I think load feedback is important too, but it is "calculated" from lots of vehicle specific data and sensors. It is sorta what I'm getting at with tracking the change in acceleration over the fuel flow rate:
http://ecomodder.com/forum/showthrea...tml#post176541
It would be a rather arbitrary number, but when it peaks you are accelerating most efficiently.
re: batt voltage. There's 2 adc left. With so many options (map,maf,throttle position, various temps, a piezo?, 02 sensor, battery voltage, ???) and none the same on every car, it is a challenge to know what precisely to do with those ADC ahead of time. You are certainly free to experiment, I'd be most interested in whatever helps w/efficiency. Battery voltage could be nice when I'm sitting with the engine off but with an electric load, but if you have a wideband o2 sensor, well you can "reverse engineer" lots of values.
I think I might add a generic "gimme a reading from adc1 or adc2" option at some point, but without knowing what it is reading, or what it means, it will be hard to integrate into other computed values.