Supercharger/Increased MPG?

[GasSavers_goldie]

I am just starting to research the possibility of adding a supercharger (belt drive) as another mod to my Sierra (4.3L engine). In the scant perusing of threads on this subject I am unable to come to a conclusion as to wether or not this will be of benefit to increasing my mpg, assuming I stay with my conservative driving techniques. I am interested in hearing experiences from members about this subject. Meanwhile, I continue my research. Thanks in advance for the assisitance.