Just drove mine from CT to Montreal - probably averaging 70-75 mph. The computer readout is saying that I averaged 35.0 mpg for the trip which included going through the Berkshires on the Mass Pike and Adirondacks mountains on the Northway in NY. I topped off the gas tank before heading out this morning and only needed 2.1 gallons to replenish the tank after driving 104 miles which works out to 49.5 mpg. (I learned the lesson that you don't want to try to squeeze any extra gas into it - it tends to shoot all over - when it is full, it is full!) You won't be disappointed - I do need to spend more time learning about the Sync and Nav setup - although at least the basics are pretty straightforward.