why my 2003 toyota prius 24 mpg only?

None of our Prius customers have ever had such low gas mileage. Even if the check engine light is not on attaching a scan tool and looking at live sensor data to look at fuel trim values long and short term, look at air flow readings into the engine, and look at coolant temperature readings. Google "Prius poor mpg", look on Prius web forums some good articles This a great repair shop in San Francisco good articles on their web site http://lusciousgarage.com/blog/cat/repair/P5/ For theory of operation look at http://www.autoshop101.com/ look at tech articles, Genuine Hybrid Toyota training information is their.