By the way, I came up with that 100,000 mile car lifetime number
because Clay Ford Jr. quoted it a couple years ago. That's sort of the
basis of the 100K emissions warranty too I believe. They can and do go
lots longer, but engineering shoots for that mark because they plan on
you being out of it by then. I too remember when engine rebuilds were
common at 50K and valve jobs even more often. Many two-ply tires would
not last 20,000 miles. Newer is better in many ways.