Welcome to another car enthusiast who's become enthusiastic about hypermiling. I found religion when my 160 mile roundtrip commute went from once a week to 5 times a week, and my STi's thirst started eating me out of house and home. A Honda Fit paid for itself in fuel savings alone! And it's a hoot to drive.
A few benefits that cross over:
- accelerating smartly up to target speed is good for fuel economy
- you can scorch the turns and say that you're "maintaining momentum"
- ditto declutching and getting up a good head of steam on downhills
- higher tire pressures improve both fuel economy and handling (up to a point)
- ditto aerodynamic aids such as underbody trays