Caster and Camber.

72bluNblu said
Yup, exactly. What amount works best depends on the chassis, suspension design and set up. All I know is my car is pretty happy at +6.5°. Some of the new performance cars run as much as +7 to +8° in their factory specs, the Dodge SRT8 Challenger specs call for a +7.3 to +9.3° range for caster on the left and +8° to +10° on the left. Base model Mustang's are also in the +7° to +8° range.
Click to expand...

You should do an alignment on some Mercedes cars. Some of them have as much as 12* caster. So drastic of an angle that you have to basically adjust caster, camber and toe all at the same time with each setting in mind. A small caster adjustment will throw everything else out a lot, so you have to make adjustments with all settings in mind. It's a trick for sure.