Paulgw and Big-Foot:

Your question and answer raise another interesting and related issue: Which does Toyota use to rate its Atkinson/Miller engines' displacement -- the intake stroke volume or the power stroke volume? The former is smaller than the latter because of the delayed intake valve closing, and it really ought to be the volume used for rating purposes, since the fuel consumed depends upon the intake stroke, not upon the longer power stroke (which is what gives the increased efficiency). I'd bet that it's the (longer) actual mechanical stroke volume (equal to the power stroke volume) that's actually used. Does anyone know the correct answer?

Stan