Which angle has the greatest effect on steering wheel return?

The angle that has the greatest effect on steering wheel return is caster. Caster refers to the angle of the steering axis in relation to the vertical axis when viewed from the side of the vehicle. Positive caster, where the steering axis tilts rearward at the top, helps to create a self-centering action on the steering wheel as the vehicle moves forward. This self-centering action is essential for returning the steering wheel to its neutral position after a turn.

When a vehicle is turned, the wheels will naturally want to return to the straight-ahead position due to the geometry of the suspension created by positive caster. This makes control and handling much more predictable, enhancing driver comfort and safety. A higher degree of positive caster typically results in a stronger self-centering effect, improving steering return after cornering maneuvers.

In contrast, while camber, steering axis inclination (SAI), and toe adjustments affect tire wear, cornering characteristics, and alignment stability, they do not significantly influence the steering wheel's ability to return to the center position like caster does.