Why Is There a White Film on My Tires?

Everybody knows tires are black, round, and hold air, so it can come as a bit of a shock when brand new tires have a white, waxy film on the sidewalls and shoulder area. It doesn't wash off easily, and it "balls up" when you rub it with your finger. What is it? Why is it there? Sometimes it can be mistaken for scuffs from the shipping process, an unknown substance that was spilled on the tires, mounting lubricant, or even road salt during the winter months. It's actually none of these things, and if you handle enough tires, you'll find it's very common.

When tires are manufactured, after all the individual components are assembled, the completed, "green" tire is placed into a metal mold to be cured (technically, it's called "vulcanization," named after the Roman god of fire). The curing process involves intense heat and pressure over time, and afterward, the final, homogeneous tire is removed from the mold. Well, just like greasing the pan before baking a cake, lubricating the mold makes it a lot easier to get the tire out after the curing process. While each manufacturer, and sometimes even each plant, have different processes, it's possible the first few tires coming out of the mold may pick up some excess mold release agent. This mold release typically comes off the tire during the first 500 (or so) break-in miles after installation.

Additionally, tire manufacturers include additives in the rubber compounds that are designed to protect from sun, ozone, acid rain, age, and other environmental factors that try to break down the tire. These additives come in the form of oils, detergents, waxes, antioxidants, parabens, and more, and sometimes they can "bloom" to the surface of a new tire. While some may not like the appearance, we recommend not trying to clean it. In addition to being notoriously stubborn to remove, the white, waxy film on the tire is doing an important job by protecting the rubber and helping to prevent premature cracking. Typically, the excess on the surface will wear off with use, and the tire will present its natural, satin black finish while providing years of trouble-free service.