How to Read Car Tire Codes and Sizes

How to Read Car Tire Codes and Sizes - Tires are components of motorized vehicles (2 wheels or 4 wheels) that have a special function and are very important in driving. To obtain optimal function from tires, of course we need to know things that can reduce tire performance. The easiest way is to read the code and tire size.

On the side wall of car tires there are several identification codes regarding tire size, capacity, year of manufacture, tire pressure and brand. Maybe for vehicle owners, it is familiar to see these codes, both in the form of numbers and letters. However, many vehicle owners do not know what the code on the side wall of the tire actually means. Ok, in this article, we will discuss how to read the car tire code, so that vehicle owners don't get the wrong size if they want to replace tires with new ones.

Since there are several codes, let's start with the tire size code first, so how do I read the tire size code?

How to Read Car Tire Size Code

As explained above this code is printed on the side wall, this code informs about several things such as size, construction, year of production, wheel size, maximum load, and rotation speed.

In the picture above, the tire size is written with the tire code 205/55R16_91V. To read the tire size code, you can follow the following guide:

1. Three numbers in front as the tire width code

In the example above there is a tire code (205/55R16_91V) with 3 digits in front of 205. This means that the tread width of the tire is 205 millimeters when the tire is attached to the wheel.

2. The two numbers after the slash are the tire ratio

In the example tire code (205/55R16_91V). The two numbers after the slash are 65. Now this is the code for the tire ratio. What is tire ratio? So in short the tire ratio is the percentage of the tire height to its thickness.

3. The letter after the ratio is the tire construction code

In the example tire code (205/55R16_91V). One letter after the ratio, namely R is the tire construction, which means this tire is included in the Radial tire type.

4. The two numbers after the letter are the wheel diameter code

In the example tire code (205/55R16_91V). The two numbers after the letter are 16. Now 16 is the diameter of the wheels, so these tires are attached to 16-inch diameter wheels.

5. The last two numbers are the load index code

In the example tire code (205/55R16_91V). The last two digits are 91. This code is the code for the maximum load the tire can withstand.

Here is a list of tire index load codes that you need to know to be able to read tire codes

Load Index:

• 66 is the code for a maximum load of 300 Kg
• 68 is the code for a maximum load of 315 Kg
• 70 is the code for a maximum load of 335 Kg
• 73 is the code for a maximum load of 365 Kg
• 75 is the code for a maximum load of 387 Kg
• 80 -89 is the code for a maximum load of 450 - 580 Kg
• 90 - 100 is a code for a maximum load of 600 - 800 Kg

Based on the load index code above, car tires with code (205/55R16_91V) have a maximum load-bearing strength limit of approximately 600 Kg with code 91.

6. The last letter is the tire speed code

In the example tire code (205/55R16_91V). The last letter is V. This code is the code for the speed rating that the tire can withstand.

Here is a list of tire speed limit codes that you need to know to be able to read tire codes

Tire Speed ​​Code:

• Q is the code for a maximum speed of 160 km/h
• S is the code for a maximum speed of 180 km/h
• T is the code for a maximum speed of 190 km/h
• U is the code for a maximum speed of 200 km/h
• H is the code for a maximum speed of 210 km/h
• V is the code for a maximum speed of 240 km/h
• W is the code for a maximum speed of 270 km/h
• Y is the code for a maximum speed of 300 km/h
• Z is the code for a maximum speed of 240 km/h

Based on the speed code above, a car tire with code (205/55R16_91V) has a maximum speed limit of 240 km/hour with code V.

How to Read Aspect Ratio?

Because most are still confused about the aspect ratio, so you must know in advance that the aspect ratio is the ratio between the height of the tire and the width of the tire (in percent)

Aspect ratio can be formulated:

Ratio = cross-sectional height / cross-sectional width x 100

Example of how to read tire code 205/55R16_91V

The tire code above provides information about the 205 mm tire width with an aspect ratio of 55, so here we don't know what the height of the tire is. To find the height, we just need to input the aspect ratio formula so that we get 205x55/100 = 112.75, then we can know that the tire code informs the tire size with a tread width of 205 mm and a tire height of 112.75 mm.

How to Read Tire Production Code

Like food products, tires also have an expiration date. Tires are made of rubber whose physical properties will change over time. The tire compound will harden and then cracks will occur on the surface and part of the tire wall. Hardening of the tires will reduce traction on the road and will cause discomfort when driving. So for you vehicle owners, you should learn how to read the following tire codes.

The expiry date of this tire is usually 3 years after the date of production or if we calculate the distance, the tire must be replaced after 60,000 km. By knowing the tire production code, we can determine how many years old our tires are.

The following is an example of the production code of a tire

In the picture above there is a tire production code 4020. To read the tire production code, you can follow the following guidelines:

The two numbers in front are the week code of manufacture

The last two digits are the year code of manufacture

In the example above there is a 4020 tire production. This means that the tire was produced in the 40th week of 2020.

Keep in mind that each tire manufacturer has a different type of coding, for example, if for example the code you see is X2001 it means that the tire was produced in the 20th week of 2001.

So a discussion about how to read the code and size of car tires. For motorcycle tires are also not much different, you can follow the guide above, hopefully this information is useful.