Car choice for Reno/Tahoe?

I'm visiting Reno/Tahoe for the first time, and will be renting a car. Midsize or full-size? Does it matter? Not sure about roads/mountains. Plan to do some sightseeing while there, so will definitely do some driving.

Rent a car you'd rent anywhere else, in summer the roads around Reno/Tahoe don't compel any particular type of car.

Usually, you can get a different car for almost the same price! Check it out! The full size car gets about the same mileage as a medium size car. I've gotten luxury cars that get the same mileage as a medium or full size car. But people don't know that and opt for a medium size car thinking they get the same mileage!