We just bought our first Hybrid. 14 Prius Plug In Advanced, I assume that is PIP for short. Very nice car so far. The technology is very cool, still figuring it all out. Safety Connect is just like my buddies Tesla. Ha ha. Windows are tinted already and will definitely get some different wheels and tires. Those little bicycle tires just won't cut it.
Sorry to see you abandon fuel economy, but welcome anyway. One wonders why get a Prius if not for the MPG? (You may never miss the 5 to 10 MPG loss from switching wheels and tires, I would. I miss the 10 MPG loss from needing a station wagon)
I doubt OP has a clear idea how his tyres/wheels choices will affect his fuel economy, but it seems he likes the toys aspect of the car. Good for him, and good for Toyota for putting another SULEV+, 40+ mpg car on the road. I'll wager that doubles his previous car if he had one.
I don't have a clear idea on MPG, guilty as charged but I will do my research. Having said that my thoughts are that the upgraded wheels will look better and the car will handle better at higher speeds. I know that driving on the SoCal freeways at 70 MPH and the very small narrow tires the car wonders A LOT. At the end of the day I may not get new wheels. To answer the other question my previous car got 20-23 MPG so I am still way ahead ;-)
Lightweight wheels will have less impact than heavy wheels, while wider wheels and tires have an aerodynamic downside, weight seems to be the killer. Always try for Low Rolling Resistance tires.
Welcome to PRIUSchat!! You will love your new 2014 Prius, There are many good threads on PRIUSchat that can help you. Enjoy your new ride!!