I currently am driving an 08 Altima (4 cyl) and have just been using the build in guage for my MPG's (if that's what you mean).
I used to get about 27 MPG's and I have just since been using some basic strategies (been trying the P&G and mostly maintaining a more efficient speed on highways). I now get about 32 MPG's just from making a few simple changes... I must have really been a lead foot... ha.
Still working on it but not ready to try the more extreme methods quite yet