Thrust discrepancy

Ultimate reaching point of wheel alignment and geometric axle construction correction is to overlap 2 centric steering positions, one is that of automobile it self and another is that of driver's Sixth sense. Very abstract representation as upper description is, I do not imagine another way to explain about the title.
So, the final adjustment and correction would be performed and established not only by precise scaling but also by the information from the sense of the driver's 5 senses including 6th one.

Remember here that too much discrepancy of thrust is corrected by self steer reaction automatically performed by the effect of applied SAI angle and caster angle resulting self steer phenomena, though this is a poor low level conversation.

In case of thrust angle error, there exist two steering  centric position, 1st one is the position to keep straight running that is directed by rear total toe direction, rear thrust and 2nd one is the direction of frontal axle direction frontal thrust. This frontal thrust is dictated mainly by the forces from self steer phenomena on both side.
The displacement of vector directions for frontal and rear axles is called as Thrust Angle.

The thrust angle correction as a final step on BC7 SUBARU Legacy LSi US model would be performed by actual running test on the highway by adjusting rear lateral arm adjusting construction moving outside to increase rear right toe-in, the rate would be about 0,300mm to 0,600mm. Now the discrepancy of two positions is about 1mm on steering column.

As for XH200 OPEL B-Vectra established, NCP10 TOYOTA Vitz established unintentionally because of torsion beam rear axle designing and SXE10 TOYOTA Altezza not yet established, also 11AD VW Super Beetle not yet on the way not so far but not so near.