Just bought an 11 sport this week. Noticed while running down the highway at 65 with the cruise set that the ECO was not kicking in so I was getting 16 mph. I then slowed and set the cruise at 55 and the ECO kicked in and my mpg went up to 20.5. I then played around and found that the eco would only kick in while running 59mph or less on level road with no wind. Should this be the case or should I be able to run a little faster in ECO mode?