Just to add physics to answers - to burn fuel you need two thingies, one is fuel, the other oxygen. Fuel is almost uneffected of the turbo aspiration, but the crucial point is air/oxygen. At sea level it does not really matter, as there is enough oxygen to burn fuel, but if you are getting higher and higher you will notice that you run out of oxygen first, not fuel ;-) - remember? If you now have the same engine, one normal one turbo, you will find out that the turbo is shuffling more compressed oxygen to you fuel2noise conversion unit. So, the higher you get, the more advantage you get in comparison by using turbo.