Why do new tires have those tiny rubber spikes, that look like hairs, covering the entire tire? It's not for traction. They don't help silence road noise either. Nor do they help with gas mileage. So why are they there and what purpose do they serve?

According to YourMechanic.com those thousands of tiny rubber hairs on a new tire are called vent spews. They are made from air escaping the tire mold during the making of the tire.

When the tire mold is being filled with liquid rubber, as the rubber is being pushed into the mold using pressure, the air pockets behind the liquid rubber have to escape the mold. Thousands of tiny holes in the tire mold allow the air behind the liquid rubber to escape allowing the rubber to fill the mold completely.

The tiny rubber hairs on your new tires are literally rubber that's been pushed out of the tire mold like playdough. The rubber dries and since there is no need to trim the hairs off, tire manufacturers sell the tires with hairs intact. After a few miles, most will eventually wear off.

So, the only real purpose of those tiny rubber hairs on a tire after it's in your local tire shop or car dealership is to let you know the tire is new. In the factory, they allow trapped air to escape the tire mold, but when you see them, about the only message they send is that they are indeed new tires and are not used.

If you happen to come across "new" tires without those tiny hairs, ask a service representative to explain to you why the hairs are missing. It could be that some brands may trim them off or use a different manufacturing process that doesn't create those tiny hairs. The tiny rubber hairs allow you to rest assured that you are the first owner of your new wheels.

How It's Made—Car Tires

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