So I believe it's been around 3 days total I've been ACTUALLY driving since I found this place and the list of things to do and change my driving habits.
I've been coasting a lot more, and when parking turning off the car to "coast" into place.
1. I've dropped 5mph on the highway to go back to the "sweet spot" on my Z. It's right at about 63mph indicated, i have aftermarket gauges, so it's really about 60mph to 59mph. Still pretty well with the flow of traffic though the people that /do/ pass are going pretty slow past me.
2. Coasting in Neutral up to a stop from a distance instead of gassing or light gassing. Or in traffic when it's coming to stop and go i can usually coast from a distance as it put me in a nice spot well behind traffic this morning (and the previous day) allowing me to either coast in Neutral or catch up as traffic started moving. Funny thing is some other people behind me followed, coasting, saving them a bit too :P
3. Coasting as I park as I come down from work my car actually builds momentum in neutral so no need to be in gear, halfway through to my spot i can turn it off and just turn into my spot with no hassle. Done this going places like the store too granted no one is around (it's nice to have power steering if you need it in a parking lot should something arise).
4. Coasting in areas with momentum. My driveway slopes, rather than going from 1st to second to get to my stop sign i stick it in 1st, get to 10mph and coast to the sign as it builds a bit of momentum... same with the upcoming light before I head to work.
5. Turning off the car in heavy traffic. Some of our lights are VERY LONG, I'll just turn it off, wait, and turn it back on after it goes again (by the time my end of the traffic moved it was probably a minute or more).
All in all, these simple little things seemed to use quite a bit LESS gas. I normally use $20 a week (which when gas prices were low was over 5 gallons, around 5.2-5.5), now I use $20 a week and last week i got 4.8 gallons and STILL had gas left on my quarter tank (about 1/2 of a quarter of a tank) left at the end of the week. Not bad.
I still need a scan gauge to KNOW what I'm getting, which will be exciting to see how good these are helping. But either way, just a change in these SMALL habits end up adding up long term.