KPI or SAI

Cars generally no longer have kingpins and hence the term KPI is outdated.

SAI stands for Steering Axis Inclination and it will be referred to subsequently by this.

When viewed from the front the SAI is the inclination of the strut top towards the centre of the vehicle, and in all cases is positive.

SAI is not altered in the aftermarket, only returned to the factory setting, perhaps following accident damage. SAI gives driver feel to the steering and assists in unwinding the steering after steering lock has been applied, bringing the steering back to the straight ahead.

Included angle
Adding together the SAI and the Camber gives the included angle.
Understanding Included goes beyond the scope of this course.