Back in the early '90's the car that I used to take myself to and from work on construction sites used/leaked lots of oil. As I remember it was a qt. somewhere between 300-500 miles. Before I sold it I stopped changing oil in it and was topping it off with oil I'd drained out of my better cars at oil change that already had approximately 3K miles on it. When I sold it it had been over 31K miles since it's last oil change and the consumption seemed to be very close to what it was when I quit changing it. I'm not condoning this type behavior on most cars but, when one gets in pretty rough shape, loses lots of oil, and has practically no resale value I don't see anything wrong with it. I sold mine to friend. I told him about it's history. He had just got married and needed cheap transportation so I sold it to him for $250 and let him make payments until he got it paid off. I know he drove it for quite awhile after I sold it. I'm guessing 1-2 years. The reason he quit driving it is they passed emissions testing in that area and it wouldn't pass because it didn't have a catalytic converter. Last time I saw it I was on my way to work one morning, I met a load of crushed cars and it was on that load.
I never quit changing oil in this one but, an '88 Ford Escort I used as a daily driver had also got where it used a quart about 800-1K miles so I started topping it off with oil drained from my better cars. When I quit driving the Escort it had 518K miles I suspect I'd been adding used oil between changes for approximately the last 150K miles.
Neither of these cars smoked other than a puff when they were first started. I don't know what the compression was on the Chrysler but, when I quit driving the Escort the compression was 145-155 across all four cylinders.
