There's a lot to control out, but OOS 70mph tests deserve credit for index (hashing) EPA Range. It doesn't seem there's enough data to prove higher frontal areas create a bigger gap, but this should be intuitive (Cd doesn't reveal aerodynamics, by itself). The Gravity, like Tom's 60mph Escalade, probably improves range more quickly as you slow down. Conversely, the 70mph test represents a greater penalty as you speed up from the lower average EPA test cycle speed.