Engine oil consumption is caused by a number of factors. The most common causes include worn out oil control rings on the piston, brittle valve stem seals, worn out gaskets and seals in various parts of the engine room.

Some cars are sensitive to PCV, positive crankcase ventilation system. So, check if the PCV is working as designed. In particular, GDI, gasoline direction injection engines tend to consume more oil than conventional port injection system.