[Christ]

Originally Posted by jamesqf

Because any modern engine has an ECU and sensors, that keep it in the proper range. If it was running far rich or lean, it would fail to meet its emissions standards.



No you don't need a reference point. You know what goes in - air and fuel in a particular ratio - you know what comes out - exhaust gasses containing a certain percentage of unburned hydrocarbons - and therefore you know, from simple math, how much of the fuel is unburned. Remember conservation of energy? Well, this is just the compliment, conservation of mass.

This is going to be one of those times we're just going to have to disagree and get on with it.