We drove to WDW back in February and we weren't in a hurry and amazingly enough the traffic wasn't too bad. I did use ECO Pro and kept the speed around 70mph because of all the big hat boys patrolling the interstate, especially in Georgia. Best was the 29.1mpg on the state roads before getting on the interstate. Got 27.9mpg on the interstate.
BTW, used hands-free driving probably 85-90% of the trip. Because the 4-lane state highways were divided, the driving assist plus was available. It was amazing how much more relaxed I was when we arrived, compared to previous trips, when I had to touch the wheel every 7 seconds (before the latest update) or grip the wheel for the entire trip (before getting the X7 last June).
Just checked my February review and a 29.5mpg snuck in there somewhere.
