2001 - June Prius 16500 miles
I have a 7 mile (no highways) drive to and from work in Orange county California. (No hills all flat) my average mileage is 38.046 (life time) with my last tank only getting 40.36 aver. it has been dropping over the last 5 or so tanks. I have never averaged higher then 41.3 per-single tank. I use premium gas.
I have noticed that the car seems to be "holding back" at times, that is to say at speeds and conditions were it use to jump into hybrid mode (50MPG or higher on the display screen) it doesn't any more and stays in the high 30s. If it were a regular automatic car I would say that it is not shifting correctly.
Does anyone have any advise on what might be wrong?