I bought my highlander about two months ago. I was disapointed with the MPG as well. Now I am a little bit happier now since the MPG is improving. The key is to maintain 40 miles per hour using battery only. I found out that the best way to improve mpg is maintaining speed using battery only. 40 miles per hour is the best speed to do so on a relatively flat or small uphill. I have short drive to/from work (7 miles). I am happy getting 28 mpg.