My FEH's sweet spot is between 40 and 45 mpg. However, my commute is 45 miles 1 way and 90 miles round trip. I have also noticed my FEH does better is heavily congested traffic (which allows more use of the EV mode when stop-and-starts are gentle.) I was also told to try to get my FEH to stay in EV mode up to 35 miles per hour. When I try, my ICE kicks in around 30 miles per hour. However, I found I can get the ICE to turn off around 35 miles per hour and then maintain my speed for short periods in EV mode. I normally get around 33 mpg with my FE-friendly AC running.