After re-reading this entire thread, I was going to ask what your typical driving speeds were, but as I went through I see you aren't necessarily trying to hit/maintain the speed limit. That was a foreign concept to me until now. Do you aim for a certain speed for 6th gear? I ask because I can get just over 20mpg in 4th, but I can lately hit over 30mpg in 5th at 40-45mph...
A daily fuel log? Interesting concept. Makes me wonder if I can push my commute past 30mpg. May require me rearranging my daily drive to avoid morning rush hour.
I also did some Google searching and learned I can leave my block heater plugged in for extended periods. Thought I'd risk cooking something, so I've almost never had it plugged in more than 20 minutes... Gotta thank MetroMPG for posting stats on temp rise:
Experiment: how long should a block heater be plugged in? - MetroMPG.com
DD, ever look at a filtermag? I don't think it does anything for FE, but it does trap ferrous debris in the oil filter...
www.filtermag.com