That depends...
87K on the 89, runs like new
149K on this 92 wrangler and it still runs fine:
We also have a 98 honda with 184K that also runs great.
All cars get regular maint. and things fixed as required... which is often with the Jeep but it has almost 150K on it and we beat it senselessly. Moral of the story... 20 years, 17 years and 11 years, cars are built to run. I would expect many many thousand happily driven miles should be expected.
Mine will stay low but thats b/c we have 6 cars and really only drive the Honda (60 miles one way to work) everyday.