Not only the safety of the driver and passengers, but also the durability of the tires themselves, depends on the correct selection of tires. But how do you decipher all these designations that are written on the tires in order to choose exactly what you need?
Instructions
Step 1
When choosing tires for a car, be guided by their standard size. It can be found and read on the side of the tire. Typically, the standard size is applied in large characters and has the following form 255/50 R17 85H. The first number 255 denotes the width of the tire profile, indicated in millimeters.
Step 2
The number 50 indicates the height of the tire's cross-section. It is usually indicated as a percentage of the width of the tire. In our example, the tire height is 50% of its width, which is 255 mm. Armed with a calculator, it is easy to calculate that the tire height will be equal to 127.5 mm.
Step 3
The profile height is often referred to as a series. You can find tire sizes where the series is missing. These tires are called full-profile tires. If you calculate the ratio of height to width, you will find that on about all full-profile tires it will be 80% or 82%.
Step 4
The designation R17 is used to encrypt the radius of the tire. It is denoted by a capital letter R, which indicates that the tire is a radial type tire. Following the letter R is the wheel rim diameter in inches that you can fit the tire to. In our case, the tire diameter is 17 inches.
Step 5
The number 85 indicates the maximum permissible load that the tire can withstand and is called the load factor. Each figure corresponds to a certain load indicated in special tables in kg. In this case, the index 85 corresponds to a maximum load of 515 kg. Despite the fact that this indicator can be considered conditional, do not neglect it when choosing tires. You can also often find the decoding of the load on the tire itself after the Max Load inscription in the form of two numbers, the first of which is indicated in kg, and the second in pounds.
Step 6
The H designation is the speed index. The indicator characterizes the maximum permissible speed at which the manufacturer guarantees the preservation of the declared performance characteristics of the tire. The H index corresponds to a maximum maximum speed of 210 km / h. On all tires, in addition to the standard size, its manufacturer and model are indicated.
