Updated On: 21 July 2021 Jatin Jhamb
There must have been several instances where you check out your desired car and when the spec sheets for the tyres are out, all you can think of is that these are 14/15/16/17 inches or more. Only some of them have an idea of what the numbers on the sidewall mean. In this article, we decode the numbers written on the tyre and explain the meaning in a simpler manner.
Let's take this image as an example and explain it to you -
Now, there are different types of tyres and we segregate them in terms of tyre class.
As you see in the image above, the first letter is P. So that suggests this tyre belongs to a passenger car. Now, be it hatchbacks, sedans, SUVs, minivans or private pickup trucks. This type of tyre is used here.
We also have LT that means lighter truck along with ST that means special trailer. They carry heavier loads and generally have less sidewall.
This is basically the distance between the inner and the outer sidewall. In layman terms, this number is written just after the tyre type. In the image given above, the tyre width is 205 mm. It is always measured in millimetres.
In complex terms, this is known as the aspect ratio of the tyre. The aspect ratio number is generally calculated from the rim to the tread. From the image above, it says, P 205/55. Here, 205 mm means the width of the tyre and 55 is the overall height in percentage. The aspect ratio is always measured in percentage value.
If you see a higher number then that hints at a higher sidewall height and vice versa. Most of the race cars carry low profile tyres to have the maximum steering feedback while other passenger cars or the vans will have tyres with higher sidewall. The latter helps in a comfortable ride.
The alphabet R just after the tyre profile represents the construction type of the tyre. R stands for radial tyres and it is set as per the industry standards. They are durable tyres that offer lower rolling resistance and better mileage.
The numeric digit that comes right after the construction type means the wheel diameter. This number indicates that a particular tyre should be mounted on a 16-inch rim. Similarly, numeric digits 14,15,17,18 and more represent other things.
This indicates the load index and represents the amount of weight the tyres can carry when it is inflated at a maximum level. Below is the chart that will help in understanding more of this -
This is basically the speed index and is measured right from F to (Y). This is the maximum safe speed a tyre can travel when fully loaded. Below is the chart that will help in understanding more of this -
So have we made your tyre shopping easier or not? We hope that now you can identify what those numbers on the tyre mean. Also, make sure you are a member of our 91Wheels Whatsapp group and 91Wheels Telegram group. Here, we bring you all the latest updates related to the Indian Automotive Industry and you meet like-minded people.
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