For those that have a Scangauge or equivalent, I am curious as to what rpm your ICE runs at, relative to road speed, acceleration, and what is displayed by the ECO gauge? The graph below is a map of engine efficiency based on torque and rpm. It is for a Prius but I would expect the Camry ICE to be similar. The red line is the said to be the desired operating point for the hybrid synergy drive, depending on power desired from the ICE. What you should see as you ask for more torque (acceleration) is the rpm stay constant at about 1,100 rpm. Then at some point of higher acceleration the rpm will start to increase. Maximum efficiency is going to be reached when the rpm gets up to the 3000 rpm range.

I'm curious as to what it takes to do that when you accelerate away from a stop light up to the speed limit, or up to merge speed on an on ramp?