https://jalopnik.com/what-kind-of-fu...1839901794/amp
Despite some inaccuracies and bad comparisons I noticed in the article, it explains well that engine efficiency plays just an important part in fuel economy as coefficient of drag does. So some cars that are shaped like bricks (my Jeep) can still get good FE without making too many concessions to aerodynamics. Not something too many ecomodders consider as most cars here have small engines and have a fairly low cd already.