Toe
The angle at which the wheels point inward or outward relative to the vehicle's centerline when viewed from above.
Toe is the most critical alignment angle affecting tire wear. It describes the direction the wheels are pointing relative to the centerline of the vehicle when viewed from directly above. Toe is measured in fractions of an inch, millimeters, or fractions of a degree.
Toe-in (or positive toe) occurs when the front edges of the tires point toward each other, resembling a pigeon-toed stance. Toe-out (or negative toe) occurs when the front edges of the tires point away from each other. Zero toe means the tires are perfectly parallel to the centerline of the vehicle.
Proper toe settings ensure the tires roll straight down the highway without dragging sideways. Incorrect toe settings cause rapid, feather-like wear across the tire tread, which can quickly ruin a set of tires. Symptoms of bad toe settings include a crooked steering wheel when driving straight, the vehicle darting or wandering, or squealing tires on smooth turns.
Toe is adjusted during a wheel alignment by lengthening or shortening the steering tie rods. It is highly sensitive to potholes, curb strikes, and worn steering linkages like tie rod ends or steering rack bushings.