A good wheel alignment is essential to the handling performance of any vehicle, motor sport or otherwise. Alignment is for the most part determined by the angles and positions of three components of front suspension: caster, camber, and toe.
The angle of the caster is determined by the angle between vertical, and the front wheel kingpin when the vehicle is viewed from the side. In general terms, a larger caster angle will lead to heavier steering, but also better straight ahead drivability and better steering wheel return. Front wheel drive cars commonly have a lower caster angle (between 1 and 4 degrees) than rear wheel drive cars (between 4 and 10 degrees).
The camber angle is a measurement of the angle between the plane of the wheel (when viewed from front or behind) and the vertical. A negative camber describes the wheel leaning towards the car, whereas a positive camber describes it leaning away from the car. A negative camber is often set on cars which require good cornering capabilities, but not extremely accurate control. A positive camber is more restrictive on cornering, but useful in achieving better initial handling response and steering wheel return. It should be noted that high degrees of camber (both positive and negative) often results in sever shoulder wear of the tyre.
The toe angle is measured from above or below the vehicle. This can best be described by the position of the front wheels when the steering wheel is in the straight-ahead position: if the wheels are pointed towards the middle of the car, they are said to be 'toed in', whereas if they are pointed towards the outside of the car, they are 'toed out'. The setting of the toe angle is often set to minimise irregular wear (usually caused by high camber angle). Most passenger cars have a slight toe in, while competition cars have a toe out.