I have been trying to save gas during my commute. Efforts to do so was by implementing hyper mileaging.  We  i started off by opening the windows rather than the air conditioning. Then by coasting half the block rather than leaving my foot on the gas pedal and braking 40 feet from the intersection. And lastly, by driving at or below the speed limit. By doing so, i was able to achieve 23 MPG in the city compared to a previous 18 MPG. Thats a difference of 5 MPG. Read more...

On the highway, i have improved from 24 MPG to about 28 MPG. I believe i would have gotten better milage, if i was driving a long rather than in a carpool, as the added weight of 3 other passengers and AC decreased my average. A interesting tool would be a scan gauge that tells what the car computer is registering as the fuel consumption and MPG. 

ScanGauge II 3-in-1 Compact Multifunction Vehicle Computer with Customizable Display asin: B000AAMY86