My wife, son, and I took my 2016 6 Touring on a six hour road trip to the Smoky Mountains today. Averaged 70-75 MPH through the mountains. And got 33 MPG. Not bad. Just cracked 40,000 miles as we hit Pigeon Forge.
We had the car quite loaded down (traveling for 4 days with a 2-year-old means bringing a lot of crap). But, we got lucky and didn’t hit hardly any bad weather or traffic.
For a long time on the way, I coasted downhill through the beginnings of the mountains. That helped offset the MPG loss from running the A/C all day and idling some at a rest stop.