Exciting, nobody else has posted yet, so I need to try to be useful.
Well, "need" is relative…
Your post is over a full page in Word. I copied and pasted in order to handle it better. Please understand, I have only been on the site for several months, and I have only used the Ultragauge, so I cannot compare it to anything, but I will give you the best information that I can.
1. 750-780 is a 4% increase, so I would not call that "all over the place." My car does that, too. As I understand it, the car constantly changes the air\fuel ratio a small amount to make sure that it is where it wants to be
2. There are smartphone apps if you would rather have something larger.
3. I immediately changed one habit, but that was it for a while. I had stayed in gear for DFCO, but I never saw it happen, so I coasted in neutral whenever possible. I also realized that my mileage while accelerating was lousy regardless of how hard I accelerated, so I started getting to speed faster. I have always coasted as much as possible.
3#2 It is always entertaining to watch your mileage while coasting in neutral, but it seems to make a small difference overall. If you could get DFCO to work, your gauge would show 999.9 MPG, but you would be in-gear, so you would slow down faster. There are debates on here regarding which is better. Be careful!
3#3 I believe that in neutral, your engine is spinning less weight, so while it might spin slightly faster, it would be spinning less overall.
4. Have you calibrated your gauge yet? You can get the manual from
http://www.google.com/url?sa=t&rct=j...f1dvxrALTHgv5Q . You want to calibrate both the odometer and fuel. Once you calibrate the odometer, they will read differently, but I do not have any idea why they would be different before then.
5. According to
http://ecomodder.com/forum/showthrea...-use-2737.html , your alternator requires one to two horsepower, yet you can increase your mileage ten percent if you disable your alternator. That sounds very complicated, which they discuss in that thread. Some on here do AC deletes and others do power steering deletes. According to
Turning off the air conditioning helps save fuel, Swiss study finds , your air conditioning decreases your mileage by up to 30%, even though Mythbusters stated otherwise.
Another warning: Please do not ever use television to back up an argument on this site, especially g*lfball d*mples!
I am very surprised by the thirty percent figures. Maybe if you install a Febreeze dispenser and delete your air conditioning, power steering, and alternator you could be closer to one half, although it seems overly optimistic. My first thought is that there is a minimum idle RPM and if you tried to go below that, your call would stall.
However, you could install a kill switch:
http://ecomodder.com/forum/showthrea...-how-4356.html and
http://ecomodder.com/forum/showthrea...our-24263.html . Then you could coast in neutral and not use any gas. I believe that if you turn the key it shuts off your Ultragauge. Will someone please clarify?
Good luck!