There is no ACCEPTABLE reason, I agree, unfortunately it is seemingly becoming very common. The Ecotech GM mill in the Terrains etc., used to be a solid eng. for them, butBut there is no reason for these newer cars to be consuming oil. It causes all sorts of problems long term. There is no way using a quart of oil every 1000 miles is considered normal
now they have oil consumption & timing chain issues, I put a 2.5L Subaru engine in a car I'd checked over for the dealer, it was full & clean when it left..........less than 3500 mi.
later it locked up. The galley feeding the pass. side bank taps the main at the rear of the eng., then the oil has to work it's way back to the frt. of the head, the frt. cam journal
seized & the composite cam sprocket exploded thru' the cover. Subey says 1Qt./1K mi is normal....WTF?