I don't know how many times I have fought with my friends and family about this but it bugs me a lot. Some people say it's a motor. Some say its an engine. Well lets look at the difference. A motor is driven by an electrical source. An engine is fueled by fuel. Either gas,diesel, propane. A motor is found in the door of your car or truck which moves the window's up and down. An engine moves the Vehicle. So unless you have an electric vehicle you can't call whats under your hood a motor, it's an engine.
If you have a hybrid car well then its both. Gas or diesel engine for the highway speeds and a motor for 0-60.