What do car tyre numbers mean? Most often times I have wondered the meanings of the various numbers and letters that are usually scripted on the side of tyres. I know a lot of you also wonder about it. I did a little research and will explain what they mean.
The numbers on car tyre are explained using the letters and numbers printed on the side of the tyre. They tell you the tyres purpose, the complete dimensions, the total load/weight capacity, speed rating and more. They indicate what we call the Tyre code.
The code includes the tyre size, radial construction, the type of vehicle the tyre was made for, speed rating, and PSI inflation rating which indicates the amount of air that should be blown into it. Tyre specs also include something called load rating. This is important for hauling or towing a trailer. Read below for a complete tyre guide.
Car Tyre Numbers Meaning Explained
Tyres will have something similar like this printed on the side of it: P205/60R16 90H
The first letter means type of tyre for certain vehicles.
P = Passenger vehicles tyre
T = Truck vehicles tyre
The 3 digit number (185) is the Width. This number refers to the tyre width in millimeters. It is measured in millimeters from sidewall to sidewall.
The 2 digit number (75) is the Aspect Ratio. It is the ratio of the height of the tyre’s cross-section to its width. The number 75 means the height is equal to 75% of the width of the tyre.
The letter (R) stands for Radial. This means the layers run radially across the tyre.
The number (14) is Wheel Diameter. It is the size of the wheel measured from one end to the other. It tells you the size of the wheel (or rim) that the tyre is intended to fit on.
The next number (82) is the Load Index. Load Index shows the maximum load that the tyre can support when inflated properly. You can also find the maximum load on the tyre sidewall in both LBS pounds and KG kilograms.
The last letter (S) identifies the Speed Rating. The speed rating tells you the maximum speed capability of a tyre. A tyre with an S speed rating has a maximum speed capability of 180 kmph.
How to determine your tyre speed rating
Here is a chart that will identify your tyre speed rating. The last letter on your tyre will be one of the letters below:
M = 130 kmph
N =140 kmph = Spare Tyres
P = 150 kmph
Q = 160 kmph = Winter Tyres
R = 170 kmph = Truck Tyres
S = 180 kmph = Cars and Minivans
T = 190 kmph = Cars and Minivans
U = 200 kmph = Sport Performance Cars
V = 240 kmph = High Performance Cars
W = 270 kmph = Ultra High-Performance Cars
Y = 300 kmph = Ultra High-Performance Cars
Coming Soon: How To Determine A Tyre’s Expiry Date
I hope you find this piece useful, buying the right tyre for your vehicles can ensure safety on our roads.