Alignment describes the way the tires and wheels are angled on your vehicle. There are three angles critical to an alignment:

• Toe: Wheels can be toe-in (wears tires on outside) or toe-out (wears tires on inside). Depending on your vehicle, one option will wear tires less than the other. For example, toe-in alignments are performed to compensate for friction that occurs while driving and pushes wheels apart. However, toe-out is the better choice on some vehicles, like many old front-wheel drives, because they were built in a way where the wheels pulled inward.
• Camber: Camber describes how your tires and wheels lean relative to being straight. There are two types of camber, negative and positive. With negative camber, the tire tilts in toward the vehicle. With positive camber, the tire tilts away from the vehicle. Like toe, your ideal camber depends on your vehicle and how you drive it, as well as road conditions. Most vehicles should have some camber to compensate for turns.
• Caster: Caster is the angle between the upper ball joint and the lower ball joint. The angle tilt can be forward (negative caster) or rearward (positive caster) and plays an important role in handling. Incorrect caster requires drivers to exert more effort steering and increases the rate of wear on tires.

Aside from experiencing problems with handling or irregular tire wear, you should request an alignment check whenever you install tires. This way, you can make any necessary corrections at the time of installation to ensure you’re in the best position to get the longest life from your purchase.