General terms:
* Motor car: A general term for any self-propelled rail vehicle.
* Self-propelled car: A simple and descriptive term.
* Railcar: A broad term that can refer to any car on a railroad track, but often implies a self-propelled unit.
Specific types:
* Diesel locomotive: A self-propelled car that uses a diesel engine to generate power.
* Electric locomotive: A self-propelled car that uses electric motors to generate power.
* Railbus: A small, lightweight self-propelled car used for passenger service on branch lines or short-distance routes.
* Multiple unit (MU): A self-propelled car designed to be coupled with other similar cars, often used for passenger trains.
* Diesel-electric locomotive: A type of locomotive that uses a diesel engine to generate electricity for electric motors.
* Electric multiple unit (EMU): A multiple unit powered by electricity.
The best term to use depends on the specific context. If you are referring to a general self-propelled car, "motor car" or "self-propelled car" would be appropriate. If you are referring to a specific type of self-propelled car, you should use the more specific term.
