To the OP, if you are only going for a few more MPG, just slow down.
When I started modding my Jetta, I did so with the intention of at least keeping the same MPG or better. I have had 3 tanks over 900 miles, and had 10 straight tanks over 800 miles. It is possible, but only if I keep my...
Update for everyone.
I got home way before expected. Last night actually
Yellowstone got snowed out for me, and I was already a day ahead of schedule when that happened. Also missed Pikes Peak because of rain and low cloud cover.
I will upload and share...