Steering Axis Inclination (SAI)
Steering Axis Inclination is the inward tilt (angle) of the strut assembly with respect to a vertical line to the road surface. SAI raises the vehicle when the steering wheel is turned, which results in the self-correcting forces that cause the front wheels and steering wheel to return to a straight ahead position after cornering.
SAI is not adjustable, but is affected by damaged suspension components.
Most current alignment equipment can measure SAI and can aid in the diagnosis of damaged parts. Bent strut or spindle assemblies are common causes of incorrect SAI readings.