You should replace tires when cracking is serious. If it's found throughout the tire's surface and extends deep into the surface, it's a sign that the compound isn't functioning as it should, and replacing them is necessary for your safety.

Is it bad if your tires are cracking?

But tread wear isn't the only factor to consider when it comes to tire safety. Cracked rubber can also render a tire unusable. Weather cracking can appear on both the sidewalls and tread faces of tires and is usually related to age and exposure to the elements.

Do cracked tires need to be replaced?

Damage – If the tires are damaged and cannot be repaired, obviously they need to be replaced. ... Dry rot – If your tires show any signs of dry rot, a.k.a. sidewall cracking, it's time to replace them. All tires that are 5-6+ years old are at risk for dry rot, but it may happen sooner or could happen a little later.