wow, I searched and searched (the internet, as well as physically on the car) for that nut in the integras. As a matter of fact, I was still completely clueless until you actually spelled it out lmao Ohh, well. thanks for helping me find it
I don't have a reference for the integra, but with my f-150 I got 1-2 mpg (5-9%) increase after starting eco-friendly driving techniques a couple years ago. It is just second-nature now. A cross-country drive in a friend's focus (with stock fuel economy readouts) helped a ton as well. It really surprised me about how very small changes in acceleration had a very big affect on my efficiency, especially since I had previously discounted them as insignificant.
Mine is a 5-spd GS as well (no vtec...). How many miles do you have on yours? This one recently topped the 200k mark, but it runs better than my f-150 (@~145k miles)... and my f-150 runs well. It rained today, and when I hopped in it, there was more water in it (different leak... probably sunroof this time). ugh. I'm falling in love with the car, though.