As we detailed in our First Drive report of the 2014 Honda Accord Plug-In Hybrid, the powertrain involved is a bit confusing for non-engineers to understand. Of course, you don't need to know, exactly, what's going on under the hood, but we were still curious about how the Accord PHEV integrates Eco mode with the adaptive cruise control. Specifically, does the ACC adjust speed to take maximum advantage of regenerative braking (and thus electric range)?
Honda PR Assistant Manager Jessica Fini helped us figure out the answer. Basically, there are two main differences between Eco and Normal mode when the adaptive cruise control is on. First, Eco mode has a more gentle gas pedal setting than Normal, and this applies to the ACC as well, but it doesn't take the ACC's speed setting into account. Second, since Eco mode provides less power to the air conditioner in order to maximize efficiency, it does the same when the ACC is on. And, it turns out there is no difference between Eco and Normal mode when it comes to how the regenerative brakes operate, whether the ACC is on or not.