Well, rake me over the coals all you want. I put a quart in my pops 200,000 mile 98 Blazer before he left on a long trip. The truck has a decent rear crank seal leak and usually would have consumed at least 3/4 of a quart on a trip like this. Just checked the oil; right where it was before he left. The truck also got 24 mpg
I dunno if the seal got cleaned or the ring packs got cleaned out or what, but whatever happened is good.
I can't wait for the "harsh solvent will kill your engine" statements to follow.