What do the yellow and red dots on car tires do?
When buying a new car, the owner easily sees yellow and red dots on the tires. Are they just for decoration or do they have any special function?
In addition to the black dots around the windshield, on new cars or cars that have just had their tires replaced, there are often yellow and red dots on the sidewalls and rims. Most people do not pay attention to this small detail, but according to car experts, it is the manufacturer's intention.
In fact, the yellow and red dots on the tires are to ensure the balance of the rim and tire during operation.
The materials used to make tires are rubber, synthetic fibers, steel fibers, and chemicals that help prevent wear and heat. Although the manufacturer has applied many technologies to optimize, each tire cannot avoid a certain error that we cannot detect with the naked eye. Therefore, after production, tires are checked and measured by specialized machines to determine the lightest position on the tire and a yellow dot is placed right there.
In addition, the heaviest point of the rim where the valve head is fixed to pump air into the tire is also marked in yellow. Rim manufacturers say that when mounting the tire on the rim, the mounting operation must be so that the symbol on the tire sidewall is aligned with the fixed position of the valve head on the rim to ensure the balance of the tire rim.
After a period of use, the yellow dots on the tire wall will gradually fade. At that time, repair technicians often use specialized machines and equipment to check. They will stick counterweights (lead pieces) on the rim if they detect an imbalance.
Not only are tires not uniform in weight, they are also not perfectly round. The manufacturer checks the point farthest from the center of the tire and marks it with a red dot. This is called the High Point of the tire.
Similarly, on the wheel rim there will also be a red marked point called the Low Spot - the point closest to the center of the wheel rim. The difference between this high point and low point is called the runout.
During assembly, to eliminate eccentricity on the tire rim, the manufacturer often aligns the high point on the tire with the low point on the rim (ie the two red dots on the rim and tire are aligned).
Nowadays, technology is increasingly advanced, helping tire manufacturers to create completely round tires and users rarely see red dot symbols on tire rims. Yellow dots still sometimes appear on popular car models.
