[Big time]

For instance a Prius engine could be only 1 liter displacement.

For traffic jams only the electric motor is used.
For boulevards the gas engine is turned on.
For extreme power demand situations, like uphills or when passing tractor trailers the electric engine could be used to supercharge the engine.

Its because a supercharger makes the engine produce more power than the power the supercharger takes to rotate.

Supposedly this is the reasoning behind 2014 Formula 1 turbo engines, switching and clutching between electric generator and motor for the supercharger.