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Porsche: Why Are My Tires Wearing Unevenly?

There are a couple of reasons why the tires on your Porsche might be wearing unevenly. This article will help you diagnose and correct the problem to get you rolling smoothly once again.

By Brett Foote - April 14, 2015

This article applies to the Porsche 928, Porsche 993, and Porsche 997 (1978-2012).

Uneven tire wear can turn into an expensive problem, especially if you run a nice set of tires on your Porsche. Also, it can rob you of performance. The good news is, correcting uneven tire wear can be a quick and easy repair if you have the right equipment.

Materials Needed

  • Air compressor
  • Air pressure gauge

Step 1 – Check the tire air pressure

The most common cause of uneven tire wear is improper inflation.

Improper tire inflation is the most common culprit when it comes to uneven tire wear. Check your owner's manual, inside the door jamb, or on the tire sidewall for your tire's recommended air pressure range. Park your Porsche on a flat surface, and use your air pressure gauge to check the pressure in each tire. If a tire is not within the recommended range, inflate it using an air compressor. Alternatively, you can find air inflation pumps at many gas stations. It's also possible that your tires can be over-inflated, in which case you will need to let some air out. The graphic below demonstrates how various air pressure problems can cause different types of tire wear.

Figure 1. This picture shows various types of tread wear as well as their causes.

(Related Article: How to Check Your Tire Pressure - Rennlist.com)

Step 2 – Check your alignment

A misalignment can cause uneven tire wear when your tires aren't contacting the ground in a perfectly flat manner.

If you alignment is off, your tires will inevitably demonstrate signs of uneven wear. To determine if you have an alignment problem, inspect each tire. If one side of the tread is wearing faster than the other, you may have an issue with the toe, meaning that your tires are facing inward or outward. Rub your hand over the tread of the tire, and if you feel bumps similar to a saw tooth, you might have a feathered wear pattern. This is caused by excessive toe and caster settings. If one shoulder rib of the tread is more worn than the other side, you might have excessive positive or negative camber.

  • Figure 2. Heel and toe wear from a misalignment.
  • Figure 3. Shoulder wear from a misalignment.
  • Figure 4. Feathered wear form a misalignment.

Pro Tip

If you think you have an alignment issue, it's a good idea to take your Porsche to a reputable shop or dealer to correct the problem. While it is very possible to do it yourself, it's not an easy job. Plus, the professional cost isn't too prohibitive by any means.

(Related Article: How to Align Your Tires - Rennlist.com)

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