I think that the rev counter on cars could be replaced by a counter that shows the current fuel efficiency.
This would be simple to do but what I wonder would be the formula for calculating it if you couldn't just measure the fuel intake against the speed.
What formula would apply then?
Feb 3rd 2010, 09:27 PM
This was common in New Zealand/Australia on Holdens (General Motors) and on Fords (late 1970's). If I remember correctly the guage was not calibrated and was marked somtheing like "Econo-guage". I believe that it was actualy a vacuum guage connected to the engine inlet manifold (or was that exhaust?).
Now my Ford Falcon (1997) displays this information on a digital display measured in litres per 100 kilometers. I don't know how they calculate it, but would not be at all surprised if it is just an estimate based on the inlet manifold vacuum.
Feb 4th 2010, 06:17 AM
It certainy should not be difficult to have a meter on the fuel feed that measures, say, L litres per hour. With the speedometer that measures K km per hour, km per litre would just K/L.