacities of 250 kg to 7750 kg.
  6. Speed rating is indicated by the last letter and comes after the load index, 976/60/R15 91S. It corresponds to a specific speed capability based on a standard laboratory test. A tire with a speed rating of S is gauged up to 180 km/h, whereas a tire rated R is rated up to 170km.h

To find the right tire size to keep you and your family safe, contact TreadNation today.