3.91 gears for shorter 60 mph trips

I think we are so used to overdrives anything over 2000 rpm is for accelerating.

I agree X2. Back in the 1970s my big block Mopar used to cruise at 65 - 70 mph with the tach showing 2200 - 2500 rpm while in 4th gear. The sound of the engine with its headers and glass packs was pleasing. Of course, if I wanted to listen to the radio, I had to crank the volume up to eleven!