The truth is Toyota Prius, Greener Car ,Which is greener: a Toyota Prius or a Toyota Corolla? They're both roughly the same size, and when you think quick, it seems that the Prius would be the no-brainer choice for greenies. The Prius, after all, gets an EPA Combined 50 mpg, while the Corolla gets 30 at best.
But if you think a little more about it, the question gets a little more complicated: What about the extra raw materials that go into a hybrid's battery pack? What about its longer assembly process, and its more complex powertrain?