Steering geometry — definition of the included angle In front suspension/steering geometry, the “included angle” is defined as the sum of which two alignment angles?

Introduction / Context:
Accurate interpretation of alignment angles is essential for diagnosing tyre wear and handling issues. The “included angle” is a derived angle used by alignment machines and service manuals.

Given Data / Assumptions:

• Front-steer vehicle with measurable camber and steering axis inclination (SAI, also called KPI).
• Static alignment readings with vehicle at curb load.

Concept / Approach:
The included angle equals camber (wheel tilt relative to vertical) plus the steering axis inclination (the inward tilt of the steering axis when viewed from the front). It does not involve castor (a side-view angle) or toe (plan-view settings).

Step-by-Step Solution:

Verification / Alternative check:
Alignment equipment prints included angle directly after entering camber and SAI; OEM specifications list acceptable ranges.

Why Other Options Are Wrong:

• Castor is a side-view angle; toe is a plan-view setting; neither forms the included angle with camber.

Common Pitfalls:
Confusing SAI with castor; misinterpreting sign conventions causing apparent discrepancy with specs.

Final Answer: