#4 Works when approaching a stop. Accelerating afterward you can spend 90 seconds at 15 mpg or 30 seconds at 10 mpg. Does anybody have a stock instant mpg meter? The only ones I know of are on the hybrids. The Scangauge might do it.
Edit: With that size engine it only costs maybe 2 mpg. I'd rather be cool than save three or four bucks a tank.
Quite a few of the new cars and trucks have instant and average mpg meters, the last one i "borrowed" that had a mpg meter was one of these,
http://img250.imageshack.us/img250/1325/test2je4.jpgThe instant milage guage will go below 1 mpg

On the flip side of that when i removed the lead out of my right foot and drove a little more normal i could average around 28 mpg on the highway with the AC and cruise control on.
And living in Florida the AC is worth every penny of the extra fuel it uses.