Too small. Percentage difference is 3.4% smaller in overall circumference. Max difference is 2.5% ideally. Best to keep the percentage difference as small as possible.

225/45R17 91V is usually for C segment cars.
225/50R17 94V or 215/55R17 94V is usually for D segment cars.

Just stick to OEM size. The engineeers that designed the car know whats suitable for the car. Too small might affect safety such as traction/stability control systems. 225/50R17 is pretty common anyways. Lots of choices.