The little long rubber ends sticking out from the surface of new car tires are called "mold flash" or "rubber spurs." These rubber spurs are remnants of the manufacturing process and occur when the tire is being molded.
During the tire manufacturing process, the liquid rubber compound is poured into a mold, which is then heated and cured to form the final tire shape. The mold flash or rubber spurs are excess rubber that seeps out of the mold seams or gaps during this process. Once the tire is removed from the mold, these rubber spurs are trimmed off to create a smooth surface. However, sometimes small remnants may remain.
While these rubber spurs are generally harmless, they can create a minor cosmetic annoyance for some people. They can also create a small amount of extra noise or vibration when the tire is initially used. However, as the tire wears and the rubber spurs naturally wear down, they will eventually disappear.
It's worth noting that it's always a good idea to inspect your tires before driving and remove any loose debris or foreign objects that might be stuck in the tread, including any remaining rubber spurs.