What does a turbo charger does to an engine, what it basically does is that it injects more oxygen to the combustion chamber, the effect would be more heat and power generated by the engine.
That is why engines with turbo chargers is a good thing to have for an engine especially if your engine has an added load like the A/C system where it gets the power from the spinning action of the crankshaft.
But what I had learned from my father is that it makes the engine use more oil, possibly from the negative pressure generated in the combustion chamber as it draws more oil from in-between the piston rings.
You can determine that it has an oil-consuming effect by monitoring the oil level of your engine. At least that was the thing that was told to me by my diesel mechanic father.
That is why he took off the A/C system of our car and before that the turbo chargers citing that it consumes more oil for the engine. Well true or not but the power that the turbo chargers gives to your engine is really something that is worth considering especially if you know that you will be going to use more power like wanting to have more speed, torque, and that extra energy to push it inn inclined roads and such for sporting and competition or show purposes.
