Ok I'm not even gonna bother reading the rest of the responses, but Turbocharged engines are more efficient than NA engines period. You are taking waste gas and turning it into power, and the engine doesn't have to work as hard to make the same amount of power. You are also adding back pressure in the exhaust which is another +1 for efficiency.
Im not going to argue with... Anyone about this. I have been beating this dead horse with people on these forums forever. I'm currently in the process of turbocharging my insight, and when I'm done, I'll post the efficiency gain results.
__________________
|