What's the difference between car oil and motor oil?

I don’t think there are any differences between the two except for the titles. I’ve heard it called motor oil, engine oil, and car oil.

Apart from those mentioned above, you could look at other fluids for your car, whether they be oil based substances or not, and include them under the category of car oils. Examples of these would be automatic transmission fluid (ATF), brake fluid, and power steering fluid.

There isn’t a difference other than car oil being a specific kind of motor oil.

(don’t assume this to mean they’re interchangeable, they are not. Car oil is refined to a specific degree and a lot of other oils are not, or are even TOO refined). Think of it like grades of octane on gasoline.

I’ve been tinkering with cars for a long time, and I don’t think I have heard the term “car oil” used in reference to anything. If you are talking about the kind of oil used in the car’s engine, when you get an oil change, you are referring to motor oil, which comes in a lot of grades and weights. Cars also require transmission oil, which is a different thing altogether.