What Causes White Sidewall Tires To Scuff Or Discolor?

Using white rubber to add style to a tire's sidewall dates back into the early 1900s. In those days, the white rubber of wide, whitewall tires not only added style, but also acted as the sidewall's outer protective layer.

While most current tires feature black sidewall styling, selected luxury vehicle, performance car and light truck-oriented tires offer white stripe, raised white letter or outline white letter styling.

Today's white stripe and white letter tires feature a layer of special abrasion-resistant, non-staining black rubber on top of an underlying layer of white rubber all the way around the styled sidewall's circumference.

The tire mold is machined with recesses where the stripe/letter styling will appear. This allows both the black surface and underlying white rubber to be drawn up into the mold recesses as the tire is cured. After the tire has cooled, fine-grit grinding wheels carefully remove the top layer of black rubber from the raised portions of the molded design to reveal the white rubber below.

This construction method produces even white stripes and crisp white letters, as well as prevents oils in the black rubber compounds from migrating into the white rubber.

Since this condition is caused by adverse service conditions, the only corrective action is for the driver to take greater care not to rub the tire sidewall against curbs when parking. While unsightly, cosmetic sidewall scuffing doesn't reduce the strength of the tire. Some drivers will have their tires remounted inside out to hide the cosmetically damaged white sidewall under the vehicle. Drivers who repeatedly damage white sidewall tires may want to consider buying blackwall replacements when it's time to purchase new tires.

This tire condition is not covered by the manufacturer's materials and workmanship warranty and is not considered warrantable.

Discoloration

While oils are necessary ingredients in black rubber, their presence in white rubber will turn the rubber brown. Therefore, a special non-staining black rubber is used on white stripe/white letter tires to protect the white rubber by acting as a barrier that eliminates oil migration within the tire.

Shortly after tires have had their white stripe/letters revealed in the tire plant, the white sidewall side of the tire will be covered with a blue/green semitransparent protective solution that shields the white rubber while the tires are in storage, transit or being installed on the vehicle for the first time. Once the tires are installed, this protective coating can be washed away with warm water, regular soap and a fine-bristle tire brush.

Warnings: Harsh chemicals like brake cleaners, solvents or bleaches should not be used. In addition to the protective coating, they will remove some of the waxes and oils used to help the rubber compound resist aging and cracking.

High-pressure washers should be used sparingly on tires. Since concentrated high-pressure water spray can damage rubber, the spray wand should be kept at a distance of over 18 inches away from the tire to reduce the water pressure against the rubber.

Storage

Because white stripe and white letter tires only have non-staining rubber on their white sidewall side (standard blackwall rubber on the reverse side), they should always be stored white-to-white or black-to-black. If stacked, a set of four tires should be stored (from the bottom) white up - white down - white up - white down. This will prevent the black sidewall oils from transferring to and contaminating the adjacent white stripe/letters.

Since transfer of oils in blackwall tires is of no significance, it does not make a difference if they touch when stored.