I was working at an airport as a aircraft fueler and we would help the mechanics preflight aircraft that had a rebuilt engine installed. For the first 20 hours (filter changes every 5) they were instructed to use aeroshell 80 or 100 (40 or 50 weight) non detergent mineral oil. This oil is designed to encourage wear in all the tight spots in the engine and to get the rings to seat. The high detergent and synthetic oils do not allow the engine to wear in properly, as mentioned with the oil burning WV. If parts are machined to very close tolerances and the rings are capable of sealing without much run-in, the regular oils are fine. If not, the non detergent oils allow high areas to wear and the particles to drop into the pan instead of being suspended and overloading the filter. New cars just don't need this kind of treatment. Why piston aircraft engines do, I'm not sure. Maybe because they run really hot and can warp somewhat, and the manufacturers want the engine's internals to learn to work together.