What do tyre size numbers mean?
Your tyre’s sidewall contains all the data about your tyre in the form of numbers and alphabets. Read to find out what they indicate.
Your tyre’s sidewall contains all the data about your tyre. There are a series of numbers and alphabets on the sidewall. These numbers represent the size, the load bearing capacity and speed limit of your tyre. Understanding these code words will help you choose the perfect set of tyres for yourself, according to the demand of your vehicle and your driving style.
For example, your tyre sidewall marking says, 195/55 16 R 87V, you can read it as:
195 – Section Width – It is the tyre width in mm. It is measurement of the sidewalls of a tyre that starts from the surface where it connects with the rim to the part where the tread begins.
55 – Aspect Ratio – It is the height of the sidewall expressed as a percentage of the tread width. Here, an aspect ratio of 55 indicates that the section height of the tyre is 55% of the section width of the tyre.
R – Construction – R represents the Radial contruction of the tyre. You will also find the letter B written on several tyres that represents the cross ply construction type. However, radial tyres are the most popular ones.
16 – Rim Diameter – It is the inside diameter of the tyre. It indicates the diameter of the rim or rim height and is measured in inches.
87 – Load Index – It is the maximum weight limit that a tyre can carry. It is represented by a two digit or three digit numbers. For example, if the load index given on the tyre is 95, then it depicts that the tyre is capable of carrying a maximum load of 690 kg. This conversion from load index to load in kg is determined by look-up table.
V – Speed Rating – It is the maximum speed that the car can maintain with the given tyres and is denoted by English Alphabets. For example, if a tyre has got a “S” rating then it can reach a maximum speed of 180 km/h.As with the load index.
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