There are also more caster and camber built into the chassis on the passenger side of the car by the manufacturer to help compensate for road crown. This helps the car track true given that most states build in 2-6% cross slope to aid in the water evacuation from the road surfaces. Ever notice that the left side of most motorcycle tires wear before the right side? That is due to the road crown...
On a level surface, the tires on the driver side of most cars will appear to be be out further than the passenger side but once in motion the road crown differences typically make up the difference due to how it loads the suspension...
This was all passed on to me after a lengthy discussion with some suspension gurus after I had the very same questions after installing an aftermarket K member and tubular a-arms. I never looked at the tires that closely until I had to spend the time squaring the K and re-squaring since I couldn't get the tires even. The passenger side always sat a little more in and a little further back.
On a level surface, the tires on the driver side of most cars will appear to be be out further than the passenger side but once in motion the road crown differences typically make up the difference due to how it loads the suspension...
This was all passed on to me after a lengthy discussion with some suspension gurus after I had the very same questions after installing an aftermarket K member and tubular a-arms. I never looked at the tires that closely until I had to spend the time squaring the K and re-squaring since I couldn't get the tires even. The passenger side always sat a little more in and a little further back.