Car Trouble Symptoms

You will notice the tire wear on the outside edge of the tire.

Possible cause

Wheel alignment problem - positive Camber.

Car Troubleshooting

The idea of "wheel alignment" essentially has to do with how straight the wheels are relative to your car's frame. Mechanics use the term "camber" when they are talking about the tilt of a wheel.  Specifically, a wheel has either :

1) Positive camber, 

2) Negative camber, or 

3) No camber.

If a wheel has a "positive camber", it's tilted outward or, away from your car's frame. If a wheel has a "negative camber", it's tilted inward or, towards your car's frame. If a wheel has no camber, it's not tilted - this is what you want.

As indicated in the problem, one (or more) of the tires is wearing mainly on its outside edge.  This means the wheel is tilted outward or, has a "positive camber". An outward tilt will, of course, cause the tire to wear on its outside edge.

What to do?

You' will need to have an alignment job done in your car. It's a good idea to have this done soon because the longer you wait, the worse the tire(s) will get. Some mechanics may tell you they can't do an alignment properly without first replacing one or more front end parts. If this is what a mechanic tells you, get a second opinion before proceeding with any such repairs.