Bad turbo?
 

Half gallon of oil in the last week. Some white smoke at times. I imagine a bad turbo?

what exactly makes u think it is the turbo? have u pulled your intake off to see if theres alot of oil on the compreser wheel? grabed the shaft to see if there is any play in and out? are u sure you dont have a external leak? how much blow by does it have? more than normal? have u checked ur coolant to make sure it hasnt gone there?