Aircraft engines are interesting. in the past 2 decades, aircraft engines have advanced very little or not at all. However, car engines have come a long ways as far as power and effiency in the past 2 decades. For example my Subaru Impreza has a boxer engine in it, Subaru uses the boxer because it began making planes before cars. When they started making cars they already had a good engine from the planes, and since then they have stayed with the boxer style. So essentially I have a modern day aviation engine in my car, but why havnt real aviation engines followed along?