For education, I have to point out why oil is good for cars and why oil is bad for cars, need help?

Oil is good because :
1) It acts as a lubricant
2) It Prevent the part from rusting
3) It prevent the parts from corrosion.

As well as oil is bad for cars because:
1) It reduce the efficiency of parts
2) It provide a path for conducting current and possible chances are there for short circuit.
3) If the oil get heated up the parts of car it may start burning thereby damaging the part.
May this answer be helpful if not then it is enough to get an Idea.....