You just bought a new set of tyres for your drive and notice some strange markings when installing them. These are strange red and yellow dots. All at random places on the tyres’ sidewall, not all tyres have them and some only have one of the two. You are confused and worried if you brought the right tyres or if you’ve been scammed.
Worry not, there’s nothing suspicious about these red and yellow dots on the car tyres. To explain in one line: These marks help technicians fit the tyres on the wheels with proper balancing without requiring external weights or very minimal weights.
Unsure of what that meant? Read along, and by the end of this blog, you will know what these Red and Yellow dots are.
Tyres are not perfect
Tyres, unlike many other vehicle components, are not made up of a single material. A tyre comprises a carcass layer, steel belting threads, sidewalls and sealing layers that are put together on a production line.
At times, there are deformities left inside the tyre which means the tyre does not have the same weight, mass, dimensions and rigidity, at all places. To correct this, manufacturers analyze the tyre and mark them with red and yellow dots. These signify different meanings.
Yellow dots on your tyre
Yellow dots on your tyre mark the place where the tyre weighs the least. There can be many reasons why the tyre weighs less at that spot. It can be because of the inconsistency of the rubber, some imperfection or raised branding on the side. For this reason, your tyre is lighter than any other point in your tyre.
Red dots on your new tyre
Red dots on your tyre mark the highest point on your tyre.
Isn’t my tyre supposed to be a perfect circle?
It is, but tyres are not perfect circles.
Often, tyres will have a deformity raising that point, a little bit above the rest. It will appear as a slight bulge on the edge. Sometimes it will not be visible to the naked eye, but machines can identify these spots.
Yellow dots tell about the weight distribution while Red dots tell you about the roundness of the tyre.
Yellow and Red dots. How do I use them?
Your wheels (rims) aren’t perfect either. We use the imbalances of the tyre and the wheel to our advantage for proper wheel balancing.
Yellow dots represent the lightest spot on the tyre. Aligning the lightest part of the tyre to the heaviest part of the wheel means that the tyre/wheel balance is as close to being optimal as possible. External weights are put into place if it is still way off-balanced. Fewer weights mean a quieter, more comfortable ride, and a longer tyre life.
Red dots represent the highest point on the tyre. Red dots are aligned to the lowest part of the tyre (usually marked with a white mark or a drilled circle) for proper alignment. By doing so we reduce the vibrations caused by the high point of the tyre.
RED OVER YELLOW ALWAYS
In case your tyre has both red and yellow dots and you have no markings on the wheel, then the red dot always precedes the yellow dot. Align the red dot to the valve stem and viola, you have a well-balanced tyre.
In case you still experience vibrations, inside the car, your wheels need to be balanced and seeking professional help will be recommended.
Only Yellow Dots
What if your tyre has a yellow dot alone with no red dots? And your wheel does not have a marking also? In such a situation, align the yellow dot with the valve stem. It will ensure proper wheel balancing with minimal vibrations. Do this regardless of steel or alloy wheels.
Conclusion
It is important that your tyres are well-balanced and deliver the best performance possible. A well-balanced wheel/tyre will reduce vibrations and provide better comfort, reduce cabin noise, prevent accidents and increase the life of the tyre. Hence, manufacturers provide these red and yellow dots on tyres for the ease of the customer or the technician who will install them.
Over time, these spots will disappear by the wear and tear of the tyre. It is difficult to identify the highest point (red dot) and the lightest part (yellow dot). In this situation, you will have to get it fixed by professionals who will use specialized machines to identify and match these spots.