Why Car Tires Turn Brown – Tire Blooming Explained

Why Car Tires Turn Brown – Tire Blooming Explained

Updated on February 22 2024

You may have the cleanest and shiniest car in the neighborhood. But if the sidewalls of your car’s tires are turning brown, it ruins the look of an otherwise pristine-looking vehicle. Those brown stains are what auto detailers refer to as tire blooming. The word “blooming” may bring to mind flowers in the spring, but tire blooming is the exact opposite of picturing a warm, sunny day.

What is tire blooming, and what causes it?

Upon first glance, tire blooming may seem like accumulated dirt, mud, and brake dust on the tire sidewalls. However, you can have a set of clean and freshly washed tires and still experience tire blooming. The bad news is no amount of washing and scrubbing will rid the tires of those nasty brown stains.

Tire blooming is a chemical reaction that causes tire sidewalls to “grow” brown stains. The reason behind this strange occurrence is an organic compound called anti-ozonant. Anti-ozonant is an additive used in the production of rubber and plastic components. If the name is any indication, anti-ozonant protects rubber and plastic materials from fading, cracking, degradation, and oxidation due to repeated UV exposure.

Anti-ozonant is like sunscreen on your skin. Unfortunately, tire manufacturing utilizes multiple variants of anti-ozonant to make tires stronger and more resistant to UV damage and high temperatures. Without anti-ozonant, modern tires won’t last as long and will have a shorter lifespan.

In addition, ani-ozonant is present in the anti-stick chemicals applied to tire molds. Similar to Teflon in cookware, anti-ozonant prevents freshly-made tires from sticking to the molds. Furthermore, the non-stick chemicals will chemically bond to the tire, causing more anti-ozonant to accumulate and adhere to the tire surface.

But there’s a catch. Repeated and constant exposure to heat, air, moisture, and UV rays will accelerate the oxidation of anti-ozonants on the tire. And when this happens, tire blooming occurs.

Can tire black or tire dressing cause tire bloom?

You probably heard a rumor that tire black or certain tire dressings – whether water or silicone-based – will cause tire blooming, but nothing can be farther from the truth. On the contrary, regularly applying tire black or tire dressing will prevent the tire from “blooming” or growing those ugly brown stains.

Here’s the catch: Tire blooming occurs in the absence of proper cleaning, whether you use tire black or not. And it doesn’t matter if you have new or old tires. Neglecting to clean the tires will accelerate the occurrence of tire blooming.

How can I prevent and remove tire blooming?

Luckily for you, tire blooming is relatively easy to prevent and remove. Periodically washing and cleaning the wheels and tires is the single best and effective way to avoid tire blooming. Here are the easy steps so you can say goodbye to ugly tire blooms.

Step 1: Wash the wheels and tires every time you wash the car.

Admit it. Most of us wash the exterior without paying particular attention to the wheels and tires. Remember that the wheels and tires are among the dirtiest parts of your vehicle. After washing the car using water and car shampoo, you should clean the wheels and tires (before or after washing the car) using a different cleaning solution.

Whether your tires are blooming or not, using a few drops of dish soap (yes, Joy Ultra or Axion will suffice) mixed in a small bucket of clean water is more effective in hard-to-remove dirt and stains like mud and brake dust. However, do not use dish soap to wash the paint and windows unless you plan to wax or polish the vehicle afterward.

Grab a sponge or soft tire brush (or wheel cleaning brush), dip in the cleaning solution, and give the wheels and tires a thorough cleaning.

Tip: Dish soap or Joy Ultra will remove or dissolve the existing wax on your car’s paint. It will also dry out the rubber and plastic parts in the exterior of your vehicle. Never use dish soap to wash your vehicle.

Step 2: Rinse the tires thoroughly.

Grab a hose with running water and rinse off the suds thoroughly from the wheels and tires. Make sure to remove all traces of soap before drying the tires.

Step 3: Wipe dry using a clean cloth.

Wipe the tires dry using a microfiber cloth or terry cloth towel. If you’re dealing with a bad case of tire blooming, the tire sidewalls will still be brownish at this point, but don’t despair.

Step 4: Apply tire black or tire dressing.

Apply tire black or tire dressing on the tire sidewalls using a clean applicator pad or sponge. You don’t need to apply too much to achieve the best results. Give each tire a light coat, and you’re all good. If you don’t have tire black, you can use Armor All Protectant or a similar product.

Tire black is a chemical formula that restores the “black” look of the tire sidewall by revitalizing the rubber and leaving a nice, glossy shine. Water-based tire dressings are the preferred choice, although silicone or solvent-based tire black lasts longer and offers more extended protection against fading and UV damage.

Say Goodbye to Tire Blooming

Leaving the tires dirty with caked-on mud, dirt, and grime will accelerate the occurrence of tire blooming on the sidewalls. All it takes is regular cleaning and a nice coat of tire black to rid the tire of those ugly brown stains forever.