[MetroMPG]

SW again:

That looks like it would work for a single channel metric.

I'd be very surprised if you'd want to stop there with only the amperage over time w/o reference to what else is simultaneously going on. I was thinking of maybe a 4-channel or 8-channel multiplexed A/D. I'm sure I've tripped over things like that but now that I want one, I'd have to go digging.

EDIT (second try): the example above uses the ADC0831 single-channel 8-bit A/D converter chip. Also in the same family are ADC0834 (4-channel) and ADC0838 (8-channel). The 8-channel can be configured as either 8 directly addressed inputs or 4 differential inputs. That latter may become necessary if you want to measure things on both the high voltage side as well as the 12V system. You definately don't want to make the grounds of those 2 systems common to each other.