"Driving on the battery" has me wondering exactly how much
juice the engine requires.  Assume: engine only, no radiator
fan, no lights, no music.  How many amps per hour?  How
does it change with RPM?

With google, I found one mention that 30 amps is typical.
Another that the current to the coil is about 4 amps when
the points are closed.  I can't find anything else.

Does anyone know anything more exact about this?  Or how
to figure it out?  Fuel pump, ECU, coil--what else?

Richard