So this post is for all but particularly "RedYaris". Have you (or anyone else) tried installing a switch to manually stop alternator from charging. I would think that would add a little mpg. A person would have to test to see how long their battery would hold up. I know the newer motorcycles also run the lights all the time. That might have to be interrupted as well or battery would run down much sooner. Here I don't know if it is mandatory that the lights be on or not. Probably per state. If a person can get a pretty good handle on how far they can go without charging, it should not be a problem. If it is a problem, perhaps a bigger battery or supplemental battery could be installed. This, in affect, is making your rig somewhat of a hybrid. You could carry a small charger on board to plug in at work as well as home. This could also be done with cars!
Also, Redyaris, how come your car weighs 2300#? I would have thought it would be closer to 2000# but what do I know. My 98 Ford Escort weighs 2600 which I thought was kind of high as well.
tinkerbill