What: Toe is the difference in the distance between the front of the front wheels and the distance between the rear of the front wheels. If the fronts of the wheels are closer together than the rear of the wheels, the difference in the distance is called "toe-in." If the fronts of the wheels are farther apart than the rear, the distance is called "toe-out." Almost all vehicles are designed with a certain amount of "toe-in, " measured in inches or millimeters.
Toe is the most critical tire-wearing angle. The purpose of toe is to ensure parallel rolling of the front wheels; but if either wheel has too much toe-in or toeout, the tires will sideslip. This results in a featheredged scuff across the face of the tire.
How: Toe is adjusted by measuring the distance between the front of the tires and the back of the tires at the tread and increasing the difference by turning the tie rod or steering links in or out.