Toe is the most important alignment angle when it comes to a tire’s overall tread life. The toe angle identifies the direction the tires are pointed compared to the centerline of the vehicle when viewed from directly above. Toe is expressed in either degrees or fractions-of-an-inch.
An axle is said to have a positive toe-in if you can draw an imaginary line through the center of the tires and it intersects in front of the vehicle. Negative toe-out happens when those imaginary lines separate from one another in front of the vehicle.
The toe setting is typically used to help compensate for the suspension bushings compliance and enhance tire wear. Toe can also be used to adjust vehicle handling since it changes as the weight of the vehicle is transferred to the front or rear wheels. Engineers can tune the suspension geometry and toe to make the vehicle more stable under braking or initial turn-in.
It is critical to remember that toe is not always zero or straight ahead. Some OEMs will specify a certain amount of positive or negative toe. These toe specifications could take into account bushing deformation as the tire is pushed rearward as a vehicle’s speed increases. Beyond that, a positive or negative total toe angle in the front or rear may make the vehicle more comfortable for the customer to drive.