Transmission revving up hill

welcome! normal. it's the tranny type. and coming down, your engine might run to burn off excess charge.

if you are concerned, take a new one for a test drive.

 

See if a dealership has a Prius c loaner or demo they could let you test drive on the same stretch of hill, maybe with a mechanic along, see if it sounds the same? Or at least just take yours up a hill with the mechanic along?

 

There are at least a couple of reasons why the Prius C's engine sounds often seem strange to new drivers:

1) The drivetrain uses a continuously variable transmission, so it doesn't have to step through "gears" while accelerating like a conventional drivetrain does. If you're not demanding excessive acceleration then the engine will usually run at a constant speed even though the car itself is speeding up.

2) The engine not only powers the drive wheels but can also apply power to the motor/generators to recharge the battery. In cases where the car decides that the traction battery needs recharging the power demand on the engine may increase or decrease even though no changes have been commanded by the driver. Thus, you may hear the engine RPMs going up or down even though you haven't done anything to cause it.

In terms of power, the C is optimized for getting great mileage while driving in the city. The engine likes to run in a narrow RPM range with modest power output and be supplemented by the battery when more power is needed in order to optimize efficiency. It has the power to climb hills, but you will probably have to depress the accelerator pedal further than you're used to and it can get pretty loud to let you know how hard it's working.