Toe is the symmetric angle that each wheel makes with the longitudinal axis of the vehicle, as a function of static geometry, and kinematic and compliant effects. This can be contrasted with steer, which is the antisymmetric angle, i.e. both wheels point to the left or right, in parallel (roughly). Positive toe, or toe in, is the front of the wheel pointing in towards the centreline of the vehicle. Negative toe, or toe out, is the front of the wheel pointing away from the centreline of the vehicle. Toe can be measured in linear units, at the front of the tire, or as an angular deflection. An angle is the figure formed by two rays sharing a common endpoint, called the vertex of the angle. ...

In a rear wheel drive car, increased front toe in (i.e. the fronts of the front wheels are closer together than the backs of the front wheels) provides greater straight-line stability at the cost of some sluggishness of turning response, as well as a little more tire wear as they are now driving a bit sideways. On front wheel drive cars, the situation is more complex. Rear wheel drive was a common form of engine/transmission layout used in automobiles throughout the 20th century. ... Front wheel drive is the most common form of engine/transmission layout used in modern passenger cars, where the engine drives the front wheels. ...

Toe is always adjustable in production automobiles, even though caster angle and camber angle are often not adjustable. Maintenance of front end alignment, which used to involve all three adjustments, currently involves only setting the toe; in most cases, even for a car in which caster or camber are adjustable, only the toe will need adjustment. θ is the caster angle, red line is the pivot line, grey area is the tire Caster (or castor) angle is the angular displacement from the vertical axis of the suspension of a steered wheel in a car or other vehicle, measured in the longitudinal direction. ... A wheel with a negative camber angle Camber angle is the angle made by the wheel of an automobile; specifically, it is the angle between the vertical axis of the wheel and the vertical axis of the vehicle when viewed from the front or rear. ...

One related concept is that the proper toe for straight line travel of a vehicle will not be correct while turning, since the inside wheel must travel around a smaller radius than the outside wheel; to compensate for this, the steering linkage typically conforms more or less to Ackermann steering geometry, modified to suit the characteristics of the individual vehicle. The locking pliers is an example of a four-bar, one degree of freedom mechanical linkage; or a five-bar, two DOF linkage when the adjustment screw is considered. ... Ackermann steering geometry is a geometric arrangement of linkages in the steering of a car or other vehicle designed to solve the problem of wheels on the inside and outside of a turn needing to trace out circles of different radii. ...

It should be noted that individuals who decide to adjust their car's static ride height, either by raising or lowering, should immediately have the car properly aligned. The goal is to bring total front and rear toe settings to 0°, as toe is the major contributor to abnormally increased rate of tire wear. The common misconception is that Camber angle causes an increased rate of tire wear, when in fact camber's contribution to tire wear is usually only visible over the entire life of the tire. A wheel with a negative camber angle Camber angle is the angle made by the wheel of an automobile; specifically, it is the angle between the vertical axis of the wheel and the vertical axis of the vehicle when viewed from the front or rear. ...

See also

• Caster angle
• Camber angle

θ is the caster angle, red line is the pivot line, grey area is the tire Caster (or castor) angle is the angular displacement from the vertical axis of the suspension of a steered wheel in a car or other vehicle, measured in the longitudinal direction. ... A wheel with a negative camber angle Camber angle is the angle made by the wheel of an automobile; specifically, it is the angle between the vertical axis of the wheel and the vertical axis of the vehicle when viewed from the front or rear. ...

External links

• Camber, Caster, Toe - What does it all mean?
• Toe and Race Car Suspension Tuning