[DWPC]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">How 2 similar weighing vehicles (outside of aerodynamics) can have 2 totally different engines (a V8 vs an inline 5) and get the same gas milegae! </div></BLOCKQUOTE>

It IS the aerodynamics! Drag goes up with a cube factor. The H3 is a box (actually a bunch of boxes stuck together). Compared to the H3, the TB is downright streamlined. Going from 70 to 80 increases your H3's already high drag dramatically.