It’s easy to forget the importance of a car’s tires. As the sole point of contact, your vehicle has with the ground, tires should always be checked, refilled or replaced as often as needed to guarantee a smooth and safe ride.
But as a tire gets older, the likelihood of it developing a flaw or weakness grows exponentially. One such problem is tire dry rot, otherwise known as sidewall cracking. Left unnoticed, tire dry rot can lead to serious safety problems.
Tires naturally degrade over a period of time because they’re made from rubber. When a tire ages, it loses the protective resin which keeps the rubber from oxidizing and drying out. As those oils evaporate, the tire becomes brittle, and starts developing cracks and begins to break apart.
Tire dry rot is a condition that expedites the aging and drying process. It occurs when a tire encounters certain substances, temperatures or vulnerable situations. While it's easy to prevent, it can be difficult to repair when it begins to form.
There are a lot of factors that can contribute to dry rotted tires. Temperature, age, and exposure to sunlight all play a significant role in dry rot development. However, the most common reason for tire dry rot is also the easiest to avoid: prolonged periods of inactivity.
When a car is parked in one position and stationary for a long period of time, its tires begin to age and dry. This is because tires are engineered to be used frequently over many years. Resins in the tire compound are designed to protect the rubber, but only if it’s actively engaged and in motion.
The longer a vehicle sits unused, the more likely dry rot will develop. This is especially true if the tires are outside and exposed to fluctuating temperatures and direct sunlight. Climate has an immediate impact on the lifespan of a tire, and the National Highway Traffic Safety Administration (NHTSA) conducted research that suggests hot temperatures cause tires to age faster.
According to safercar.gov, “Exposure to high ambient temperatures can accelerate the tire aging process, which could contribute to tire failures, including tread separations.”
Fortunately, it’s not difficult to determine whether your tires are beginning to dry rot. Whereas a healthy tire is smooth and crack-free, a dry rotted tire tends to resemble cracked leather or elephant skin. These cracks can be large and noticeable or small and veiny, depending on the severity of the dry rot. Discolored rubber is a clear indication that dry rot has progressed to a more advanced stage.
Touching your tires will also reveal a change in texture. A tire with dry rot will feel brittle and rigid.
Severe cases of dry rot will have a noticeable effect on your driving. A front tire with dry rot will cause your steering wheel to wobble at low speeds, while dry rot on the rear tires will cause the whole car to wobble. This only occurs when the tread begins to separate from the tire itself—a situation that’s best avoided.
The short answer? No.
Cracks of any type should be repaired or replaced as soon as possible. The only time you should drive a car with dry rotted tires is while you’re heading to a mechanic or tire service shop. When a tire has dry rot, air can escape through cracks in the tire rubber easily. As a result, keeping a tire with dry rot inflated can be an endless struggle.
Over time, the cracks on a tire will grow deeper and longer in length. When a crack reaches the cords of a tire (the nylon and polyester yarns that are woven into tires to support vehicle weight), the heat of driving will expand the rubber. This causes the tire to break apart while driving.
You can reduce the factors that cause dry rot by taking a couple of preventive measures.
Purchase high-quality tires when replacing an old set of tires. According to Popular Mechanic, “Even if there are no signs of rot, the industry standard is to swap out tires before they hit 10 years old, and some tire companies recommend replacement as early as six years after manufacture.” When purchasing new tires, opt for high-quality over inexpensive tires and choose tires based on speed rating and treadwear strength.
Drive regularly and avoid letting a car sit unused for long periods of time. If you take an extended vacation and plan to leave your car idle while you're away, enlist a neighbor or friend to drive your car regularly to keep the tires active.
Avoid harsh environmental conditions. Most of us live in temperate zones, meaning our tires experience all four seasons. Hot and cold temperatures accelerate the aging process in tires, especially if the shifts in temperature come rapidly. If you happen to live somewhere with extreme summers or winters then it’s a good idea to check your tires often. Anyone familiar with colder climes knows that roads deteriorate quickly due to snow, ice, and fluctuating temperatures. The same holds true for your tires. Store your car in a climate-controlled garage to reduce the chances of dry rot.
Check air pressure once a month (or more). Underinflated tires can collapse and crease the sidewall of the tire. Older tires are more likely to crack, collapse or develop dry rot if driven while underinflated. According to a study by the NHTSA, 12% of all passenger vehicles in the U.S. have at least one underinflated tire.
In addition, protective tire sealants are also available. These not only restore the glossiness of a new tire but protect the tire from harmful UV rays that can lead to cracking and dry rot. Just be sure to use non-petroleum based products, as petroleum can actually destroy the weathering agents in the tire’s rubber.
Oils and lubricants can only go so far to keep your tires sturdy and reliable. When in doubt, contact a nearby tire specialist or consult your mechanic. They can determine whether the dry rot can be subdued or if it’s in your best interest to replace the tire altogether.