What is a Tire Sidewall Damage & When to Replace the Tire?

Sidewall Tire Damage

If you ever experienced a puncture on your car’s tires before, you know that getting a puncture can be frustrating.

Luckily the most punctures are easy to repair and often repaired within minutes with a tire repair kit.

Unfortunately, damages can occur to your tires that are not so easy to fix, and in most cases, you need to replace the whole tire. A sidewall tire damage often causes this.

But what is sidewall tire damage, and how serious is it? Let’s Find out!

What is a Sidewall Tire Damage?

A sidewall tire damage is exactly what it sounds like; damage on the tire’s sidewall, meaning that the damage is on the side of the tire and not the tire tread.

You can often spot one by seeing a deep scratch or a bubble on the tire’s sidewall. This can come from a small accident or if you drove too close to the road’s curb. It can also happen because of sticks or other sharp things after the road.

A sidewall tire damage is really serious to drive around with, and now we will explain why.

Is it safe to drive on a tire with sidewall damage?

Deep Sidewall Tire Damage

A sidewall tire damage is not safe to drive around with. The sidewalls of the tires are much more sensitive than the tread area. In many cases, the damage is damaging the whole structure of the tire, and it can cause it to blow at any moment.

This does also depend a little bit on how big the scratch or damage is. If the scratch is small and super-shallow and does not reach the threads, it is probably not something you should worry too much about.

How much tire sidewall damage is too much?

Sidewall Tire Damage

A rule of thumb for determining how much sidewall tire damage is too much is that if you can see the threads in the damage, it is definitely time to replace the tire.

The threads are often located 1/8″ to 3/16″ (3mm to 4.5mm) into the tire, but to determine exactly if you need to replace the tire or not, you need to look at the damage itself.

If there is an air-bubble on the tire’s sidewall, you need to replace it straight away because there is a big risk that it will blow at any moment.

To be sure that nothing serious will happen to the tire, you should let an expert look at the damage.

Find a repair shop that is not selling tires and ask them. If you go to a repair shop that is selling tires, it is a big chance that they will want you to buy new tires.

Can You Repair a Sidewall Tire Damage?

Swelling Tire Bulge

A sidewall tire damage that reaches the threads should never be repaired because it damages the tire’s whole structure.

If the tire’s sidewall has a bubble, it is not fixable either, and small punctures should either not be repaired.

The only time you can glue together a sidewall tire damage if it is a super shallow scratch that is not reaching the threads.

However, if the scratch or damage is this shallow, there is no point in gluing it either, so I would say that you should never repair a sidewall tire damage.

Causes of a Tire Sidewall Damage

Sidewall Tire Bulge

There are a lot of things that could cause tire sidewall damage. Mostly it is because of sharp objects you were hitting with the sidewall of the tire by accident. It can also be caused by age or driving around with too little air pressure in the tires.

Here are the common causes of tire sidewall damage:

  1. Hitting a curb
  2. Under-Inflation
  3. Potholes
  4. Sharp objects
  5. Age 
  6. Overload 
  7. Manufacturing defects 

Is it bad to replace just one tire?

If you replace the tires on the drive wheels, you should replace both tires because the different tire diameters will cause stress to the transmission otherwise.

If you replace the tires on the rear on a front-wheel-drive, for example, you can replace just one tire.

If you have a 4wd car, it is always recommended to replace all four wheels because different tires’ diameters can cause stress to the differential or transmission, especially on European cars.

The best way to find out is to ask your authorized dealer if you can replace just one tire on your specific car model.

Is sidewall tire damage covered under warranty?

No, sidewall tire damage is most often considered damage you made yourself and not a manufacturer problem, and therefore it is not covered under warranty in most cases.

However, if you want to be sure, you can always ask or read through your warranty documents carefully because there are cases when you have a special car warranty.

Written by: Magnus Sellén

Founder, owner & main author of Mechanic Base. I have been repairing cars for more than 10 years, specialized in advanced diagnostics & troubleshooting. I have also been a drifting driver and mechanic for over 7 years.