My average over 11K is 6.5 l/100km, or 36.2 mpg US. I keep track in Fuelly and never overfill, always using premium Costco gas for most fill-ups. The best I ever got was 5.9 l/100km (39.9 mpg) on a fill-up after mostly benign highway driving.
According to onboard computer, I'm getting 41.3 to the gallon. Commute each way to work is about 25 miles with 5 stoplights. Majority of the drive is done on cruise control.