is this a vehicle that spends allot of time doing short trips? my 350 (207,XXX miles) did this and the 4cyl in my Suzuki (264,XXX miles) does it. there is a very long and technical description for this but it basically comes down to worn rings. The engine is burning oil that get by the rings (not enough to create blue smoke) and it replacing it with fuel at the same rate so the oil level always looks full..... then you take a long road trip and the lighter fuel burns off giving the impression of losing 3 quarts of oil. do a used oil analysis to confirm... its very common with diesels and common enough with a gasser.
