In car handling, slip angle is the angle between a rolling wheel’s actual direction of travel and the direction towards which it is pointing (i.e., the angle of the vector sum of wheel translational velocity v_x and sideslip velocity v_y). This slip angle results in a force perpendicular to the wheel’s direction of travel — the cornering force. This cornering force increases approximately linearly for the first few degrees of slip angle, then increases non-linearly to a maximum before beginning to decrease. (This is directly analogous to the coefficient of lift in aerodynamics.)

The slip angle, α is defined as