There is probably no other consumer product that is subjected to the same harsh environments that a tyre experiences. As it rolls through its life thousands of times a day while bearing the weight of your vehicle, it is stretched countless times while being simultaneously exposed to sunlight, heat, cold, wet, corrosive brake dust, and harsh chemicals.
Given that all tyres are made of rubber they have to be designed to withstand all of the above. Modern-day tyres have anti-ageing chemicals in their compounds that help combat the elements and extend their life. Considering all the tough job that a tyre has, these anti-ageing compounds do their job rather well. But only up to a point.
THE MAIN CULPRITS
and heat, will eventually take its toll, causing the rubber to lose some of its springiness and firmness and allowing cracks to surface.
Ozone cracks usually develop in the sidewalls or on tread grooves. These cracks are usually cosmetic and should not affect tyre performance, especially if they don’t go beyond the rubber’s outer surface.
As opposed to a vehicle parked in a garage, the tyres on one that is parked outside will be constantly exposed to the sun, escalating the chances of cracking. Other offenders include curb-abrasions while parking, and frequent use of tyre cleaners and dressings that tend to remove some of the tyres’ anti-ozone and anti-oxidant protection.
Cracks caused by exposure to the sun or excessive cleaning will appear on the outward-facing sidewall of the tyre, with the inward-facing sidewall seldom affected.
Interestingly, another cause of cracks forming is infrequent use of the tyres. Tyres on vehicles that are not driven regularly or those with low annual mileage are more prone to cracking.
For show car owners, or motor home and recreational vehicle owners who only take occasional trips, this can be a frustrating experience.
A tyre warranty mainly covers manufacturing defects. In the case of ozone cracks, this warranty applies only if the cracks are escalated over a very short period, as ozone cracking is part of the natural wear and tear of a tyre.
Cracks due to misuse or poor tyre maintenance practices such as driving on a tyre that was flat, underinflated, overinflated, or overloaded show up quite differently. If an interior inspection of the tyre unmistakably shows that the cracks were due to these conditions, the manufacturer's warranty will not apply.