# Finding the right car tire’s size

## Determine the size of the tire

The first approach, but also the safest, is made by comparing it with the size of the tire currently mounted on your car. However, it is important to pay attention to the right type of tire to avoid the dangers associated, for example, with driving summer tires in winter.

## Tire size in the vehicle registration information

The most important tire information can be found in the registration data of each car. It contains specifications such as the maximum load capacity and the maximum permissible speed at which the tires must correspond to be compatible with the vehicle in question. If necessary, the tire size indicated in the vehicle registration may be changed separately. This requires an inspection by an approved inspection body to ensure that the new tire sizes are perfectly adapted to the car. However, when you look at the vehicle registration warning, the size information is not always correct.

## What is the size of the tire?

The sidewall of your tire has an appearance that seems complicated at first glance. Below you will find the tire width, height/width ratio, manufacturer, rim diameter, load index and speed index in succession. But what are these parameters called, expressed in millimeters, inches and percentages?

The first data determines the width of the tire in millimeters. In this case, this tire has a width of 205 mm. The number 55 behind the slash indicates the tire’s height/width ratio in percent. This means that the height of the tires is 55% of their width – for the tire which would be 112.75 mm. This is followed by a letter that defines the type of tire. Usually it is an “R”. R means radial and means that the wires of the carcass are arranged radially under the tread. The second configuration would be diagonal but diagonal tires are rarely produced. The next number is the diameter of the tire. This number is expressed in inches, in this example 16 inches. Now you can know the different characteristics of the tires and their size on the rims you mount on your vehicle.

Tire sizes are followed by two other details, which provide information on the maximum permissible speed and maximum load capacity of the tire. Thus in the example, 91V, the load index 91 corresponds to a maximum load per tire of 615 kg and the speed index V to a maximum authorized speed of 240 km / h. The load starts at 30 (106 kg) and ends at 124 (1600 kg). In the speed index table, letters correspond to codes and vary from A to Y. For example, tires with the B identifier can only drive up to 50 km / h and the abbreviation Y corresponds to a maximum speed of 300 km / h.

Now you know how to know the size of your tires and what exactly the details mean. This will make it easier for you to buy tires for your car.