Say a car is consuming 1 qt. every 800 mi. and the owner keeps topping up with new/fresh oil. If an analysis is done after say, 7-8k mi., will anything be different from a car in which the owner doesn't have to add a drop?
Likewise, if someone was using the "incorrect grade" eg. a 10-40 instead of a 5-20...how would this show up on an oil analysis?