Cracked Tires: Causes and Precautions

In today's fast-paced world, the modern car buyer is increasingly focused on the safety features and ratings of their potential new vehicle. Organizations like IIHS and NHTSA have made tremendous strides in improving road safety by rigorously crash testing and rating every new car that hits the market. However, an often overlooked but equally important factor that significantly contributes to road safety is the condition of a vehicle's tires.

Surprisingly, tire safety rarely occupies the same level of attention among buyers as other aspects of their vehicles. Rather than prioritizing the safest and most reliable tires, many opt for a more budget-friendly set, unwittingly compromising the performance and safety of their vehicle.

A more alarming trend is the tendency of vehicle owners to delay replacing their worn-out tires until serious issues arise, such as a complete loss of tread depth, tire bulges, visible wires, or cracks.

These tire-related issues not only pose a threat to the safety of individual drivers but also impact overall road safety. Among these concerns, cracked tires are particularly prevalent and often raise questions about their potential dangers. Unfortunately, there is no one-size-fits-all answer, as the severity of the issue varies from case to case.

To help shed light on this critical topic, I have prepared a comprehensive guide that delves into the world of cracked tires, exploring the causes, consequences, and possible remedies.

So, buckle up and join me on this enlightening journey to better understand the importance of tire safety and the role it plays in ensuring a secure driving experience for all.

What Leads to Cracked Tires?

Cracking can appear from numerous factors, each leading to changes in the rubber compound. However, cracked tires are most often caused by a combination of several factors. Here are the most common:

1. Age (old tires)

Tires lose their elasticity with time, and there is nothing you can do about it. Notably, this is called dry rot since it resembles rotting in wood or other organic materials. Dry rot makes the rubber compound brittle and reduces its flexibility, which compromises the structural integrity of the material. As a result, small cracks can appear on the surface of the rubber, becoming bigger over time.

Due to this, I highly recommend keeping your tires for up to eight years. After that, even if there is enough tread depth left on your tires, you should replace them with a new set, as the cracking would probably be severe.

Old and cracked tires can't provide you with enough grip, as the rubber compound becomes brittle and loses its road-sticking properties. That's especially true in rainy conditions, where cracked tires would just slide around, even at lower speeds. However, cracked tires can also lead to a sudden loss of pressure and, even worse, a blowout!

2. Sun exposure (harmful UV radiation)

Sun exposure, and especially the harmful UV radiation it produces, can accelerate the dry rotting of the rubber compound. In other words, if you leave your vehicle in the sun more often, the tires will age faster.

Trailer owners know this very well and cover the tires with cardboard or special screens to protect tires from harmful UV radiation. Notably, trailer tires suffer from dry rotting more than they suffer from the worn-out tread.

Obviously, keeping your car in the garage will greatly reduce the dry rotting, but you can also mitigate the issue by covering your tires. Or, use a full vehicle exterior cover, which will protect your tires from UV exposure, but also the paint of your car.

3. Ozone exposure

Ozone (O3) is a naturally occurring gas in the Earth's atmosphere. It usually resides at higher elevations, where it breaks down UV radiation before it enters the Earth. Thus, it protects us from harmful radiation. Still, ozone can be found on the ground as well, though in smaller quantities.

However, ozone is a highly reactive gas and can form molecules with just about everything. It's actually more reactive than the diatomic oxygen (O2) we breathe since it can donate one of the oxygen atoms, which leads to oxidation. And when it reacts with rubber, it can chemically react with the structure and greatly accelerate dry rot, also causing cracked rubber.

You could use some air quality smartphone apps to follow the ozone quantity in your area. This can be helpful because ozone is also bad for your health, as it can cause respiratory diseases.

Ozone is mostly present in urban areas due to human activities, such as releasing nitrogen oxides (NOx), which react with the sun's rays to produce ozone. Hot summer weather can also accelerate ozone production.

Unfortunately, there is no way to protect your tires from ozone.

4. Low inflation pressure

Underinflated tires can greatly reduce the stability of your car and make them less safe. However, underinflation can also lead to other issues, like damage to the tire's internal components (belts and plies), tread separation, bulges, and cracked rubber compounds.

The reason for this is pretty straightforward – the pressurized air inside the tire carries most of the vehicle's load. And when there is not enough of it inside the tire, all other components will be subjected to a higher load, which leads to accelerated wear, including cracked rubber.

Therefore, it's crucial that you check your tire's pressure at least once every month or more often if there is a sudden temperature drop, as that will also lower the pressure inside the tire.

5. Improper storage

If you use a combination of summer and winter tires, you should store the tire set that you are not using in cool, dry, and dark places, like your garage. Storing your tires improperly can accelerate dry rotting, which leads to cracked rubber.

6. Big temperature changes (harsh climates)

When the temperature changes, the rubber compound goes through several different phases and changes in its structure. In freezing weather, the rubber would become hard and brittle, while in hot conditions, it would be very elastic.

Thus, big temperature changes, especially if they happen fast, can greatly reduce the lifespan of your tires and introduce cracking.

7. Overloading the tires

Overloading the tires will put a lot of strain on the internal components, like the belts and plies, but also introduce more load on the tread and sidewalls, causing cracking on the rubber compound.

Therefore, it's crucial to estimate how much cargo you put in the trunk and the weight of the passengers, particularly if you stuffed your car to the teeth.

Automakers put OEM tires with a high enough load range, so make sure the new ones you buy have at least the load range of the original tires or higher. Also, follow the automaker's recommendations for proper inflation when the vehicle is loaded. Usually, you should inflate your tires to a higher psi when the vehicle is loaded.

Apart from cracked tires, overloading can also greatly reduce the performance of your tire, leading to worse handling and braking performance.

8. Using harsh cleaning chemicals

Petroleum-based chemicals that are found in many tire cleaners can cause dry rot and cracking. Thus, it's best practice to use regular soap for cleaning the tires while ensuring that it doesn't contain petroleum.

9. Poor puncture repairs

Punctures inevitably make changes to the internal structure of the tire as they pierce through the belts and plies. Therefore, punctures larger than ¼ inches (6 mm) are generally considered irreparable.

But regardless of that, many drivers and even tire technicians are happy to patch larger punctures. And, sure, the tire might keep pressure, but that's not the reason why repairing wide punctures isn't recommended – it's because the structure of the tire will be compromised. When that happens, several issues can appear, including tread separation, bulges, and cracked tires.

10. Leaving the tires stationary for long periods

Tires are designed to be driven, and leaving them stationary for long periods can cause flat spots and change the round shape of the tire. As a result, the rubber could crack in some spots. Therefore, even if you don't need your car, you should run it for at least a few miles every week to minimize cracking.

Is There a Difference Between Sidewall Cracking and Tread Cracking?

Yes, there is a difference between cracks on the tread and the sidewall, as both have distinct safety implications.

Tread cracking occurs on the part of the tire that comes into contact with the ground. It is usually caused by old age, but underinflation, overloading, and abrasive roads can also cause cracking. Tires with a cracked tread will provide you with lower traction, especially on wet and snowy roads. That's because cracked rubber is more brittle, almost like plastic, which lowers its ability to stick to the road's surface.

Meanwhile, sidewall cracking occurs on the side of the tire, i.e., the part that isn't in contact with the road. It usually happens due to aged tires, but also UV and ozone exposure, harsh chemicals, and big temperature changes. Unlike tread cracking, sidewall cracking doesn't have an impact on traction. However, it could lead to a sudden blowout or sidewall bulges.

So, all things considered, tread cracking and sidewall cracking are equally dangerous, even though they act differently. Therefore, if you notice cracking, it's crucial to consult a tire technician to determine whether it's safe to continue driving.

Are Cracked Tires Safe?

Generally, cracked tires are not considered safe. This is because they can lead to various hazardous situations, like a loss of traction on wet roads or a sudden blowout.

Still, it depends on the severity of the cracks. If they are really small, you could continue to use the tires for a few more months before replacing them with a new set, but make sure you first ask an experienced tire technician. Larger cracks are a no-go, meaning you should immediately seek to replace the tires.

How to Minimize Tire Cracking?

Taking care of your tires will ensure that cracking won't appear quickly and that they will last for at least eight years before you need to replace them with a new set.

Here is everything you can do to minimize tire cracking:

• Always maintain proper tire pressure. I recommend checking the tire pressure at least every month or more often if there is a sudden temperature change. You can find the correct tire pressure for your car in the owner's manual or the placard located on the driver's side door jamb.
• Rotate your tires regularly. I recommend a tire rotation every 5,000 to 8,000 miles or at each oil change for convenience. Tire rotation ensures even wear and minimizes cracking.
• Avoid overloading your vehicle and the tires. Putting too much weight in your car will put a higher load on the tires and shorten their lifespan by introducing dry rot and cracks.
• Protect the tires from UV exposure when leaving them in the sun. You can use cardboard or tire covers, but a full vehicle cover is recommended, as it will also protect your car's paint.
• Use the right tires for the weather conditions. For instance, using summer tires in the winter can introduce cracking and vice-versa.
• Replace your old tires on time, even if they have enough tread depth left. It is generally considered that you should change the tires every 6-10 years, depending on the model. Still, I wouldn't go higher than eight years, even with high-quality premium tires.
• Purchase tires from reputable manufacturers. Experienced tiremakers put various components in the rubber compound to minimize dry rotting and cracking and prolong the life of their products. In contrast, manufacturers of very cheap tires just put the cheapest materials they can find to maximize profits, which accelerates dry rotting and cracking.
• Store your tires properly. If you use a combination of summer/winter tires, make sure to store the set you are not using in a cool, dry, and dark place. Meanwhile, if you leave your vehicle stationary for longer periods, make sure you inflate the tires to the proper pressure and, if possible, lift your vehicle so that there is no load on the tires.

Conclusion

Cracked tires might not seem dangerous, but they can be a significant safety hazard, and using them is not recommended. Thus, make sure you inspect your tires regularly to see whether cracking has appeared, but also for other issues like bulges and worn-out tread. It will only take a few minutes of your time, yet it will make your daily driver much safer!