I just wanted to share this observation. I've been playing with my new Scangauge and figuring out what works and what doesn't. My car, 99 Ford ZX2 5 sp which I've only owned for a month never gets "hot" during normal driving.
Temp is barely in the normal range no matter how long it's running. Under these conditions a neutral coast at 55 mph registers 187 mpg with the scan gauge. Every day for the last week. Yesterday I'm playing the game and WHAM, the bain of a hypermiler, central NJ bumper to bumper traffic. In addition it was a little warmer than we've been experiencing, 50 deg. I notice the temp gauge well into the upper third of the range. Now I'm freaking watching my average drop as I inch ahead AHHHH. The traffic began to break up and I start rolling pretty good. I come to a decline @ 55 mph and I slip in from 5th to N and coast. The scangauge reads 248 mpg. i know this is anecdotal and I'm not trying to quantify any actual numbers but it has never done this. Now as I drive some more and the temp comes down and I coast @ 55 it reads ~187 mpg. I need to change my thermostat and get the temp of this engine up. I drove in this morning, 32 deg without using the heater, thinking this might help. It did. The temp was inthe middle of the range. My Scangauge average was 42.5 mpg when I got to work. This even with another back up on the upper 1/2 of my Parkway drive (5 miles). This is 1 mpg more than any of my previous trips without any traffic back up. Without the traffic it would have deffinitely been 43.5 mpg. Now I'm only using this as an indicator and not a definite number. I need to find a hotter thermostat and or block off radiator when it's cold. I have no idea what it's going to be once we see Spring/Summer temps.
I think Smokey was onto something
http://www.google.com/search?q=smoke...A&ved=0CDUQsAQ I understand this a lot more than chips and laptops with AFR/Spark tables