Originally Posted by Diamondback
It actually drops .8 at 65 for some reason and and drops .5 at 70, don't ask me why. And by best mileage I mean on the freeway.
I've gotten 42.1 mpg by averaging 65 mph on the highway including some time around town. 470.1 miles/11.176 gallons of gasoline.
I also didn't use the cruise control and locked the car into 6th gear.
I've never seen better mileage at higher speeds. The theoretical maximum mileage would be at the lowest possible speed that allows you to maintain 6th gear (which for most 2012s was 35, but after the later 12B37 and all 2013 models seem to not shift into 6th at all until after 40 mph/ 1500 rpm in 6th.