What happens when you don't change your oil for 84,000 miles?

I know a guy who leases a new vehicle every other year…and NEVER changes the oil or any other maintenance. Says he’s adding a quart every other week after the first year. I drove behind him once when leaving work one day toward the end of his lease…the car was leaving a nice trail of blue smoke. He bought nice cars too. Luxes, Cadilacs, Lincoln’s…

^
Hmmm…I wonder how many of his cars later wound up as Certified Pre-Owned vehicles on the dealer’s used car lot.