they use oil from factory, its worth trying a cleaning agent ie i use seafoam in the oil for 50 miles tops then change oil this will clean the piston rings of crud even worth dropping some in the spark plug holes and leave over night then crank engine with no plugs in, its one of those kill or cure as if its dirt related oil use this stuff will clear it, but if engine is just worn out it might make it worse.
also worth checking the intercooler ie pipe off see how much oil has collected in bottom of it,, if a lot then turbo seals failing if none its engine related, worth finding out where the engine runs temperature wise as to high due to thermostat playing up or temp sensor or jockey wheel lack of grip to water pump can cause to much heat this thins oil this makes them use oil big time,
also worth checking the intercooler ie pipe off see how much oil has collected in bottom of it,, if a lot then turbo seals failing if none its engine related, worth finding out where the engine runs temperature wise as to high due to thermostat playing up or temp sensor or jockey wheel lack of grip to water pump can cause to much heat this thins oil this makes them use oil big time,
