e.g. stands for exempli gratia (Latin) = for example.
"I like fast cars, e.g. Ferrari and Porche"
In the sentence above you are simply giving an example of the kinds of cars you like - Ferraris and Porches.
i.e. stands for id est (more Latin) = that is (in explanation).
"I like fast cars, i.e. any car that can go over 150mph."
In this second sentence you are giving an explanation of what you consider to be fast.