To clarify a little bit...
I had three adults (I may count for 1.5 actually) and a dog loaded just for a one week visit, nothing in tow, and was very light on the throttle. I avoided the downshift for hills when possible just because the revs were making the pooch nervous (one of them there vicious pit bulls). I didn't attempt to get up to speed quickly and just let the momentum build at what the drive train seemed comfortable with. The rig seemed to enjoy 55-60mph more than 65 anyway, I think that is the main factor for me.
I am sure that if I was looking to make time at 65+ and towing a car like most rigs that I saw on the road it would have been different. I will do the mileage each trip next year just for fun and see where it falls.
