nice write-up and review. Rep points for ya 
I also live in north Michigan.. not too much flat UP here, lotsa shifting from the 8-spd.
high-speed mileage:
pushing a giant brick down the highway at 78 mph takes a lot of energy...
the advantage in efficiency the V6 has is smaller at these high (er) loads,
so mpg is closer to that of a V8.
the Pentastar is awesome, but not quite magic...
I also live in north Michigan.. not too much flat UP here, lotsa shifting from the 8-spd.
high-speed mileage:
pushing a giant brick down the highway at 78 mph takes a lot of energy...
the advantage in efficiency the V6 has is smaller at these high (er) loads,
so mpg is closer to that of a V8.
the Pentastar is awesome, but not quite magic...