As I understand it, this is related to cylinder deactivation. My 2010 started sucking oil at about the same mileage as yours, and in similar quantities. Apparently there is a blow-off valve that provides additional crankcase ventilation which only opens during cylinder deactivation. Some people have constructed baffles to go inside the crankcase behind the valve and claim that it radically reduces oil consumption. Others have argued the oil loss is due to excessive cylinder blow-by causing more than expected airflow through the valve and managed to get new engines under their warranty. Others just have their ECM reprogrammed to disable cylinder deactivation altogether. All of these are effective methods of "solving" the problem.
I have just been living with it, but the oil consumption is right about at the limit of what catalytic converters can tolerate... I'm kind of biting my nails on that one.
