Tires: Guide to Maintenance and Safety

Dangers of Uneven Tire Wear

Many drivers are surprised to learn that uneven tire wear can cause significant mechanical issues beyond just a bumpy ride. When tires wear down unevenly, or when tires of different tread depths are mixed on the same vehicle, the wheels end up rotating at different speeds. This is especially problematic for all-wheel-drive (AWD) vehicles.

Replacing only one tire on an all-wheel-drive vehicle can result in the new, larger diameter tire to rotate at a different speed than the older tires, potentially damaging the vehicle's differential or clutch. The vehicle's computer may misinterpret these varying wheel speeds as slipping, causing the differential clutches to constantly engage and slip, which can eventually lead to costly repairs.

Why Underinflation is Your Tire's Worst Enemy

Running over a nail is a common cause of flat tires, but catastrophic blowouts are usually the result of heat and underinflation. Driving on underinflated tires causes excessive flexing in the tire's sidewall, which generates dangerous levels of heat that can break down the rubber and lead to a blowout.

"A blowout isn't usually just hitting a nail and blowing out. A blowout is having a nail in there, running it low, getting it really hot, and then finally blowing out." -James Church, owner at Oxford Automotive Tire & Repair 

When a tire is driven while low on air, the inside of the sidewall begins to shred, leaving a pile of rubber debris inside the tire cavity. To prevent this, drivers should monitor their tire pressure regularly and never ignore the TPMS (Tire Pressure Monitoring System) light on their dashboard.

Repair vs. Replace: Realities of Tire Damage

When you get a flat tire, the hope is that it can be patched. However in our experience, only about 25% of damaged tires can be safely repaired, while the other 75% require replacement. This is largely due to where the damage occurs.

According to industry standards, punctures located in the tire's sidewall or shoulder are not safe to repair, which means the tire must be replaced. Only punctures in the center tread area are eligible for safe patching.

Interestingly, the position of the tire on the car also plays a role in how it sustains damage. The rear tires are more likely to pick up nails and road debris because the front tires often kick the debris up so that it stands on end before the rear tires roll over it.

Lifespan of Tires: Age and Compound

Tires don't just wear out from driving. They also degrade from age. Tires generally begin to have an increased risk of dry rot and degradation after about five years of age, regardless of how much tread is left.

If you're buying a used car or driving a vehicle that sits for long periods, it is crucial to check the age of the rubber. The age of a tire can be determined by checking the Department of Transportation (DOT) code stamped on its sidewall: the last four digits indicate the week and year of manufacture.

When purchasing new tires, consumers often face a choice between different rubber compounds. The warranty mileage is often a good indicator of the tire's hardness.

Tires made with harder rubber compounds generally offer longer tread life warranties, but they tend to produce more road noise and provide less grip compared to softer rubber compounds.

Maintaining Your Tires

Proper maintenance is key to extending the life of your tires and ensuring a smooth ride. Many drivers mistakenly believe that a wheel alignment will fix a vibration or handling issue. In reality, alignments prevent the uneven wear that eventually causes those problems.

To keep your tires wearing evenly, rotation is essential. To ensure even wear and maximize lifespan, it is generally recommended to rotate tires every 5,000 to 10,000 miles.

• Check pressure monthly: Keep tires inflated to the manufacturer's specifications.
• Rotate regularly: Move tires front-to-back to balance out the faster wear that occurs on the steering axle.
• Inspect visually: Look for signs of feathering, dry rot, or sidewall bubbles.

Tire Maintenance and Safety: Conclusion

Tires are the only point of contact your vehicle has with the road, making them fundamental to your safety. Understanding the causes of uneven wear, the dangers of underinflation, and the importance of regular rotations, can help you maximize the lifespan of your tires and protect your vehicle's drivetrain from costly damage. Remember to check your tire pressure regularly, check the age of tire rubber, and never ignore early signs of wear.