A miles per gallon gauge is a common instrument in
BMWs.  It is hooked to the ECU and the speedometer,
and reads the size and frequency of the injector
pulses.  It's kinda fun to play with - your instantaneous
mileage can go from infinite (downhill with throttle
closed) to less than 5MPG (full throttle acceleration
in first)

I wish Vanagons had that.  (van content)

tabe johnson / 87 westy