The number one hp robbing unit in your car is your radiator. It robbs you of power and mileage. As I was explained in auto shop in early college an efficent and very powerfull engine would not give up any heat. It would retain all energy for the best result. So what I'm trying to say is as engines get better they will get hotter. Look at a engine from say the 70's. You would blow the radiator by the time most modern engines are warmed up.