Originally Posted by dyn085
I would think that his graph supports mine. If his second fill-up was 25ish mpg, he is averaging (roughly, no Excel backing) at or over 30mpg. Assuming that his first tank was (as many are concerned with) lower mpg than his second, he would be seeing well over 7 mpg's gained simply by the ECU/PCM 'learning'.
I am averaging 30.4 MPG over the lifetime of my ownership of the car. I get better with really long drives though.