Toe-in is the angle of the tires and wheels toward each other. The amount of toe-in is normally a fraction of a degree. Measure the toe-in from the center of the tire treads or from the inboard side of the tires. Toe-in ensures parallel rolling of the front wheels and offsets any small deflections of the wheel support system, which occur when the vehicle is rolling forward. Incorrect toe-in results in excessive tire wear and unstable steering. Set the toe-in alignment last in the front wheel alignment procedure.

Linear Sum Toe-In is the distance between the front wheels. The toe-in distance is less at the front of the axle (1) than at the rear of the axle (2). Linear Sum Toe-In is measured in inches or millimeters.

Angular Toe-In is the angle of the front wheel centerline (1), relative to the intersection of the forward projected vehicle centerline (2). Angular Toe-In is measured in degrees.