Portuguese 
Spanish 
If You Don’t Know What Those Colored Lines On New Tires Are For, This Article Is For You
It is common for drivers and motorcyclists to notice thin colored lines on the tread of new tires and wonder why those markings exist. These lines, often in vibrant colors like red, blue, or yellow, appear shortly after purchase and disappear after some time of use. But after all, why are they there?
What Are The Colored Lines For?
The colored lines on new tires are temporary markings applied during manufacturing. They have no function for the end consumer. Their main utility is within the factory, serving as visual identification and control codes during production.
These lines help in identifying components, controlling batches, organizing inventory, and guiding operators.
-
New York removed the tracks from over 2,500 subway cars and dumped everything at the bottom of the Atlantic, and what seemed like trash turned into an artificial reef teeming with fish and divers.
-
From matches sold by bicycle at age 5 to a global furniture empire: the lumberjack’s son founded IKEA at 17 in his uncle’s kitchen and transformed a small company into the largest furniture retailer on the planet.
-
The mansion in Flamengo, built in 1865 for the Baron of São Clemente and closed for 20 years, has become a spa, event hall, and gym for “Symphony,” a luxury condominium that sold 70% of its gross development value in the first month on the R$ 60 million land of the former Bennett College.
-
The Ipiranga convent, a 1924 building adjacent to the Museum that remained vacant for a decade and became home to dozens of cats, is reborn as “Alma Mater,” a luxury development worth R$ 130 million with a pool in the courtyard and a clubhouse in the former nuns’ chapel.
For example, while assembling a tire, different types of rubber and materials are used. The colors help identify the correct type of tread and ensure that everything is combined correctly.
Additionally, with large-scale production, these lines assist in separating and tracking batches, making inspection and internal organization easier. For machine operators, they also serve as visual guides during manual and automatic steps.
Each Manufacturer Has Its Own Code
There is no single standard for these markings. Each manufacturer uses its own internal system. Therefore, the same color may indicate different things across different brands. A blue line on one brand’s tire does not represent the same as a blue line on another’s.
These lines are designed to fade over time, usually after a few hundred kilometers. Once mounted on the vehicle, they are no longer useful.
How Are These Lines Applied In Production?
The colored lines are applied during the preparation phase of the tread, before the tire is fully assembled. This happens after the rubber compounds are mixed, when the tread is formed by extrusion and receives these markings.
After that, the tire still undergoes the assembly of other parts, such as fabrics, sidewalls, and beads, until it becomes what is known as a “green tire,” which has not yet been vulcanized. At this stage, the lines help confirm that the correct materials are being used.
Next, the tire is vulcanized. This means it is placed in a heated mold under pressure, where it acquires its final shape, strength, and the definitive markings on the sides, such as the size and brand name. Even after vulcanization, the colored lines remain visible but have no further function.
Demystifying The Myths About Colored Lines
Even though they are merely part of the production process, these lines generate doubts and even misconceptions among consumers. Some believe they indicate quality, balancing, or even the age of the tire. But these assumptions are incorrect.
There is no relationship between the lines and the quality of the tire. They also do not indicate the balancing point, as some think.
For that, some tires have small marks on the sidewalls, usually in yellow or red, with a specific function during balancing. The lines on the tread do not serve this purpose.
Another common misconception is that they assist in assembly or alignment. Asymmetrical or directional tires have markings on the sidewalls, such as “OUTSIDE” or arrows, indicating how they should be installed. Alignment is performed on the car and has no connection to these colored lines.
Even the idea that they indicate a newer tire is wrong. The true manufacturing indicator is the DOT code, located on the side of the tire, which shows the week and year it was produced.
What Really Matters When Buying
For those looking to buy or evaluate a tire, there are other pieces of information that are much more important than the colored lines. See what they are:
- DOT Code: Informs the origin and date of manufacture.
- Measurements: Width, profile, and rim diameter (ex: 195/60 R15).
- Load And Speed Ratings: Show how much weight the tire can support and the maximum speed it is designed for.
- UTQG: A standard used in the U.S. indicating wear, traction, and heat resistance.
- TWI: Small projections in the tire tread showing the legal wear limit.
- Mounting Marking: Such as “OUTSIDE” or arrows for tires that require specific mounting.
These pieces of information ensure the safety, performance, and compatibility of the tire with the vehicle.
Conclusion
The colored lines on tires are just part of the manufacturing process. They help organize, identify, and control materials within the factory but have no direct effect for the consumer.
Even though they catch attention at first glance, their presence or absence indicates nothing relevant for those using the tire.
When choosing a tire, it is best to look at the technical data, check the DOT code, and follow the manufacturer’s recommendations.
The colored lines are just a passing detail—a vestige of the care and complexity behind the production of an essential item for safety on the roads.
With information from Diário do Litoral.
