Oil consuming issues

I've been noticing my car is consuming a lot of oil in a short period of time. There was a leak on head cover gasket so on Dic 13 we changed the head cover seals and re-filled oil to max level on dip stick.
I've driven between 500 to 575 miles which is 4 long trips within the island and local commuting. When i checked my oil today and it is the lowest level mark on the dip stick. This seems to much oil consumption for just 4 trips and barely 3 weeks. I'm thinking of faulty piston rings or faulty turbo seals.
My car has 130K miles at the moment. I'm thinking of doing new cst4 turbo which has been sitting around for about 2 years, first before even thinking about piston rings. If anyone can share some light here based on your experience with the platform. Any ideas?

 

First step. Compression test and leak down test. Before trying to add a turbo to an engine with issues you need to get a snapshot of th engines condition especially if you are suspecting rings. I would do those even on a healthy engine.

Within this 130K mi, have you done the PCV valve? Whats your catch can contents situation like? any change?