I couldn't say this for fact, but the way the Mustang and Camaro get such great (for the circumstance) highway mileage is that sixth gear. Amazing it took so long for Ford to pop a 6th gear in, but a lot of vehicles now seem to be adding an extra gear for that reason. I couldn't see why else they would be taking a perfectly good 4 of 5 speed and upping it.
I mean the standard 'Vette sees an improvement in FE with the 7 speed standard than the 6 speed auto. Source:
Compare Side-by-Side
I know there is more loss when one goes gear by gear, but c'mon, if one isn't skipping gears when it's appropriate, they probably don't care or understand FE. The 14 'Vette with 460 HP is quoted the same highway mileage as my Mustang with only 305.
Come on son!